JP2006189823A - Electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that while minimizing an absorption of short-wavelength image exposure at its surface layer, is capable of maintaining excellence in electrophotographic performance, such as resolving power. <P>SOLUTION: The electrophotographic photoreceptor has a surface region layer superimposed on a photoconductive layer, wherein the surface region layer comprises a non-single-crystal silicon nitride film containing at least silicon and nitrogen atoms as a matrix wherein an element of Group 13 of the periodic table is contained, and the surface region layer includes a variation layer in which the constituent ratio of silicon and nitrogen atoms is varied and a surface layer in which the constituent ratio is unchanged. The variation layer has, in the direction of the thickness, at least one maximum value of the content of the element of Group 13 of the periodic table based on the total number of constituent atoms, and the surface layer also has, in the direction of the thickness, at least one maximum value of the content of the element of Group 13 of the periodic table based on the total number of constituent atoms. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophotographic photosensitive member, and more particularly to an electrophotographic photosensitive member that is optimal for printers, facsimiles, copying machines, and the like that use light having a relatively short wavelength of 380 nm to 500 nm for exposure.

In the field of image formation, as a photoconductive material in a photoreceptor,
1. High sensitivity and high SN ratio (photocurrent (Ip) / dark current (Id)).
2. It has an absorption spectrum that matches the spectral characteristics of the electromagnetic wave to be irradiated.
3. Photoresponsiveness is fast and has a desired dark resistance value.
4). Harmless to human body during use.
Etc. are required.

  In particular, in the case of an electrophotographic photosensitive member incorporated in an electrophotographic apparatus used in an office as an office machine, the pollution-free property at the time of use is an important point.

  An amorphous silicon (hereinafter abbreviated as a-Si) is a photoconductive material exhibiting excellent characteristics that satisfy the above-described characteristics, and has attracted attention as a light receiving member of an electrophotographic photosensitive member.

  In general, a photoreceptor having a photoconductive layer made of a-Si is generally formed on a conductive substrate heated to 50 ° C. to 350 ° C. by vacuum deposition, sputtering, ion plating, thermal CVD, or photo CVD. And a film forming method such as a plasma CVD method. Among these, the plasma CVD method in which the source gas is decomposed by high frequency or microwave glow discharge and an a-Si deposited film is formed on the substrate has been put to practical use.

  For example, in Patent Document 1, the surface layer of an a-Si photoconductor is composed of a-Si containing at least one of nitrogen, carbon, and oxygen, and the content in a-Si is described as follows. A technique for continuously increasing toward the outermost surface is disclosed.

  Further, in Patent Document 2, when a load is applied to a diamond needle having a tip diameter of 0.8 mm and the surface of the photoreceptor is scratched, no scratches on the surface of the photoreceptor are observed, The dark part potential holding ability of the portion is significantly lowered. For the purpose of preventing an image defect called an image defect that causes an image defect on the image, the content of the Group 13 element in the periodic table in the amorphous layer region based on silicon laminated on the photoconductive layer is: A technique of taking a distribution having at least two maximum values in the thickness direction of the layer region is disclosed.

  However, even if an image is output using an electrophotographic photosensitive member in which the surface layer as described above is deposited on the photoconductive layer, interference occurs when an electrostatic latent image is formed by image exposure, and the image quality is reduced. May decrease. In order to improve this defect, Patent Document 3 clearly discloses that the composition is continuously changed from the photoconductive layer to the surface layer when the photoconductive layer and the surface layer are formed by plasma CVD. A technique for preventing interference without creating a reflecting surface is disclosed.

  These techniques have improved the electrical, optical, and photoconductive characteristics of the electrophotographic photosensitive member and the usage environment characteristics, and the image quality has been improved accordingly.

  In addition to the recent demand for higher image quality, there has been an increasing demand for higher-definition electrostatic latent images along with toner particle size reduction. For this purpose, for example, in the case of a digital copying system, there is a method of reducing the spot diameter of a laser used for image exposure. For this purpose, it has been required to shorten the wavelength of the laser.

During image exposure, a laser beam having an oscillation wavelength of 600 to 800 nm, which is generally used conventionally, is emitted from a-Si using an ultraviolet blue-violet laser oscillator having a main oscillation wavelength of 380 to 450 nm. A technique for exposing the photosensitive layer is disclosed in, for example, Patent Document 4 and the like.
JP 7-306539 A JP 2004-133399 A JP-A-6-242624 JP 2000-258938 A

  Conventional a-Si-based electrophotographic photoreceptors have electrical resistance, photosensitivity, photoresponsiveness, and other electrical, optical, photoconductive characteristics, and usage environment characteristics, as well as stability over time and durability. In this respect, the characteristics are improved. However, in reality, there is room for further improvement in improving overall characteristics.

  In particular, in recent years, there has been a rapid shift to digitalization and colorization, and high image quality (high resolution, high definition, no density unevenness, image defects (white spots, The demand for such as no sunspots) is increasing more than before.

  In order to increase the resolution of an image, it is effective to reduce the spot diameter of laser light for image formation. Examples of means for reducing the spot diameter of the laser beam include improving the accuracy of the optical system that irradiates the photoconductive layer with the laser beam and increasing the aperture ratio of the imaging lens. However, this spot diameter can only be reduced to the diffraction limit determined by the wavelength of the laser beam and the aperture ratio of the imaging lens. For this reason, reducing the spot diameter while keeping the wavelength of the laser light constant necessitates an increase in the size of the lens and an improvement in mechanical accuracy, and it has been difficult to avoid an increase in size and cost of the apparatus.

  Therefore, in recent years, focusing on the fact that the lower limit of the spot diameter of laser light is directly proportional to the wavelength of the laser light, a technique for reducing the spot diameter by shortening the wavelength of the laser light and increasing the resolution of the electrostatic latent image. Is attracting attention.

  In conventional electrophotographic apparatuses, laser light having an oscillation wavelength of 600 to 800 nm is generally used for image exposure, and the resolution of the image can be increased by further shortening this wavelength. In recent years, semiconductor lasers having a short oscillation wavelength have been rapidly developed, and semiconductor lasers having an oscillation wavelength around 400 nm have been put into practical use.

  In order to increase the resolution of an image by such a method, further improvement is required particularly in the material and layer structure of the surface layer so that the photoconductor can cope with light in such a short wavelength band. That is, it is necessary that the photosensitive layer has sufficient sensitivity with respect to the image exposure wavelength, and the light exposed in the surface layer needs to be hardly absorbed. Furthermore, it is necessary to minimize the interference of laser light in a short wavelength band by the reflecting surfaces of the photoconductive layer and the surface layer.

  For example, an a-Si-based photosensitive layer has a sensitivity peak in the vicinity of 600 to 700 nm and is slightly inferior to the peak sensitivity. However, if the conditions are devised, the sensitivity is also in the vicinity of 400 to 410 nm. , Even when a 405 nm short wavelength laser is used. However, the sensitivity may be about half of the peak, and it is preferable that there is almost no light absorption in the surface region.

  When the present inventors examined an electrophotographic photosensitive member having an amorphous silicon nitride (hereinafter also referred to as a-SiN) as a surface layer, the absorption coefficient near 400 to 410 nm can be lowered by optimizing the conditions. I found out. However, in response to the recent demand for higher image quality of digital full-color copiers, it has become necessary to improve the overall characteristics of the photoreceptor corresponding to higher image quality. Specifically, it is important to improve the dot reproducibility more than before, and at the same time, how to improve the surface layer so that desired characteristics can be maintained is important.

  Thus, there is a need for a surface layer material that is a film that hardly absorbs light with a short wavelength in the vicinity of 400 to 410 nm and that can achieve high resolution without impairing electrophotographic characteristics. There has been a strong demand for an electrophotographic photoreceptor including a conductive surface layer.

  That is, first, it is necessary that exposure at short wavelengths in the vicinity of 400 to 410 nm is hardly absorbed in the surface region. The second is to have a sufficient function of preventing the injection of negative charges from the surface, and the third is to have a high resolution that can make use of a small spot diameter & small particle diameter toner.

  The present inventors have solved the above-mentioned problems, can be suitably used for high-quality, high-durability, and high-speed copying processes, have practically sufficient sensitivity for short wavelength exposure, have high charging ability and high contrast. In order to realize the copying process, intensive study was conducted. As a result, a silicon nitride-based material is used as the surface layer, and the content distribution of the Group 13 elements in the periodic table in the surface region layer is reduced while minimizing interference caused by reflection between the photoconductive layer and the surface layer. The inventors have found that the above-described object can be satisfactorily achieved by controlling the above, and have reached the present invention.

  That is, the present invention provides a photoconductive layer composed of a non-single-crystal silicon film containing at least silicon atoms as a base material on a conductive substrate, and a matrix of silicon atoms and nitrogen atoms stacked on the photoconductive layer. And a surface region layer made of a non-single-crystal silicon nitride film containing at least a part of Group 13 element of the periodic table, and the surface region layer has a period with respect to the total number of constituent atoms in the film thickness direction. It is an electrophotographic photosensitive member having at least two local maximum values of the group 13 element content.

  The present invention also provides a photoconductive layer formed of a non-single-crystal silicon film having at least silicon atoms as a base material on a conductive substrate, and silicon atoms and nitrogen atoms stacked on the photoconductive layer as a matrix. And a surface region layer made of a non-single-crystal silicon nitride film containing at least a part of Group 13 element of the periodic table, and the surface region layer has a composition ratio of silicon atoms and nitrogen atoms changed. An electrophotographic photosensitive member having a change layer and a surface layer having a constant composition ratio of silicon atoms and nitrogen atoms, wherein the change layer includes a group 13 element of the periodic table with respect to the total number of constituent atoms in the thickness direction of the film. It has at least one maximum value of the content rate, and the surface layer further has at least one maximum value of the content rate of the group 13 element of the periodic table with respect to the total number of constituent atoms in the thickness direction of the film. With an electrophotographic photoreceptor That.

  According to the present invention, it is possible to provide an electrophotographic photoreceptor capable of improving electrophotographic characteristics such as resolving power while minimizing the absorption of short-wavelength image exposure on the surface layer.

  The present inventors have prepared a thin film of an a-SiN material suitable as a surface layer, but found that depending on the preparation conditions, it is possible to suppress absorption of light having a short wavelength, for example, light having a wavelength of 400 to 410 nm. It was. It has been found that the photoreceptor having such a surface layer has sufficient sensitivity to light having a wavelength in the vicinity of 400 to 410 nm. Specifically, a film with less absorption can be obtained by optimizing the source gas type, the flow rate and ratio of the source gas, the ratio of input power to the gas amount, and the like.

  The film prepared under such conditions was analyzed by XPS (X-ray photoelectron spectroscopy), RBS (Rutherford backscattering spectroscopy), SIMS (secondary ion mass spectrometry) and the like. As a result, it was found that the nitrogen content range is preferably 30 atomic% or more when expressed as N / (Si + N) as an acceptable value for absorption at a practical film thickness.

  Further, it was found that the upper limit is preferably 70 atomic% or less from the relationship of the film yield. If it is 70 atomic% or less, unevenness such as film thickness, hardness, and resistance hardly occurs, and the strength of the film can be maintained, and the film can be stably manufactured at a high yield. If it is 70 atomic% or less, it has desirable characteristics for use as a surface layer, but if it exceeds 70 atm%, unevenness such as film thickness, hardness, and resistance tends to occur, and the yield may be greatly reduced. The cause is expected to be because too much nitrogen makes the membrane bonds very unstable. Further, it was found that the range of 70 atomic% or less is preferable when used as a surface layer because the strength of the film can be maintained.

  As described above, an a-SiN film having a short wavelength and low light absorption can be obtained by optimizing the preparation conditions. However, such a film has a high volume resistance of the film itself and may have a large residual potential. In some cases, it may become an impediment to achieving high image quality corresponding to. Furthermore, it is necessary to minimize interference due to reflection between the photoconductive layer and the surface layer.

In the surface layer, the content of the group 13 element in the periodic table has a distribution having at least one maximum value in the thickness direction of the film.
1. The residual potential can be reduced, and the image quality can be further improved.
2. An electrophotographic characteristic is obtained in which the charging property is improved and the optical memory is also suppressed.
3. The ability to prevent charge injection from the outermost surface is improved, and the charging ability is further improved.
I found out.

  The reason why these effects can be obtained is not clear, but by adding a group 13 element of the periodic table, relaxation of bonds occurs in the a-SiN film, which originally has a large film stress, and as a result, defects are reduced. It is presumed that the carrier runnability has increased and the residual potential has been lowered.

  If the surface layer film is reduced in defects so that the residual potential can be lowered in this manner, the number of shallow traps in the film is reduced, and for example, carriers trapped in the trap after charging are re-emitted before development. It will not be excited. Originally, carriers coming out of such shallow traps are considered to drift so as to fill in the potential difference caused by the latent image formation, so that the latent image is blurred and the depth of the latent image is reduced. it is conceivable that. Therefore, if the traps can be reduced, the cause of blurring the latent image is reduced and the resolution is increased.

  In order to minimize interference due to reflection between the photoconductive layer and the surface layer, it is effective to provide a change layer in which the composition ratio of silicon atoms to nitrogen atoms continuously changes. Specifically, the minimum value (Min) and the maximum value (Max) of the reflectance (%) in the wavelength range of 350 nm to 680 nm are 0% ≦ Max (%) ≦ 20% and 0 ≦ (Max−Min) / ( It is preferable to provide the change layer so as to satisfy 100−Max) ≦ 0.15. Here, the reflectance refers to the value of reflectance (percentage) measured using a spectrophotometer (MCPD-2000 manufactured by Otsuka Electronics Co., Ltd.). Specifically, the spectral emission intensity I (o) of the light source of the spectroscope was taken, and then the spectral reflection light intensity I (D) of the photoconductor was taken to obtain the reflectance R = I (D) / I (o). Is.

  As in the present invention, it is possible to prevent the appearance of image density unevenness due to scraping of the surface layer by minimizing interference due to reflection between the photoconductive layer and the surface layer.

  Furthermore, the present inventors have made various revisions to the conditions for creating the surface region layer, focusing on the charging ability and image defects. As a result, the content of nitrogen element with respect to the total number of constituent atoms in the surface region layer has at least two maximum values in the thickness direction of the film, thereby reducing the absorption coefficient of light having a wavelength of 500 nm or less in the surface region layer. The charging ability was improved while suppressing the image defects. This effect can be remarkably obtained when the two maximum values of the nitrogen atom content rate and the two maximum values of the group 13 element content rate of the periodic table are alternately arranged in the film thickness direction. I understood. Furthermore, it has been found that when the photoconductive layer side is arranged in this order from the photoconductive layer side toward the free surface, the maximum value of the group 13 element content of the periodic table and the maximum value of the nitrogen atom content rate are arranged in this order. This is because, by reducing the nitrogen concentration in the region where the group 13 element of the periodic table is added, the valence electron controllability is improved and the ability to prevent charge injection from the outermost surface is further improved. Conceivable. In addition, regarding the suppression of image defects, the ability to prevent charge injection is further improved, and the ability to prevent charged charges that escape to the substrate side through the interface between the projections of the deposited film and the normal deposition part is obtained. This is thought to be due to the improvement. In addition, the distance between the maximum value on the photoconductive layer side and the minimum value between the two maximum values among the two adjacent maximum values in the thickness direction of the content ratio of nitrogen atoms with respect to the total number of constituent atoms is 40 nm or more. If it exists, effects such as improvement of charging ability and suppression of image defects can be obtained. Furthermore, if the distance is in the range of 300 nm or less, the sensitivity to short wavelength exposure can be sufficiently obtained.

  Furthermore, the inventors have made various changes to the surface layer preparation conditions, focusing on the film structure of a-SiN, and improved the cleaning properties by adding oxygen atoms and / or fluorine atoms. It was found that it was possible to

  The a-SiN film is relatively easy to show a columnar structure depending on the preparation conditions. However, when there are many such columnar structures, it is considered that there are many structural boundaries appearing on the surface. In such a state, there is no transfer residue or cleaning residue. Prone to occur. However, the addition of oxygen atoms and / or fluorine atoms resulted in a decrease in transfer residue and cleaning residue. As described above, the progress of low defect progress and reduction of the columnar structure resulted in a decrease in the structure boundary appearing on the surface. I believe.

  Furthermore, when the present inventors have repeatedly studied the addition of oxygen atoms and / or fluorine atoms, the inclusion of the surface layer so as to have a maximum value shows no adverse effects such as a decrease in hardness and an increase in residual potential. In other words, it was effective for cleaning the transfer residue and cleaning residue. As described above, the oxygen atom or the fluorine atom added so as to have the maximum value in the surface layer can be obtained even if each is added alone, but in addition, both the oxygen atom and the fluorine atom have the maximum value. It was found that the addition was more preferable.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view showing an example of the layer structure of the electrophotographic photosensitive member in the present invention.

  In the electrophotographic photosensitive member shown in FIG. 1A, a photoconductive layer 102 and a surface region layer 103 are formed in this order on a conductive substrate 101. In the electrophotographic photosensitive member shown in FIG. 1B, a lower injection blocking layer 104, a photoconductive layer 102, and a surface region layer 103 are formed in this order on a conductive substrate 101. In the electrophotographic photoreceptor shown in FIG. 1C, a lower injection blocking layer 104, a photoconductive layer 102, a surface region layer 103a including a change layer 109 and a surface layer 108a are formed in this order on a conductive substrate 101. Yes.

  The lower injection blocking layer 104 is not essential, but is preferably provided to prevent charge injection from the conductive substrate side.

  In the surface region layer 103, a first upper injection blocking layer 105 (TBL-1), an intermediate layer 106, a second upper injection blocking layer 107 (TBL-2), and a surface protective layer (SL) 108 are formed in this order. Yes.

  Here, it is preferable to provide a change layer 109 on the photoconductive layer 102 side in the surface region layer 103a so that the refractive index changes continuously with the photoconductive layer 102.

  If there is a difference in the refractive index between the surface layer 110 and the photoconductive layer 102, interference will occur at the interface between the layers, and the sensitivity will be fluctuated due to shaving. End up. In order to prevent this, the change layer 109 gently changes the refractive index by gently changing the composition of the film, and the difference in refractive index between the surface layer 110 and the photoconductive layer 102 is gently connected. As a result, light reflection at the layer interface due to the difference in refractive index between the surface region layer 103a and the photoconductive layer 102 is suppressed, and interference at the interface when coherent light is used for exposure is prevented.

  Here, each layer mentioned above is demonstrated in detail.

<Surface region layer>
The surface region layers 103 and 103a in the present invention are provided mainly for obtaining good characteristics with respect to short wavelength light transmittance, high resolution, continuous repeated use resistance, moisture resistance, use environment resistance, good electrical characteristics, and the like. Yes. In the case of an electrophotographic photosensitive member for positive charging, it also serves as a charge holding layer. Even in the case of a negatively charged electrophotographic photosensitive member, it may have a role as a charge holding layer itself, but it is more flexible to design a surface layer if the change layer described later has a charge holding function. It is preferable from the point.

  The surface region layer 103a in the present invention has a surface layer 110 and a change layer 109, and the material thereof is a non-single material in which a silicon atom and a nitrogen atom are used as a base material and a group 13 element of the periodic table is appropriately contained at least in part. Made of crystalline material. Further, it is preferable that a hydrogen atom, an oxygen atom and / or a fluorine atom are appropriately contained in the film. At this time, the amount of nitrogen contained in the surface layer 110 is preferably in the range of 30 atomic% to 70 atomic% with respect to the sum of the number of silicon atoms and nitrogen atoms.

  In the surface region layer 103a of the present invention, it is important that the content of the Group 13 element in the periodic table has at least one maximum value in the thickness direction of the film in each of the change layer 109 and the surface layer 110. It is.

  Here, among the maximum values of the group 13 element content of the periodic table, it is preferable that the maximum value located closest to the photoconductive layer side of the change layer is the largest in terms of improving electrical characteristics.

  Further, in order to improve the electric characteristics such as charging ability and the resolution such as dot reproducibility, the distance between two adjacent maximum values of the group 13 element content of the periodic table is 100 nm or more and 1000 nm in the film thickness direction. The following range is preferable.

Further, in order to improve the electrical characteristics such as charging ability and the resolution such as dot reproducibility, the maximum value of the group 13 element of the periodic table located closest to the photoconductive layer is 5.0 × 10 ¹⁸ pieces / cm 3. ³ or more
It is also preferable that the minimum value of the group 13 element of the periodic table existing between two adjacent maximum values is 2.5 × 10 ¹⁸ elements / cm ³ or less.

  FIG. 4 is a schematic concentration profile of each element in the surface region layer. As shown in FIG. 4, the boron (periodic group 13 atom), carbon, fluorine and oxygen atoms in the surface region layer are the maximum of boron (periodic group 13 atom), carbon, fluorine and oxygen atoms on the outermost surface side. The maximum value of boron is formed at a position where the value is deeper and closer to the photoconductive layer side. That is, the maximum values of carbon, fluorine and oxygen atoms are observed at one place, and the maximum values of boron are observed at two places.

  Further, the surface region layers 103 and 103a have at least two maximum values of the nitrogen atom content in addition to the maximum value of the group 13 element content of the periodic table with respect to the total number of constituent atoms in the thickness direction. It is preferable. The number of the maximum value of the content rate of the group 13 element of the periodic table and the maximum value of the content rate of the nitrogen atom may be at least 2 each, for example, 2 each, 3 each, or 2 each The other may be a different number, such as three or four. These maximum values may be located anywhere in the thickness direction of the surface region layer. For example, as shown in the graph showing the contents of the periodic table group 13 element and nitrogen atom in FIG. May be present at the same position in the thickness direction. Moreover, as shown in the graph showing content of a periodic table group 13 element and nitrogen atom of FIGS. 9-13, it is preferable to locate alternately. In this case, it is preferable that the photoconductive layer side has a maximum value of the group 13 element content of the periodic table, so that the charging ability can be increased, and if the free surface side has a maximum value of the nitrogen atom content rate, It is particularly preferable from the viewpoint of scratch resistance and abrasion resistance of the body. As the surface region layer having such a maximum value, two or more upper injection blocking layers each having a maximum value of the group 13 element content of the periodic table in the thickness direction, for example, the first upper injection blocking layer 105, the second upper injection blocking layer 107. In addition, one or more intermediate layers 106 each having a maximum value of nitrogen atom content in the thickness direction are alternately provided on the photoconductive layer, and have a free surface as the outermost layer. A surface protective layer 108 having one maximum value of the content of nitrogen atoms in the direction may be provided.

  In the present invention, in order to form the maximum content of the group 13 element of the periodic table in the film thickness direction, the supply of the group 13 element of the periodic table is controlled while the surface region layer 103 is being formed. Can be obtained. Control of group 13 element supply of the periodic table should be performed by appropriately changing the growth conditions such as the flow rate and concentration of the group 13 element supply gas of the periodic table, the flow rate of the silicon / nitrogen atom supply gas as the base material, and the growth temperature. Can do.

Here, specific examples of Group 13 elements of the periodic table include boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and boron is particularly preferable. is there. Further, as the supply gas for the Group 13 element of the periodic table, specifically, B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B ₆ H ₁₀ , B ₆ H ₁₂ , B ₆ Examples thereof include boron hydrides such as H ₁₄ and boron halides such as BF ₃ , BCl ₃ , and BBr ₃ . In addition, AlCl ₃ , GaCl ₃ , Ga (CH ₃ ) ₃ , InCl ₃ , TlCl _{3 and the} like can also be mentioned.

  Here, an example of the maximum value of the present invention will be described with reference to FIG.

    FIG. 7 schematically shows an example of a state in which there is a maximum value of the content distribution of the group 13 element of the periodic table at one place in each of the change layer and the surface layer of the surface region layer.

  In the present invention, the maximum value of the content of the group 13 element in the periodic table is preferably a shape in which the peak exists at the maximum value of the content as shown in FIG. . Moreover, the distance between maximum values shows the distance shown in FIG.

  When the content rate has a certain region, the center of the certain region is set as the position of the maximum value.

  As for the maximum value of the content of oxygen atoms and / or fluorine atoms, it is preferable that the maximum value of the content of the group 13 element of the periodic table shown in FIG. In a film such as a-SiN having a large stress, a shape that does not have a constant region in the content rate distribution forms a local region that effectively relaxes stress than a shape that has a constant region. As a result, stress relaxation of the entire film is considered to proceed efficiently, so it is preferable to control so that a constant region does not occur in the content rate distribution.

  In addition, the shape that does not have a constant region in the content rate distribution can be expanded by locally providing a region where the carrier spreads easily, which reduces dot reproducibility and fine line reproducibility, when moving the photocarrier by image exposure. I think it can be kept small.

The content of oxygen atoms or fluorine atoms in the surface layer 110 is based on the total number of constituent atoms.
The average concentration in the film is preferably 0.01 atomic% or more and 20 atomic% or less. It is more preferably 0.1 atomic percent or more and 10 atomic percent or less, and further preferably 0.5 atomic percent or more and 8 atomic percent. In order to adjust the content within such a range, for example, an oxygen atom or fluorine atom containing gas such as NO or SiF ₄ is diluted with a gas such as H ₂ , He, Ne and Ar, and a mass flow controller is used. It is only necessary to control the flow rate through the medium.

  The surface layer 110 preferably contains hydrogen atoms, but the hydrogen atoms compensate for dangling bonds of silicon atoms and improve layer quality, particularly photoconductivity and charge retention. In general, the hydrogen content is preferably 5 to 70 atom%, more preferably 8 to 60 atom%, more preferably 10 to 50 atoms as an average value in the film with respect to the total amount of constituent atoms. % Is more preferable.

Examples of a substance that can serve as a silicon (Si) supply gas used in forming the surface layer 110 include gaseous substances such as SiH ₄ , Si ₂ H ₆ , Si ₃ H _8, and Si ₄ H ₁₀ , or hydrogen that can be gasified. Silicon oxide (silanes) can be mentioned as being effectively used. SiH ₄ and Si ₂ H ₆ are preferable from the viewpoints of easy handling at the time of layer preparation and good Si supply efficiency. These source gases for supplying Si may be diluted with a gas such as H ₂ , He, Ar, Ne or the like as necessary.

As substances that can serve as nitrogen or oxygen supply gas, gaseous substances such as N ₂ , NH ₃ , NO, N ₂ O, NO ₂ , O ₂ , CO, and CO ₂ , or compounds that can be gasified are effectively used. Can be mentioned. Among them, nitrogen is preferable as the nitrogen supply gas because the best characteristics can be obtained. Similarly, NO is preferable as the oxygen supply gas. These source gases for supplying nitrogen and oxygen may be diluted with a gas such as H ₂ , He, Ar and Ne as necessary. In particular, when a small amount of oxygen is added, the flow rate can be accurately controlled, for example, by diluting and supplying NO gas with He gas in advance.

For supplying fluorine atoms, silicon fluoride such as SiF ₄ and Si ₂ F ₆ and halogen such as fluorine gas (F ₂ ), BrF, ClF, ClF ₃ , BrF ₃ , BrF ₅ , IF ₃ and IF ₇ are used. An intercalation compound may be introduced.

Further, as the oxygen atom and fluorine atom supply gas, a plurality of the above gases may be mixed. In particular, the oxygen atom supply gas is most preferably NO or a mixed gas containing NO and appropriately diluted with a diluent gas such as He. As the fluorine atom supply gas, SiF ₄ is the most preferable example. When these gases were used, the most preferable results were obtained with the electrophotographic characteristics viewed in total.

  In order to form the surface region layer 103a, it is necessary to appropriately set the gas pressure of the reaction vessel, the discharge power, and the temperature of the substrate. The optimum range of the substrate temperature is appropriately selected according to the layer design. In general, it is preferably 150 ° C. or higher and 350 ° C. or lower, more preferably 180 ° C. or higher and 330 ° C. or lower, and 200 ° C. or higher and 300 ° C. or lower. More preferably, it is as follows.

Similarly, the optimum range of the pressure in the reaction vessel is appropriately selected according to the layer design, but in the usual case, it is preferably 1 × 10 ⁻² Pa or more and 1 × 10 ³ Pa or less. It is more preferably 5 × 10 ⁻² Pa or more and 5 × 10 ² Pa or less, and further preferably 1 × 10 ⁻¹ Pa or more and 1 × 10 ² Pa or less.

  The layer thickness of the surface layer 110 is preferably 0.1 to 3 μm, more preferably 0.15 to 2 μm, and still more preferably 0.2 to 1 μm.

  If the layer thickness is greater than 0.01 μm, the surface side layer region will not be lost due to wear or the like during use of the light receiving member, and if it does not exceed 3 μm, the electrophotographic characteristics such as an increase in residual potential will deteriorate. Will not occur.

  In the present invention, the above-mentioned range is mentioned as a desirable numerical range of the temperature and gas pressure of the conductive substrate for forming the surface region layer 103a, but the conditions are usually not independently determined separately, It is preferable to determine an optimum value based on mutual and organic relations.

  In the present invention, the change layer gently changes the refractive index by gently changing the composition of the film, and the difference in refractive index between the surface layer 110 and the photoconductive layer 102 is gently connected. As a result, the influence of interference due to reflection of light at the interface between the photoconductive layer 102 and the surface layer 110 can be reduced, and further, the charge from the top (that is, from the surface layer side) can be added by adding a group 13 element of the periodic table. The effect of preventing the intrusion and improving the charging ability is also obtained.

Further, in the present invention, the change layer 109 has a minimum value (Min) and a maximum value (Max) of reflectance (%) in the light wavelength range of 350 nm to 680 nm at the interface between the photoconductive layer 102 and the surface layer 110. Are preferably optically continuous so that 0% ≦ Max (%) ≦ 20% and 0 ≦ (Max−Min) / (100−Max) ≦ 0.15.

  The layer thickness of the change layer is preferably 5 nm or more and 1000 nm or less, more preferably 10 nm or more and 800 nm or less, and more preferably 15 nm or more and 500 nm or less in view of obtaining desired electrophotographic characteristics and economic effects. More preferably. If the layer thickness is 5 nm or more, the charge injection stopping ability from the surface side is sufficient, and sufficient charging ability is obtained, so that the electrophotographic characteristics are not deteriorated. Improvement can be expected, and characteristics such as sensitivity are not deteriorated.

Similarly, the optimum range of the pressure in the reaction vessel is appropriately selected according to the layer design, but it is preferably 1 × 10 ⁻² Pa or more and 1 × 10 ³ Pa or less, preferably 5 × 10 ⁻² Pa or more and 5 × 10 6. It is more preferably ² Pa or less, and further preferably 1 × 10 ⁻¹ Pa or more and 1 × 10 ² Pa or less.

  Further, the optimum range of the substrate temperature is appropriately selected according to the layer design. In general, it is preferably 150 ° C. or higher and 350 ° C. or lower, more preferably 180 ° C. or higher and 330 ° C. or lower, 200 More preferably, it is at least 300 ° C.

<Upper injection blocking layer (TBL)>
The upper injection blocking layer provided in the surface region layer in the present invention is made of a non-single-crystal silicon nitride film having silicon atoms and nitrogen atoms as base materials, and has a maximum content ratio in the thickness direction of Group 13 elements of the periodic table. It is preferable to have one. By containing the Group 13 element of the periodic table, the photoconductor has a function of preventing the charge from being injected from the surface side to the first layer side when the free surface is subjected to a negative charging process. Specific examples of such group 13 elements in the periodic table include boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). Boron is particularly easy to handle. From the point of view, it is preferable.

The shape of the maximum value may have a peak as shown in FIGS. 9 (a), 10, 11 (a) and (b), and FIG. 13, but FIG. 9 (b) As shown in FIG. 12, it may be one having a constant value in a certain length in the thickness direction (referred to as a maximum region). In such a maximum region, as shown in FIGS. 14 (a) and 14 (b), a value at a half position of the thickness having the maximum region is set as a maximum value (the same applies hereinafter). As shown in FIG. 15 (b), the upper injection blocking layer (TBL-1, TBL-2, TBL-3) may be provided with two layers sandwiching the intermediate layer, but as shown in FIG. 15 (a). In this way, three layers may be provided with the intermediate layer interposed therebetween. The maximum value in the thickness direction of the content of the group 13 element of the periodic table provided one by one in each upper injection blocking layer is that the maximum value located on the most free surface side is the largest, sensitivity, potential unevenness, It is preferable in terms of optical memory, transparency, and cleaning properties. The maximum value is preferably 50 atmppm or more and 3000 atmppm or less, more preferably 100 atmppm or more and 1500 atmppm or less with respect to the total number of constituent atoms of the upper injection blocking layer. Specific examples of the content of the Group 13 element in the periodic table at the maximum maximum value are 5.0 × 10 ¹⁸ elements / cm ³ or more. The content of the group 13 element of the periodic table in the minimum direction of the minimum value of the group 13 element of the periodic table in the later-described intermediate layer where the content ratio of the group 13 element of the periodic table is low with respect to the maximum value of the group 13 element in the thickness direction However, it is preferably 2.5 × 10 ¹⁸ / cm ³ or less from the viewpoint of sensitivity characteristics. However, it is within the same plane that Group 13 elements of the periodic table having a maximum value in the thickness direction and contained in a non-uniform distribution are uniformly contained in a uniform distribution in the plane parallel to the surface of the substrate. It is preferable from the viewpoint of making the characteristics uniform.

  The maximum value of the Group 13 element of the periodic table is at a distance of 100 to 1000 nm from the maximum value of the adjacent Group 13 element of the periodic table. It is preferable from the point.

  The upper injection blocking layer preferably contains oxygen atoms as necessary. The nitrogen atoms or oxygen atoms contained in the upper injection blocking layer may be uniformly distributed in the layer, or may be unevenly distributed in the thickness direction. However, in any case, in the plane parallel to the surface of the substrate, it is necessary to uniformly contain these atoms in a uniform distribution from the viewpoint of uniform characteristics in the same plane.

  The content of nitrogen atoms contained in each layer of the upper injection blocking layer in the present invention is determined as appropriate so that the object of the present invention can be effectively achieved. When oxygen atoms are not contained, silicon atoms and nitrogen are contained. The range is preferably 10 atm% or more and 70 atm% or less with respect to the total number of atoms. More preferably, it is 15 atm% or more and 65 atm% or less, More preferably, it is 20 atm% or more and 60 atm% or less. In the case of containing oxygen atoms, the nitrogen atom or oxygen atom content is preferably in the range of 10 atm% to 70 atm% with respect to the total number of nitrogen atoms, oxygen atoms, and silicon atoms, respectively. More preferably, it is 15 atm% or more and 65 atm% or less, More preferably, it is 20 atm% or more and 60 atm% or less.

  Further, the upper injection blocking layer preferably contains hydrogen atoms and / or halogen atoms, which are combined with dangling bonds of silicon atoms to improve layer quality, in particular, photoconductive properties and charge. This is to improve the retention characteristics. The content of hydrogen atoms is, for example, 30 atm% or more and 70 atm% or less, preferably 35 atm% or more and 65 atm% or less, more preferably 40 atm% or more and 60 atm% or less with respect to the total amount of constituent atoms. The halogen atom content is, for example, from 0.01 atm% to 15 atm%, preferably from 0.1 atm% to 10 atm%, more preferably from 0.5 atm% to 5 atm%.

  It is also preferable that the composition of the upper injection blocking layers 105 and 107 is continuously changed from the photoconductive layer 102 toward the surface protective layer 108, which is effective in improving adhesion and preventing interference.

  The thickness of each of the upper injection blocking layers is such that desired electrophotographic characteristics can be obtained, and economical effects such as efficient production, etc. It is related to the distance between the minimum value between two adjacent maximum values in the thickness direction of the content rate and the maximum value on the photoconductive layer side. Specifically, as the thickness of the upper injection blocking layer, specifically, in order to appropriately set the distance between the maximum values of the group 13 atom content in the periodic table in the thickness direction of the adjacent upper injection blocking layer, for example, 10 nm or more and 1000 nm It can be as follows. Preferably they are 30 nm or more and 800 nm or less, More preferably, they are 50 nm or more and 500 nm or less. When the layer thickness is 10 nm or more, sufficient charging ability to prevent charge injection from the surface side can be obtained, and good electrophotographic characteristics can be obtained. Further, when the layer thickness is 1000 nm or less, an improvement in electrophotographic characteristics can be expected, and good sensitivity characteristics can be obtained. The film thickness of the second upper injection blocking layer (TBL-2) 107 is preferably 10 nm or more and 300 nm or less in order to improve the potential characteristics of the photoreceptor and the sensitivity characteristics.

Such an upper injection blocking layer can be formed by a plasma CVD method or the like. As the formation of the upper injection blocking layer by the plasma CVD method, a Si supply gas, an N supply gas, a gas for supplying a group 13 element of the periodic table, and a gas for supplying a Group 13 element in a reaction vessel provided with a conductive substrate, if necessary. And a method of forming a deposited film by supplying a source gas such as an O supply gas. At this time, the mixing ratio of the source gases, the gas pressure in the reaction vessel, the discharge power, and the temperature of the substrate can be appropriately set. Similarly, the optimum range of the pressure in the reaction vessel is appropriately selected according to the layer design. For example, 1.0 × 10 ⁻² Pa to 1.0 × 10 ³ Pa, preferably 5.0 × 10 ⁻² Pa to 5.0 × 10 ² Pa. Hereinafter, it is more preferably 1.0 × 10 ⁻¹ Pa or more and 1.0 × 10 ² Pa or less. Further, the optimum temperature of the substrate is appropriately selected according to the layer design, and is, for example, 150 ° C. or higher and 350 ° C. or lower, preferably 180 ° C. or higher and 330 ° C. or lower, more preferably 200 ° C. or higher and 300 ° C. or lower. In order to provide the maximum value in the thickness direction of the content rate of the group 13 element of the periodic table, a method of changing the amount of introduction of the source gas of the group 13 element containing the group 13 element may be used.

<Intermediate layer>
The intermediate layer provided in the surface region layer in the present invention is made of a non-single-crystal silicon nitride film having silicon atoms and nitrogen atoms as base materials, and has a maximum content value in the thickness direction of nitrogen atoms. I have it. Such an intermediate layer is formed between the first upper injection blocking layer (TBL-1) and the second upper injection blocking layer (TBL-2), the second upper injection blocking layer (TBL-2) and the third upper injection layer. By providing it between the injection blocking layers (TBL-3), in the surface region layer, the content of the group 13 element of the periodic table with respect to the total number of constituent atoms has two or more maximum values in the thickness direction of the surface region layer. And having a minimum value inevitably formed between the two maximum values, and further, together with the maximum value of the nitrogen atom content rate in the surface protective layer described later, the nitrogen atom content rate of the surface region layer A distribution having two or more maximum values in the thickness direction is formed.

  The shape of the maximum value of the nitrogen atom content may be a peak as shown in FIG. 10, FIG. 11 (a), (b), or as shown in FIG. 9 (a), (b). The maximum region may be used. The maximum value is preferably N / (Si + N) ≧ 30 atm% with respect to the total number of constituent atoms of the intermediate layer. The ratio (maximum value / minimum value) of the maximum value of nitrogen atoms in the thickness direction to the minimum value of nitrogen atoms in the upper injection blocking layer having a low nitrogen atom content is 1.10 or more. Preferably there is. However, nitrogen atoms that have a maximum value in the thickness direction and are contained in a non-uniform distribution are uniformly contained in a uniform distribution in the plane parallel to the surface of the substrate. It is preferable from the point of aiming at making it.

  It is preferable from the viewpoint of the effect of suppressing image defects that the maximum value of such nitrogen atoms on the photoconductive layer side and the minimum value between the maximum values of adjacent nitrogen atoms are at a distance of 40 nm to 300 nm.

  FIGS. 14A to 14D show the local maximum value on the photoconductive layer side and the two local maximums among the two adjacent local maximum values in the thickness direction of the nitrogen atom content rate relative to the total number of constituent atoms in the surface region layer. The minimum distance between values is shown schematically.

  The intermediate layer can contain oxygen and Group 13 elements of the periodic table as necessary. Nitrogen atoms or oxygen atoms contained in the intermediate layer are preferably contained in each intermediate layer with an average content of 10 atm% to 90 atm% with respect to the total number of constituent atoms from the viewpoint of sensitivity characteristics and electrical characteristics. . More preferably, it is 15 atm% or more and 85 atm% or less, More preferably, it is 20 atm% or more and 80 atm% or less. The oxygen atoms contained in the intermediate layer may be uniformly distributed in the layer, or may be unevenly distributed in the layer thickness direction. However, in any case, it is preferable that the content is evenly distributed in a plane parallel to the surface of the substrate from the point of achieving uniform characteristics in the plane.

  The thickness of the intermediate layer 106 is also related to the layer thickness of the upper injection blocking layer. The thickness of the intermediate layer is selected so that the distance between the maximum values of the group 13 element content of the periodic table in the adjacent upper injection blocking layer is 100 nm or more and 1000 nm or less. More preferable from the viewpoint of residual potential and sensitivity.

  Such an intermediate layer can be formed by the same method as that for the upper injection blocking layer, that is, the plasma CVD method. In the formation of the intermediate layer by the plasma CVD method, the raw material gas mixing ratio, the gas pressure in the reaction vessel, the discharge power, and the temperature of the substrate can be appropriately set. Similarly, the pressure in the reaction vessel can be appropriately selected within the optimum range according to the layer design, and the maximum value of the nitrogen atom content can also be formed by changing the introduction amount of the source gas containing nitrogen atoms. Can do.

<Surface protective layer>
The surface protective layer 108 provided in the surface region layer in the present invention preferably has a free surface and is made of a non-single-crystal silicon nitride film having silicon atoms and nitrogen atoms as base materials. The surface protective layer has one maximum value of the content rate in the thickness direction of nitrogen atoms, the content rate of the Group 13 element of the periodic table is low, and the photoreceptor has moisture resistance, continuous repeated use characteristics, electrical pressure resistance, Use environment characteristics and durability. About the maximum value in the thickness direction of the nitrogen atom content rate, its shape, the maximum value, the relationship between the minimum value of the nitrogen atom content in the upper injection blocking layer, the average content of nitrogen atoms, etc. It is the same.

  Further, the surface protective layer may contain oxygen atoms, hydrogen atoms, halogen atoms and the like as necessary. Hydrogen atoms and halogen atoms are bonded to dangling bonds of constituent atoms such as silicon, thereby improving the layer quality, particularly the photoconductivity and charge retention characteristics. From such a viewpoint, the content of hydrogen atoms is preferably 30 atm% or more and 70 atm% or less, more preferably 35 atm% or more and 65 atm% or less, further preferably 40 atm% or more and 60 atm% or less with respect to the total amount of constituent atoms. . As the halogen, for example, the fluorine atom content can be, for example, 0.01 atm% or more and 15 atm% or less, preferably 0.1 atm% or more and 10 atm% or less, more preferably 0.6 atm% or more and 4 atm% or less. .

  The layer thickness of the surface protective layer can be, for example, from 10 nm to 3000 nm, preferably from 50 nm to 2000 nm, and more preferably from 100 nm to 1000 nm. When the layer thickness is 10 nm or more, the surface protective layer 108 is not lost due to wear or the like during use of the photoreceptor, and when it is 3000 nm or less, the electrophotographic characteristics that suppress the increase in residual potential are maintained.

Such a surface protective layer can be formed by a plasma CVD method or the like. The surface protective layer can be formed by such a plasma CVD method by appropriately setting the temperature of the substrate and the gas pressure in the reaction vessel as desired. Can be done. The substrate temperature (Ts) is appropriately selected in the optimum range according to the layer design, but is preferably 150 ° C or higher and 350 ° C or lower, more preferably 180 ° C or higher and 330 ° C or lower, and further preferably 200 ° C or higher and 300 ° C or lower. . Similarly, the optimum range of the pressure in the reaction vessel is appropriately selected according to the layer design, but can be, for example, 1.0 × 10 ⁻² Pa or more and 1.0 × 10 ³ Pa or less, preferably 5.0 × 10 ⁻² Pa or more. 5.0 × 10 ² Pa or less, more preferably 1.0 × 10 ⁻¹ Pa or more and 1.0 × 10 ² Pa or less. The above-mentioned ranges can be mentioned as the desirable numerical ranges of the substrate temperature and gas pressure for forming the surface protective layer, but these conditions are not independently determined, and a photoreceptor having desired characteristics is formed. It is preferable to determine an optimum value based on mutual and organic relations.

  In the surface region layer having such a layer structure, the average concentration (atm%) of nitrogen atoms is preferably 30 atm% ≦ N / (Si + N) ≦ 70 atm% from the viewpoint of sensitivity.

  Further, the content ratio of oxygen atoms and / or fluorine atoms with respect to the total number of constituent atoms in the surface region layer has at least one maximum value in the thickness direction of the film in order to improve image quality and potential characteristics. More preferred.

  In addition, the content rate of each element such as oxygen, nitrogen, silicon, periodic table group 13 element, hydrogen or halogen described in this specification is measured by secondary ion mass spectrometry (SIMS), and the first Oxygen, nitrogen, silicon, group 13 elements of the periodic table for the total amount of atoms constituting the upper injection blocking layer (TBL-1), the intermediate layer, the second upper injection blocking layer (TBL-2), the surface protective layer, etc. This is a value obtained by calculating the ratio of hydrogen and halogen atoms.

<Substrate>
The substrate used in the present invention may be either a substrate made of a conductive material or a substrate in which a conductive treatment is performed on the surface on which at least the light-receiving layer that is electrically insulating is formed.

  Examples of the material for the conductive substrate include metals such as Al, Cr, Mo, In, Nb, Te, V, Ti, Pd, and Fe, and alloys thereof such as stainless steel.

Examples of the material for the electrically insulating substrate include films or sheets of synthetic resins such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, and polyamide, glass, and ceramic.
When an electrically insulating material is used for the substrate, it is necessary that at least the surface of the substrate on which the light receiving layer is formed be subjected to a conductive treatment.

  The shape of the substrate may be a smooth surface or a cylindrical surface with an uneven surface or an endless belt shape. The thickness is appropriately determined so that a desired light receiving member can be formed. When flexibility as a light receiving member is required, such as an endless belt-like substrate, the substrate can be made as thin as possible within the range in which the function as a substrate can be sufficiently exhibited. For handling, the thickness is usually 10 μm or more from the viewpoint of mechanical strength.

<Photoconductive layer>
In order to form a photoconductive layer on a substrate by, for example, a glow discharge method, a desired raw material is introduced in a gas state into a reaction vessel in which the inside can be decompressed, a glow discharge is generated in the reaction vessel, and a predetermined position is set in advance. A layer made of a-Si: H, X is formed on a predetermined substrate placed on the substrate. The raw material gas includes a raw material gas for supplying Si that can supply silicon atoms (Si), a raw material gas for supplying H that can supply hydrogen atoms (H), and halogen atoms (X) as necessary. A source gas for supplying X that can be supplied can be used.

  Hydrogen atoms in the photoconductive layer, and halogen atoms added as needed, have the function of compensating dangling bonds of silicon atoms and improving the layer quality, especially the photoconductivity and charge retention characteristics. ing.

  Although there is no restriction | limiting in particular in content of a hydrogen atom, It is preferable to set it as 10-40 atomic% with respect to the sum of a silicon atom and a hydrogen atom. Also, the distribution shape is preferably adjusted as appropriate, such as changing the content in accordance with the wavelength of the exposure system. In particular, it is known that when the content of hydrogen atoms or halogen atoms is increased to some extent, the optical band gap increases and the sensitivity peak shifts to the short wavelength side. Such an expansion of the optical band gap is preferable when short-wavelength exposure is used, and in that case, it is preferably 15% or more with respect to the sum of silicon and hydrogen atoms.

As a substance that can be a gas for supplying Si, silicon hydrides (silanes) in a gas state such as SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ , Si ₄ H ₁₀ , or the like that can be gasified are effectively used. Further, SiH ₄ and Si ₂ H ₆ are preferable from the viewpoints of easy handling during layer production, good Si supply efficiency, and the like. In addition, each gas may mix not only single type but multiple types by predetermined | prescribed mixing ratio.

In consideration of the controllability of film physical properties and the convenience of gas supply, these gases are further mixed with a desired amount of one or more gases selected from silicon compounds containing H2, He and hydrogen atoms. Layers can also be formed. Specific examples of source gases for supplying halogen atoms include fluorine gas (F ₂ ), BrF, ClF, ClF ₃ , BrF ₃ , BrF ₅ , IF ₃ , IF _{7 and} other interhalogen compounds, SiF ₄ , Si Silicon fluoride such as ₂ F ₆ can be mentioned as a preferable one.

  In order to control the amount of the halogen element contained in the photoconductive layer, for example, the temperature of the substrate, the amount of the raw material gas used to contain the halogen element introduced into the reaction vessel, the pressure in the discharge space, What is necessary is just to control discharge electric power etc.

  In addition, the photoconductive layer preferably contains atoms for controlling conductivity in a negative uniform distribution state in the layer thickness direction of the photoconductive layer. This is effective for improving the charging performance, reducing the optical memory effect, and improving the sensitivity by adjusting the carrier running property of the photoconductive layer or compensating to balance the running property at a high order. is there.

  The content of atoms for controlling conductivity is not particularly limited, but generally 0.05 to 5 atom ppm is desirable. Further, in a range where light reaches, control can be performed so as not to substantially contain atoms that control conductivity (no positive addition is performed).

  This conductivity control atom may contain the area | region which changes continuously or stepwise in the film thickness direction, and may contain the fixed area | region.

  Examples of the atoms that control conductivity include so-called impurities in the semiconductor field, and atoms belonging to Group 13 of the periodic table (also abbreviated as Group 13 atoms) or atoms belonging to Group 15 of the periodic table (Group No. 1). (Also abbreviated as group 15 atom).

  Specific examples of Group 13 atoms include boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl), and B, Al, and Ga are particularly preferable. .

Specifically, as such raw material for introducing Group 13 atoms, for introducing boron atoms, B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B ₆ H _{10 are used.} Borohydrides such as B ₆ H ₁₂ and B ₆ H ₁₄ , boron halides such as BF ₃ , BCl ₃ and BBr ₃ . In addition, AlCl ₃ , GaCl ₃ , Ga (CH ₃ ) ₃ , InCl ₃ and TlCl ₃ can also be mentioned.

  Specific examples of the Group 15 atom include nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and P, As, and Sb are particularly preferable.

Effectively used as a raw material for introducing Group 15 atoms are phosphorus hydrides such as PH ₃ and P ₂ H ₄ , PH ₄ I, PF ₃ , PF ₅ , PCl ₅ for introducing phosphorus atoms. , Phosphorus halides such as PBr ₃ , PBr ₅ and PI ₃ . In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsBr ₃ , AsF ₅ , SbH ₃ , SbF ₃ , SbF ₅ , SbCl ₃ , SbCl ₅ , BiH ₃ , BiCl _3, and BiBr ₃ are also used as source gases for introducing Group 15 atoms. It can be listed as effective.

Further, the atom introduction source gas for controlling the conductivity may be diluted with H ₂ and / or He if necessary.

  The layer thickness of the photoconductive layer is appropriately determined as desired from the viewpoint of obtaining desired electrophotographic characteristics and economic effects, and is preferably 5 to 50 μm, more preferably 10 to 45 μm, More preferably, it is 20-40 micrometers. When the layer thickness is 5 μm or more, electrophotographic characteristics such as practically sufficient charging ability and sensitivity can be obtained. When the layer thickness is 50 μm or less, the photoconductive layer preparation time is prolonged and the manufacturing cost does not increase. .

  In order to form a photoconductive layer having desired film characteristics, the mixing ratio between the gas for supplying Si and the gas for adding halogen and the dilution gas, the gas pressure in the reaction vessel, the discharge power, and the substrate temperature are appropriately set. Is desirable.

The flow rate of H ₂ and / or He used as the dilution gas is appropriately selected according to the layer design, but is preferably 3 to 30 times that of the Si supply gas, and preferably 4 to 15 times. More preferably, it is more preferably controlled within a range of 5 to 10 times. Similarly, the optimum range of the gas pressure in the reaction vessel is appropriately selected according to the layer design, but it is preferably 1 × 10 ⁻² to 1 × 10 ³ Pa, preferably 5 × 10 ^{−2 to} 5 × 10 ² Pa. It is more preferable that it is 1 × 10 ⁻¹ to 2 × 10 ² Pa.

  Similarly, the optimum range of the discharge power is also selected according to the layer design, but the ratio of the discharge power (W) to the flow rate of the gas for supplying Si (mL / min (normal)) is set to 0.5-8. It is preferable to set to the range, and it is more preferable to set to the range of 2-6.

  Furthermore, the optimum range of the substrate temperature is appropriately selected according to the layer design, but it is preferably set in the range of 200 to 350 ° C, more preferably in the range of 210 to 330 ° C, and optimally. Is more preferably set in the range of 220 to 300 ° C.

  Although the above-mentioned ranges are mentioned as the desirable numerical ranges of the substrate temperature and gas pressure for forming the photoconductive layer, the conditions are usually not independently determined separately, and a light-receiving member having desired characteristics is selected. It is preferable to determine an optimum value based on mutual and organic relations to be formed.

<Lower injection blocking layer>
In the present invention, as shown in FIG. 1, it is effective to provide a lower injection blocking layer 104 having a function of blocking charge injection from the substrate 101 side as an upper layer of the conductive substrate 101. The lower injection blocking layer 104 has a function of blocking charge injection from the substrate 101 side to the photoconductive layer 102 side when the photosensitive layer is subjected to a charging process having a constant polarity on its free surface.

  The lower injection blocking layer 104 contains a relatively large amount of impurities that control conductivity using silicon atoms as a base material compared to the photoconductive layer 102. As the impurity element contained in the lower injection blocking layer 104, a Group 15 element of the periodic table can be used. In the present invention, the content ratio of the impurity element contained in the lower injection blocking layer 104 is appropriately determined as desired so that the object of the present invention can be effectively achieved, but preferably in the lower injection blocking layer. It is 10 atomic ppm or more and 10000 atomic ppm or less with respect to the total number of constituent atoms. It is more preferably 50 atom ppm or more and 7000 atom ppm or less, and further preferably 100 atom ppm or more and 5000 atom ppm or less.

  Furthermore, the lower injection blocking layer 104 can contain nitrogen and oxygen to improve the adhesion between the lower injection blocking layer 104 and the substrate 101.

  The charge injection blocking ability can also be obtained by optimally containing nitrogen and oxygen even if the lower injection blocking layer 104 does not contain an impurity element. Specifically, the sum of nitrogen atoms and oxygen atoms contained in the entire layer region of the lower injection blocking layer 104 is 0.1 atomic% or more and 40 atomic% with respect to the total amount of constituent atoms in the lower injection blocking layer. By making the following, excellent charge injection stopping ability can be obtained. In this case, the sum of nitrogen atoms and oxygen atoms contained in the entire layer region of the lower injection blocking layer 104 is 1.2 atomic% or more and 20 atomic% or less with respect to the total number of constituent atoms in the lower injection blocking layer. More preferably.

  The lower injection blocking layer 104 preferably contains hydrogen atoms. In this case, the contained hydrogen atoms compensate for dangling bonds existing in the layer and have an effect of improving the film quality. The content of hydrogen atoms contained in the lower injection blocking layer 105 is preferably 1 atom% or more and 50 atom% or less, and preferably 5 atom% or more and 40 atom% or less with respect to the total amount of constituent atoms in the lower injection blocking layer 105. More preferably, it is more preferably 10 atomic% or more and 30 atomic% or less.

  In the present invention, the thickness of the lower injection blocking layer 104 is preferably 100 nm or more and 5000 nm or less, more preferably 300 nm or more and 4000 nm or less, and more preferably 500 nm or more and 3000 nm or less in view of obtaining desired electrophotographic characteristics and economic effects. More preferably. By setting the layer thickness to 100 nm or more and 5000 nm or less, the charge injection ability from the substrate 101 becomes sufficient, and sufficient charging ability can be obtained and improvement in electrophotographic characteristics can be expected. Does not occur.

  In order to form the lower injection blocking layer 104, it is necessary to appropriately set the gas pressure in the reaction vessel, the discharge power, and the temperature of the substrate. The optimum range of the conductive substrate temperature (Ts) is appropriately selected according to the layer design, but is preferably 150 ° C or higher and 350 ° C or lower, more preferably 180 ° C or higher and 330 ° C or lower, and 200 ° C or higher and 300 ° C or lower. Is more preferable.

Similarly, the optimum range of the pressure in the reaction vessel is appropriately selected according to the layer design, but 1 × 10 ⁻² Pa. It is preferably 1 × 10 ³ Pa or less, more preferably 5 × 10 ⁻² Pa or more and 5 × 10 ² Pa or less, and further preferably 1 × 10 ⁻¹ Pa or more and 1 × 10 ² or less.

<Electrophotographic photoconductor manufacturing apparatus>
Next, an apparatus and a film forming method for producing the photosensitive layer of the present invention will be described in detail.

  FIG. 2 is a schematic configuration diagram showing an example of an apparatus for manufacturing an electrophotographic photosensitive member by a high-frequency plasma CVD method (also abbreviated as RF-PCVD) using an RF band as a power supply frequency. The configuration of the manufacturing apparatus shown in FIG. 2 is as follows.

  This apparatus is roughly divided into a deposition apparatus (2100), a source gas supply apparatus (2200), and an exhaust apparatus (not shown) for reducing the pressure in the reaction vessel (2111). A cylindrical substrate (2112), a substrate heating heater (2113), a source gas introduction pipe (2114) are installed in a reaction vessel (2111) in the deposition apparatus (2100), and a high-frequency matching box (2115) is connected. Has been.

The source gas supply device (2200) includes cylinders (2221 to 2226) and valves (2231 to 2236, 2241 to 2246) of source gases such as SiH ₄ , GeH ₄ , H ₂ , CH ₄ , B ₂ H ₆ , and PH ₃ . 2251 to 2256) and a mass flow controller (2211 to 2216), each gas cylinder is connected to a gas introduction pipe (2114) in the reaction vessel (2111) via an auxiliary valve (2260).

  Formation of the deposited film using this apparatus can be performed as follows, for example.

  First, the cylindrical substrate (2112) is installed in the reaction vessel (2111), and the inside of the reaction vessel (2111) is evacuated by an unillustrated exhaust device (for example, a vacuum pump). Subsequently, the temperature of the cylindrical substrate (2112) is controlled to a predetermined temperature of 150 ° C. to 350 ° C. by the substrate heating heater (2113).

  In order to flow the source gas for forming the deposited film into the reaction vessel (2111), confirm that the gas cylinder valve (2231 to 2236) and the reaction vessel leak valve (2117) are closed, and the gas flow After confirming that the valve (2241 to 2246), the outflow valve (2251 to 2256), and the auxiliary valve (2260) are opened, first the main valve (2118) is opened and the reaction vessel (2111) and the raw material gas pipe are opened. (2116) is exhausted.

  Next, when the reading of the vacuum gauge (2119) becomes about 0.1 Pa or less, the auxiliary valve (2260) and the gas outflow valves (2251 to 2256) are closed. Thereafter, each gas is introduced from the gas cylinder (2221 to 2226) by opening the source gas cylinder valve (2231 to 2236), and each gas pressure is adjusted to 0.2 MPa by the pressure regulator (2261 to 2266). Next, the gas inflow valves (2241 to 2246) are gradually opened to introduce each gas into the mass flow controller (2211 to 2216).

  After the preparation for film formation is completed as described above, each layer is formed according to the following procedure.

When the cylindrical base body (2112) reaches a predetermined temperature, necessary ones of the outflow valves (2251 to 2256) and the auxiliary valve (2260) are gradually opened, and a predetermined gas is supplied from the gas cylinders (2221 to 2226). It introduce | transduces in a reaction container (2111) through a source gas introduction pipe | tube (2114). Next, it adjusts so that each source gas may become predetermined | prescribed flow volume by a massflow controller (2211-2216). At that time, the opening of the main valve (2118) is adjusted while looking at the vacuum gauge (2119) so that the pressure in the reaction vessel (2111) becomes a predetermined pressure of 1 × 10 ² Pa or less. When the internal pressure is stabilized, an RF power source (not shown) having a frequency of 13.56 MHz is set to a desired power, and RF power is introduced into the reaction vessel (2111) through the high-frequency matching box (2115) to cause glow discharge. Let The source gas introduced into the reaction vessel is decomposed by this discharge energy, and a deposited film containing a predetermined silicon as a main component is formed on the cylindrical substrate (2112). After the formation of the desired film thickness, the supply of RF power is stopped, the outflow valve is closed, the gas flow into the reaction vessel is stopped, and the formation of the deposited film is completed.

By repeating the same operation a plurality of times, a desired multilayered light-receiving layer is formed.
It goes without saying that all of the outflow valves other than the necessary gas are closed when forming each layer, and each gas flows from the outflow valves (2251 to 2256) into the reaction vessel in the reaction vessel (2111). In order to avoid remaining in the pipe leading to (2111), the outflow valve (2251 to 2256) is closed, the auxiliary valve (2260) is opened, the main valve (2118) is fully opened, and the inside of the system is once subjected to high vacuum. If necessary, perform the exhausting operation.

  In order to make the film formation uniform, it is also effective to rotate the cylindrical substrate (2112) at a predetermined speed by a driving device (not shown) during the layer formation.

  Furthermore, the above gas species and valve operation can be modified according to the production conditions of each layer.

  The heating method of the substrate may be any heating element that is vacuum specification. More specifically, the heating resistance of a sheathed heater, an electric resistance heating element such as a plate heater, a ceramic heater, a halogen lamp, an infrared lamp, etc. Radiant lamp heating elements, heating elements by heat exchange means using liquid, gas or the like as a heating medium, and the like can be mentioned. As the surface material of the heating means, metals such as stainless steel, nickel, aluminum, and copper, ceramics, heat resistant polymer resin, and the like can be used.

  In addition to this, there is used a method in which a container dedicated to heating is provided in addition to the reaction container, and after heating, the substrate is transported in a vacuum in the reaction container.

<Electrophotographic device>
FIG. 3 is a schematic diagram of an image forming apparatus that can suitably use the electrophotographic photosensitive member of the present invention.

  FIG. 3 shows an example of a color image forming apparatus (a copying machine or a laser beam printer) using an electrophotographic process in which transfer is performed using an intermediate transfer belt 305 made of a film-like dielectric belt.

  This image forming apparatus is a repetitively used electrophotographic photosensitive member which is a first image carrier on which an electrostatic latent image is formed on a surface and toner is attached to the electrostatic latent image to form a toner image. It has a rotating drum type photosensitive drum 301 composed of a body. Around the photosensitive drum 301, a primary charger 302 that uniformly charges the surface of the photosensitive drum 301 to a predetermined polarity and potential, and image exposure 303 is performed on the charged surface of the photosensitive drum 301. An image exposure device (not shown) that forms an electrostatic latent image is disposed. In addition, a rotary second developing device 304b is disposed as a developing device for developing the toner by attaching toner onto the formed electrostatic latent image. The rotary type second developing device 304b includes a first developing device 304a for attaching black toner (B), a developing device for attaching yellow toner (Y), and a developing device for attaching magenta toner (M). And a developing device for attaching cyan toner (C). Further, after transferring the toner image to the intermediate transfer belt 305, a photoconductor cleaner 306 that cleans the surface of the photoconductor drum 301, and a static elimination exposure 307 that performs static elimination of the photoconductor drum 301 are provided.

  The intermediate transfer belt 305 is disposed so as to be driven to the photosensitive drum 301 via the contact nip portion, and in order to transfer the toner image formed on the photosensitive drum 301 to the intermediate transfer belt 305. Primary transfer roller 308 is provided. A bias power supply (not shown) for applying a primary transfer bias for transferring the toner image on the photosensitive drum 301 to the intermediate transfer belt 305 is connected to the primary transfer roller 308. Around the intermediate transfer belt 305, a secondary transfer roller 309 for further transferring the toner image transferred to the intermediate transfer belt 305 to the recording material 313 is provided so as to be in contact with the lower surface portion of the intermediate transfer belt 305. ing. The secondary transfer roller 309 is connected to a bias power source that applies a secondary transfer bias for transferring the toner image on the intermediate transfer belt 305 to the recording material 313. Further, an intermediate transfer belt cleaner 310 is provided for cleaning the transfer residual toner remaining on the surface of the intermediate transfer belt 305 after the toner image on the intermediate transfer belt 305 is transferred to the recording material 313.

  The image forming apparatus also includes a paper feed cassette 314 that holds a plurality of recording materials 313 on which an image is formed, and a recording material 313 that contacts the intermediate transfer belt 305 and the secondary transfer roller 309 from the paper feed cassette 314. And a transport mechanism for transporting through the nip portion. A fixing device 315 for fixing the toner image transferred onto the recording material 313 on the recording material 313 is disposed on the conveyance path of the recording material 313.

  As the primary charger 302, a magnetic brush type charger or the like is used. As an image exposure apparatus, a color separation / imaging exposure optical system for a color original image, a scanning exposure system using a laser scanner that outputs a laser beam modulated in accordance with a time-series electric digital pixel signal of image information, and the like are used. It is done.

  Next, the operation of this image forming apparatus will be described.

  First, as indicated by an arrow in FIG. 3, the photosensitive drum 301 is rotationally driven in the clockwise direction at a predetermined peripheral speed (process speed), and the intermediate transfer belt 305 is the same as the photosensitive drum 301 in the counterclockwise direction. It is rotationally driven at a peripheral speed.

  The photosensitive drum 301 is uniformly charged to a predetermined polarity and potential by the primary charger 302 in the course of rotation, and then subjected to image exposure 303, whereby the surface of the photosensitive drum 301 has a target surface. An electrostatic latent image corresponding to a first color component image (for example, a magenta component image) of the color image is formed. Next, the second developing device rotates to set the developing device to which the magenta toner (M) is adhered at a predetermined position, and the electrostatic latent image is developed with the first color magenta toner (M). At this time, the first developing device 304a and the operation are off, and the first developing device 304a does not act on the photosensitive drum 301 and does not affect the first color magenta toner image.

  In this manner, the first color magenta toner image formed and supported on the photosensitive drum 301 passes through the nip portion between the photosensitive drum 301 and the intermediate transfer belt 305, and the primary transfer bias is bias power source ( The intermediate transfer is successively performed on the outer peripheral surface of the intermediate transfer belt 305 by an electric field formed by being applied to the primary transfer roller 308 from the unillustrated).

  The surface of the photosensitive drum 301 after the first color magenta toner image has been transferred to the intermediate transfer belt 305 is cleaned by a photosensitive cleaner 306. Next, a second color toner image (for example, a cyan toner image) is formed on the cleaned surface of the photosensitive drum 301 in the same manner as the first color toner image, and the second color toner image is formed. Are superimposed and transferred onto the surface of the intermediate transfer belt 305 onto which the first color toner image has been transferred. Similarly, a third color toner image (for example, a yellow toner image) and a fourth color toner image (for example, a black toner image) are sequentially superimposed and transferred onto the intermediate transfer belt 305, and a combined color corresponding to the target color image. A toner image is formed.

  Next, the recording material 313 is fed from the paper feed cassette 314 to the contact nip portion between the intermediate transfer belt 305 and the secondary transfer roller 309 at a predetermined timing. The secondary transfer roller 309 is brought into contact with the intermediate transfer belt 305, and a secondary transfer bias is applied from the bias power source to the secondary transfer roller 309, so that the composite color toner image superimposed and transferred onto the intermediate transfer belt 305 is formed. Then, it is transferred to a recording material 313 which is a second image carrier. After the transfer of the toner image onto the recording material 313 is completed, the transfer residual toner on the intermediate transfer belt 305 is cleaned by the intermediate transfer belt cleaner 310. The recording material 313 to which the toner image has been transferred is guided to a fixing device 315 where the toner image is heated and fixed on the recording material 313.

  In the operation of the image forming apparatus, when the first to fourth color toner images are sequentially transferred from the photosensitive drum 301 to the intermediate transfer belt 305, the secondary transfer roller 309 and the intermediate transfer belt cleaner 310 are moved to the intermediate transfer belt 305. You may make it leave | separate from.

  An electrophotographic color image forming apparatus using such an intermediate transfer belt has the following characteristics.

  First, there is little color misregistration that shifts the formation positions of the toner images of the respective colors during superposition. Further, as shown in FIG. 3, the toner image can be transferred from the intermediate transfer belt 305 without any processing and control (for example, gripping, adsorbing, giving a curvature, etc.) to the recording material 313. Various kinds of recording materials 313 can be used. For example, various thicknesses from thin paper (40 g / m 2 paper) to thick paper (200 g / m 2 paper) can be selected and used as the recording material 313. In addition, recording materials 313 having various sizes can be used regardless of the width or the length. Furthermore, an envelope, a postcard, a label paper, or the like can be used as the recording material 313.

  In addition, the intermediate transfer belt 305 is excellent in flexibility and can freely set a nip with the photosensitive drum 301 or the recording material 313. Therefore, the intermediate transfer belt 305 has a high degree of design freedom and can easily optimize transfer efficiency. There are features such as.

  As described above, the image forming apparatus using the intermediate transfer belt 305 has various advantages.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited at all by these.

<Example 1>
Using the plasma CVD apparatus shown in FIG. 2, a deposited film is sequentially laminated on an aluminum cylinder (support) having a mirror finish with a diameter of 84 mm and a length of 381 mm under the conditions shown in Table 1 to form a lower injection blocking layer. A photoconductor comprising a photoconductive layer, a change layer, and a surface layer was produced. The lower injection blocking layer, the photoconductive layer, and the change layer were all manufactured under the conditions shown in Table 1 as common conditions. Regarding the surface layer, as shown in Table 2, the gas flow rate of SiH ₄ is 10 to 50 mL / min (normal), the gas flow rate of N ₂ is 20 to 1000 mL / min (normal), and the RF power is 150 to 300 W. It was made by changing the flow rate and electric energy conditions. Photoconductors 1-a to 1-h having different nitrogen atom concentrations in the surface layer were produced.

  The following evaluations were performed on the photoreceptors 1-a to 1-h thus manufactured.

For the evaluation of the electrophotographic characteristics, Canon's electrophotographic device iR C6800 is modified for use with a magnetic brush system for experiments, the charge polarity can be changed, and the image exposure system modified to the IAE system. did. At this time, evaluation was performed using two types of remodeling machines: a light source for image exposure modified to a blue light emitting semiconductor laser having an oscillation wavelength of 405 nm, and a light emitting semiconductor laser modified to 660 nm. The measurement results are shown in Table 2.
(1) Actual nitrogen atom concentration in the surface layer The analysis was performed by SIMS (secondary ion mass spectrometry, manufactured by CAMECA: IMS-4F).
(2) Surface layer thickness Measured with respect to 60 points of 10 points in the axial direction and 6 points in the circumferential direction by an interference thickness meter (MCPD-2000 manufactured by Otsuka Electronics Co., Ltd.), and the value of (maximum value)-(minimum value) The value divided by the average film thickness was defined as film thickness unevenness (unit%).

When the film thickness non-uniformity exceeds 30%, the non-uniformity in hardness and resistance increases, but there is no problem in practical use. Further, when the film thickness unevenness exceeds 40%, the hardness and resistance unevenness are also large, and a phenomenon of partial scraping on the streaks occurs in continuous use, which is not preferable.
(3) Transmissivity of 405 nm light The spectral sensitivity characteristic was evaluated by the reciprocal of the amount of light necessary to attenuate light from a constant dark part potential to a constant bright part potential. That is, the amount of potential attenuation per unit energy of light is defined as the spectral sensitivity with respect to the exposure wavelength, and the spectral sensitivity at each wavelength when the exposure wavelength is changed is measured. Evaluation was performed using numerical values normalized by the spectral sensitivity peak value. More specifically, in order to evaluate the transmittance of 405 nm light, the transmittance was evaluated based on the spectral sensitivity of 405 nm light.

  The spectral sensitivity here refers to the amount of surface potential attenuation per unit light quantity (unit area) when the surface of the photosensitive member is charged to a constant potential, for example, 450 V, and then irradiated with light of various wavelengths. cm2 / μJ). FIG. 5 is a plot of values normalized by the wavelength on the horizontal axis and the maximum value of potential attenuation on the vertical axis.

  Here, the measurement of the surface potential decay was performed in the same manner as the method of Kajita et al. (Journal of Electrophotographic Society, Vol. 22, No. 1, 1983). In order to reproduce the behavior of the surface potential decay, in order to reproduce the behavior in the copying machine, a transparent electrode such as an ITO electrode is brought into close contact with the surface of the photoconductor, and exposure and voltage application are performed by imitating the sequence in the copying machine, and the surface potential is measured. Measure changes. When measuring the surface potential, it is preferable that the photoreceptor is regarded as a capacitor, and it is possible to obtain information on the chargeability of the photoreceptor by applying a potential in series with a known capacitance. In the method of Hamada et al., A method of sandwiching a transparent insulating film between a photoreceptor and an ITO electrode is used, but a fixed capacitor may be used by devising an electric circuit.

  First, a static elimination light (for example, 50 mW / cm 2) is irradiated for a certain time (for example, 0.1 second), and after a certain time (for example, 0.01 second), a voltage is applied (for example, about 20 msec) to charge the surface. After a certain period of time (about 0.1 to 0.5 seconds, for example, 0.25 seconds) after the voltage application is removed, the surface of the conductor connected to the ITO electrode is measured with an electrometer. This time corresponds to the timing at which the portion to which the potential of the photoreceptor is applied in the copying machine reaches the developing device, and therefore corresponds to the potential at the position of the developing device. Next, light of various wavelengths is exposed between voltage application and potential measurement in the same sequence (for example, 0.1 seconds after voltage application), and the potential at the timing corresponding to the position of the developer is measured in the same manner. The difference between the case where light is applied and the case where light is not applied is calculated. This corresponds to measuring the potential attenuation due to the exposure light at the position of the developing device.

The sensitivity of the electrophotographic photosensitive member of the present invention is preferably 300 V · cm ² / μJ or more, more preferably 400 V · cm ² / μJ or more, as the sensitivity obtained by the measurement method as described above.

  Further, FIG. 6 shows a graph plotting the correlation between the nitrogen atom concentration in the surface layer and the spectral sensitivity to light of 405 nm.

  As is clear from FIG. 6, there is a clear correlation between the nitrogen atom concentration and the spectral sensitivity to 405 nm light, and the spectral sensitivity to 405 nm light improves as the nitrogen atom concentration increases. That is, it can be seen that the adaptability to blue-emitting semiconductor laser light tends to improve.

  The sensitivity value required in the electrophotographic process depends on the performance of the laser element and the optical system to be used, and it is generally difficult to mention the absolute value. The produced photoreceptor 1-b was placed in an image forming apparatus for evaluation. After adjusting the charger so that the surface potential at the developing device position becomes −450 V (dark potential), 405 nm image exposure is performed, the light amount of the image exposure light source is adjusted, and the surface potential is −100 V (bright potential). The exposure amount at that time was used as the reference sensitivity.

  Other photoreceptors were similarly installed in an image forming apparatus for evaluation, and 405 nm image exposure was irradiated with reference sensitivity. If the potential at that time did not fall below −100 V, it was determined that the sensitivity was insufficient.

  Thus, as a result of various examinations by the present inventors regarding sensitivity, it is preferable that the index is normalized with the peak value of spectral sensitivity as shown in FIG. It is more preferable to have the above sensitivity. Therefore, in order to obtain such sensitivity, the nitrogen atom concentration in the surface layer is set to 30 atomic% or more, more preferably 35 atomic% or more. As a result, it has become clear from FIG. 6 that there is a further effect of having sensitivity to short-wavelength laser light around 405 nm, such as a blue-emitting semiconductor laser.

  On the other hand, as is clear from Table 2, it was found that the photoreceptor 1-g has large film thickness unevenness, and it is preferable that the nitrogen concentration is not too high when used as a surface layer. From such a viewpoint, it has been found that the nitrogen atom concentration in the surface layer is preferably 70 atom% or less, more preferably 60 atom% or less.

＜実施例２＞
図２に示したプラズマＣＶＤ装置を用い、図１に示した層構成となるように、直径８４ｍｍ、長さ３８１ｍｍの鏡面加工を施したアルミニウムシリンダー（支持体）上に、表３に示した条件で堆積膜を順次積層した。下部注入阻止層、光導電層、及び変化層、表面層からなる感光体を製作した。

<Example 2>
Using the plasma CVD apparatus shown in FIG. 2, on the aluminum cylinder (support) having a mirror finish of 84 mm in diameter and 381 mm in length so as to have the layer structure shown in FIG. The deposited films were sequentially stacked. A photoreceptor comprising a lower injection blocking layer, a photoconductive layer, a change layer, and a surface layer was produced.

  At this time, in the formation of the region after the maximum value formation of the change layer, the RF power is changed to make the change in composition of the change layer partially discontinuous, and the reflectance Max (%) and Min (%) are changed. The bodies 2-a to 2-h were produced. At this time, increasing the RF power tended to increase the nitrogen content.

  The photoreceptors 2-a to 2-h thus prepared were set in a machine in which the Canon electrophotographic apparatus iR C6800 was modified for experimentation, and a halftone image was subjected to durability of passing 1 million sheets, and the image density was Unevenness was evaluated. The above machine is modified by changing the charger to the magnetic brush method, changing the charging polarity to change, changing the image exposure method to the IAE method, and changing the light source for image exposure to a blue light emitting semiconductor laser with an oscillation wavelength of 405 nm. The optical system for image exposure was modified so that the drum surface irradiation spot diameter could be adjusted.

  The obtained results were determined based on the following criteria, with the density unevenness level of the initial image as a reference. The results are shown in Table 4.

○: The density unevenness level of the initial image is maintained and is very good level. Δ: The density unevenness is slightly worse than the density unevenness level of the initial image, but there is no practical problem. 0% ≦ Max (%) ≦ 20% and 0 ≦ (Max−
It was found that image density unevenness due to shaving can be reduced by satisfying (Min) / (100−Max) ≦ 0.15.

＜実施例３＞
図２に示したプラズマＣＶＤ装置を用い、図１に示した層構成となるように、直径８４ｍｍ、長さ３８１ｍｍの鏡面加工を施したアルミニウムシリンダー（支持体）上に、表５に示した条件で堆積膜を順次積層した。下部注入阻止層、光導電層、変化層、表面層からなる感光体を製作した。このとき、表５にあるように、変化層と表面層の形成途中でＢ₂Ｈ₆ガスを導入することで周期表第１３族元素のホウ素原子濃度が極大値を持つようにした。

<Example 3>
Using the plasma CVD apparatus shown in FIG. 2, on the aluminum cylinder (support) having a mirror finish of 84 mm in diameter and 381 mm in length so as to have the layer structure shown in FIG. The deposited films were sequentially stacked. A photoreceptor comprising a lower injection blocking layer, a photoconductive layer, a change layer, and a surface layer was produced. At this time, as shown in Table 5, B ₂ H ₆ gas was introduced during the formation of the change layer and the surface layer so that the boron atom concentration of the Group 13 element of the periodic table had a maximum value.

As a method for introducing the gas in the maximum value formation region in Table 5, a constant value of B ₂ H ₆ gas was introduced for a predetermined time. As a result, it was confirmed by SIMS measurement that the boron atom had a maximum value as shown in FIG.

Moreover, the maximum value of the periodic table group 13 element (boron atom) in this example was 5.3 × 10 ¹⁹ cm ³ and 1.1 × 10 ¹⁹ cm ³ from the photoconductive layer side. Moreover, the distance between the maximum values of the periodic table group 13 element (boron atom) was 240 nm.

Further, the amount of nitrogen atoms was 55 atomic% in terms of N / (Si + N).
Further, the minimum value (Min) and the maximum value (Max) of the reflectance (%) in the wavelength range of 350 nm to 680 nm are Min = 8% and Max = 15%, and 0% ≦ Max (%) ≦ 20%. And the relationship of 0 ≦ (Max−Min) / (100−Max) ≦ 0.15 is satisfied.

＜比較例１＞
図２に示したプラズマＣＶＤ装置を用い、図１に示した層構成となるように、直径８４ｍｍ、長さ３８１ｍｍの鏡面加工を施したアルミニウムシリンダー（支持体）上に、堆積膜を順次積層した。下部注入阻止層、光導電層、上部阻止層、表面層からなる感光体を製作した。この際、下部注入阻止層、光導電層までは、実施例１の表５と同様の条件で作製し、表６に示した条件で上部注入阻止層、表面層を作製した。上部注入阻止層中にＢ₂Ｈ₆ガスを導入する事で周期表第１３族元素のホウ素原子濃度が極大値を持つようにした。そのときの周期表第１３族元素（ホウ素原子）の極大値は、２．１×１０¹⁸ｃｍ³ であった.
なお、本比較例では、変化層を形成せず、更には表面層内に周期表第１３族元素の極大値を形成しなかった。

<Comparative Example 1>
Using the plasma CVD apparatus shown in FIG. 2, deposited films were sequentially laminated on an aluminum cylinder (support) having a mirror finish of 84 mm in diameter and 381 mm in length so as to have the layer structure shown in FIG. . A photoreceptor comprising a lower injection blocking layer, a photoconductive layer, an upper blocking layer, and a surface layer was produced. At this time, the lower injection blocking layer and the photoconductive layer were prepared under the same conditions as in Table 5 of Example 1, and the upper injection blocking layer and the surface layer were prepared under the conditions shown in Table 6. By introducing B ₂ H ₆ gas into the upper injection blocking layer, the boron atom concentration of the Group 13 element of the periodic table was made to have a maximum value. The maximum value of the periodic table group 13 element (boron atom) at that time was 2.1 × 10 ¹⁸ cm ³ .
In this comparative example, the change layer was not formed, and the maximum value of the Group 13 element of the periodic table was not formed in the surface layer.

  Further, the minimum value (Min) and the maximum value (Max) of the reflectance (%) in the wavelength range of 350 nm to 680 nm are Min = 8%, Max = 30%, 0% ≦ Max (%) ≦ 20% and The relationship 0 ≦ (Max−Min) / (100−Max) ≦ 0.15 is not satisfied.

実施例３、比較例１で得られた感光体を、前述の画像露光の光源を発振波長４０５ｎｍの青色発光半導体レーザーとした画像形成装置にセットし、以下に示す評価項目について評価を行った。
（１）解像度
パソコンで、２ポイントサイズ、及び、３ポイントサイズのアルファベット（Ａ〜Ｚ）、及び、複雑な漢字（電、驚など）を１２００ｄｐｉの解像度で配列したテストチャートを作成した。そのテストチャートをプリントアウトした画像によって感光体の解像度の評価
を行った。具体的には、出力画像をスキャナー（キヤノン製ＣａｎｏＳｃａｎ９９００Ｆ）を使って１６００ｄｐｉの解像度で読み取り、読み取った画像データとテストチャートの元データを比較した。テスト原稿の文字からのズレ部分（太り、細り）の面積を算出し、その数値によって感光体の解像度の評価を行った。得られた結果は、比較例１の感光体の値をリファレンス、即ち、１００％とした場合の相対評価でランク判定を行った。
◎：８０％未満で、リファレンスに比べて、非常に良いレベル
○：８０％以上、９５％未満で、リファレンスに比べて、良いレベル
△：ファレンスと同等レベル
（２）帯電能
作製した電子写真感光体を電子写真装置に設置して帯電を行ない、現像器位置に設置した表面電位計により電子写真感光体の暗部表面電位を測定し帯電能とした。このとき、比較のために帯電条件（帯電器へのＤＣ印加電圧、重畳ＡＣ振幅、周波数など）は一定とした。得られた結果は、比較例１の感光体をリファレンスとし、以下に示す判断基準によってランク判定を行った。
◎：リファレンスに比べて１０％以上向上し、非常に良いレベル
○：リファレンスに比べて５％以上向上し、良いレベル
△：ファレンスと同等レベル
（３）残留電位
作製した電子写真感光体を、現像器位置における表面電位が−４５０Ｖ（暗電位）になるように帯電器を調整した後、像露光光源の光量を最大になるように調整し、像露光を照射した。現像器位置に設置した表面電位計により電子写真感光体の表面電位を測定し残留電位とした。得られた結果は、比較例１の感光体をリファレンスとし、以下に示す判断基準によってランク判定を行った。
◎：リファレンスに比べて１０％以上向上し、非常に良いレベル
○：リファレンスに比べて５％以上向上し、良いレベル
△：ファレンスと同等レベル
（４）感度
作製した電子写真感光体を、現像器位置における表面電位が−４５０Ｖ（暗電位）になるように帯電器を調整した後、像露光を照射した。像露光光源の光量を調整して、表面電位が−１００Ｖ（明電位）となるようにし、そのときの露光量を感度とした。得られた結果は、比較例１の感光体をリファレンスとし、以下に示す判断基準によってランク判定を行った。
◎：リファレンスに比べて１０％以上向上し、非常に良いレベル
○：リファレンスに比べて５％以上向上し、良いレベル
△：ファレンスと同等レベル
（５）電位ムラ
作製した電子写真感光体を、現像器位置における暗部電位が−４５０Ｖになるように帯電器を調整し、現像器位置における明部電位が−１００Ｖになるように像露光光源の光量を調整した状態において、暗部電位と明部電位の面内分布を測定した。その最大値と最小値の差を電位ムラとした。得られた結果は、比較例１の感光体をリファレンスとし、以下に示す判断基準によってランク判定を行った。
◎：リファレンスに比べて１０％以上向上し、非常に良いレベル
○：リファレンスに比べて５％以上向上し、良いレベル
△：ファレンスと同等レベル
（６）光メモリ
光メモリ電位は、現像器位置における暗部電位が−４５０Ｖになるように帯電器を調整し、現像器位置における明部電位が−１００Ｖになるように像露光光源の光量を調整した状態で感光体の表面電位を電位センサーで測定して求めた。非像露光状態での表面電位と一旦像露光した後に再度帯電した時との電位差を測定し、光メモリとした。得られた結果は、比較例１の感光体をリファレンスとし、以下に示す判断基準によってランク判定を行った。
◎：リファレンスに比べて１０％以上向上し、非常に良いレベル
○：リファレンスに比べて５％以上向上し、良いレベル
△：ファレンスと同等レベル
（７）４０５ｎｍ光の透過性
分光感度特性は、一定暗部電位から一定明部電位まで光減衰させるのに必要な光量の逆数によって評価した。即ち、光の単位エネルギー量当たりの電位減衰量をその露光波長に対する分光感度とし、露光波長を変化させた時の各波長における分光感度を測定して、分光感度が最大になる波長の分光感度（分光感度のピーク値）によって規格化した数値によって評価を行った。より具体的には、４０５ｎｍ光の透過性を評価するために、４０５ｎｍ光の分光感度によって透過性の評価を行った。
（８）クリーニング性
クリーニング性は、クリーニング残トナーが発生し始めるクリーニングブレード圧力によって評価を行った。具体的には、Ａ４コピー紙１０００枚の通紙耐久を行った後の、感光体表面を観察し、クリーニング残トナーの有無を、クリーニングブレード圧力を徐々に低くしながら繰り返し観察して、クリーニング残トナーが発生し始めるクリーニングブレード圧力を調べた。得られた結果は、比較例１の感光体の値をリファレンス、即ち、１００％とした場合の相対評価でランク付けを行った。クリーニング残トナーが発生し始めるクリーニングブレード圧力は、低い方がクリーニングのラチチュードが広く、クリーニング性に優れると解釈することができる。
◎：８０％未満で、リファレンスに比べて、非常に良いレベル
○：８０％以上、９５％未満で、リファレンスに比べて、良いレベル
△：ファレンスと同等レベル
得られた結果は、比較例１の結果と共に表７に示す。

The photoreceptors obtained in Example 3 and Comparative Example 1 were set in an image forming apparatus in which the light source for image exposure described above was a blue light emitting semiconductor laser having an oscillation wavelength of 405 nm, and the following evaluation items were evaluated.
(1) Resolution Using a personal computer, a test chart in which alphabets (A to Z) of 2 points and 3 points and complex Chinese characters (Den, Surprise, etc.) were arranged at a resolution of 1200 dpi was created. The resolution of the photoconductor was evaluated by an image printed out of the test chart. Specifically, the output image was read at a resolution of 1600 dpi using a scanner (Canon Scan 9900F manufactured by Canon), and the read image data was compared with the original data of the test chart. The area of the misaligned portion (thickness, thinness) from the characters of the test document was calculated, and the resolution of the photoconductor was evaluated based on the numerical value. As for the obtained results, rank determination was performed by relative evaluation when the value of the photoconductor of Comparative Example 1 was set as a reference, that is, 100%.
◎: Less than 80%, very good level compared to reference ○: 80% or more, less than 95%, better level than reference Δ: Level equivalent to reference (2) Charging ability The body was placed in an electrophotographic apparatus to be charged, and the surface potential meter of the electrophotographic photoreceptor was measured with a surface potential meter placed at the position of the developing unit to obtain a charging ability. At this time, the charging conditions (DC applied voltage to the charger, superimposed AC amplitude, frequency, etc.) were constant for comparison. The obtained results were subjected to rank determination according to the following criteria using the photoreceptor of Comparative Example 1 as a reference.
A: Improved by 10% or more compared to the reference, very good level B: Improved by 5% or more compared with the reference, good level Δ: Level equivalent to the reference (3) Residual potential The produced electrophotographic photosensitive member is developed. The charger was adjusted so that the surface potential at the vessel position was −450 V (dark potential), and then the light amount of the image exposure light source was adjusted to be the maximum, and image exposure was performed. The surface potential of the electrophotographic photosensitive member was measured with a surface potential meter installed at the position of the developing unit to obtain a residual potential. The obtained results were subjected to rank determination according to the following criteria using the photoreceptor of Comparative Example 1 as a reference.
A: Improved by 10% or more compared to the reference, very good level B: Improved by 5% or more compared with the reference, good level Δ: Level equivalent to the reference (4) Sensitivity After adjusting the charger so that the surface potential at the position was -450 V (dark potential), image exposure was performed. The light amount of the image exposure light source was adjusted so that the surface potential was −100 V (bright potential), and the exposure amount at that time was defined as sensitivity. The obtained results were subjected to rank determination according to the following criteria using the photoreceptor of Comparative Example 1 as a reference.
◎: Improved by 10% or more compared to the reference, very good level ○: Improved by 5% or more compared with the reference, good level △: Level equivalent to the reference (5) Potential unevenness The developed electrophotographic photosensitive member is developed. In the state where the charger is adjusted so that the dark part potential at the developing unit position becomes −450 V, and the light amount of the image exposure light source is adjusted so that the bright part potential at the developing unit position becomes −100 V, the dark part potential and the bright part potential In-plane distribution was measured. The difference between the maximum value and the minimum value was defined as potential unevenness. The obtained results were subjected to rank determination according to the following criteria using the photoreceptor of Comparative Example 1 as a reference.
A: Improved by 10% or more compared to the reference, very good level B: Improved by 5% or more compared with the reference, good level Δ: Level equivalent to the reference (6) Optical memory The optical memory potential is the dark part potential at the position of the developing device. Is determined by measuring the surface potential of the photosensitive member with a potential sensor in a state where the charging device is adjusted to be −450 V and the light amount of the image exposure light source is adjusted so that the bright portion potential at the developing device position is −100 V. It was. The difference in potential between the surface potential in the non-image exposure state and the time when the image was once exposed and then charged again was measured to obtain an optical memory. The obtained results were subjected to rank determination according to the following criteria using the photoreceptor of Comparative Example 1 as a reference.
A: Improved by 10% or more compared to the reference, very good level B: Improved by 5% or more compared with the reference, good level Δ: Level equivalent to the reference (7) 405 nm light transmittance Spectral sensitivity characteristics are constant Evaluation was performed by the reciprocal of the amount of light necessary to attenuate light from the dark part potential to the constant light part potential. That is, the amount of potential attenuation per unit energy of light is defined as the spectral sensitivity with respect to the exposure wavelength, and the spectral sensitivity at each wavelength when the exposure wavelength is changed is measured. Evaluation was performed using numerical values normalized by the spectral sensitivity peak value. More specifically, in order to evaluate the transmittance of 405 nm light, the transmittance was evaluated based on the spectral sensitivity of 405 nm light.
(8) Cleaning property The cleaning property was evaluated by the cleaning blade pressure at which cleaning residual toner starts to be generated. Specifically, after the endurance of passing 1000 sheets of A4 copy paper, the surface of the photoconductor is observed, and the presence or absence of cleaning residual toner is repeatedly observed while gradually reducing the cleaning blade pressure, and the residual cleaning remains. The cleaning blade pressure at which toner began to develop was examined. The obtained results were ranked by relative evaluation when the value of the photoconductor of Comparative Example 1 was set as a reference, that is, 100%. It can be interpreted that the lower the cleaning blade pressure at which the cleaning residual toner starts to be generated, the wider the cleaning latitude and the better the cleaning property.
◎: Less than 80%, very good level compared to the reference ○: 80% or more, less than 95%, better level than the reference △: Level equivalent to the reference The result obtained is that of Comparative Example 1 It shows in Table 7 with a result.

表７の結果から、青色半導体レーザー（４０５ｎｍ）、１２００ｄｐｉの画像で、解像度が向上した。これは、表面領域層に周期表第１３族元素の極大値を２個持つようにすることで解像度を向上させることができ、本来のスポット径を絞った効果が十分に発揮されることがわかった。

From the results in Table 7, the resolution was improved in a blue semiconductor laser (405 nm) and a 1200 dpi image. It can be seen that the resolution can be improved by having two maximum values of Group 13 elements of the periodic table in the surface region layer, and the effect of narrowing down the original spot diameter is sufficiently exhibited. It was.

  Further, by creating a photoconductor so as to satisfy all the requirements of the present invention as in the surface region layer of Example 3, an improvement in potential characteristics was observed, and effects were obtained particularly with respect to charging ability and residual potential. .

<Example 4>
Using the plasma CVD apparatus shown in FIG. 2, on the aluminum cylinder (support) having a mirror finish of 84 mm in diameter and 381 mm in length so as to have the layer structure shown in FIG. The deposited films were sequentially stacked. A photoreceptor comprising a lower injection blocking layer, a photoconductive layer, a change layer, and a surface layer was produced.

At this time, as shown in Table 8, the flow rate of B ₂ H ₆ gas introduced into each of the maximum value formation regions of the change layer and the surface layer is changed, and the maximum value of the boron atom concentration of the Group 13 element of the periodic table is changed. Changed. The flow rate of the B ₂ H ₆ gas is 120 and 100 [mL / min (normal)] for the photoreceptor 4-a, 110 and 100 [mL / min (normal)] for 4-b, and 100 for 4-c, respectively. , 100 [mL / min (normal)] and 4-d to 4-g were 130 and 80 [mL / min (normal)], respectively.

Further, by changing the B ₂ H ₆ gas introduced into the region after the maximum value formation of the change layer and the region before the maximum value formation of the surface layer, the minimum of the group 13 element of the periodic rule existing between the two adjacent maximum values is changed. The value was changed. The photoconductors 4-a to 4-c each have a flow rate of B ₂ H ₆ gas of 30 [mL / min (normal)], 4-d is 70 [mL / min (normal)], and 4-e is 60, respectively. [ML / min (normal)] and 4-f were each 50 [mL / min (normal)], and 4-g was 0 [mL / min (normal)].
Table 11 shows the maximum and minimum values at that time.

  The prepared photoreceptor was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 12.

＜実施例５＞
図２に示したプラズマＣＶＤ装置を用い、図１に示した層構成となるように、直径８４ｍｍ、長さ３８１ｍｍの鏡面加工を施したアルミニウムシリンダー（支持体）上に、表９に示した条件で堆積膜を順次積層した。下部注入阻止層、光導電層、変化層、表面層からなる感光体を製作した。

<Example 5>
Using the plasma CVD apparatus shown in FIG. 2, the conditions shown in Table 9 were applied on an aluminum cylinder (support) having a mirror finish of 84 mm in diameter and 381 mm in length so as to have the layer structure shown in FIG. The deposited films were sequentially stacked. A photoreceptor comprising a lower injection blocking layer, a photoconductive layer, a change layer, and a surface layer was produced.

  In Example 5, the periodic table distributed in the change layer and in the surface layer is obtained by changing the film thickness by changing the deposition time for forming the region before forming the maximum value in the surface layer. The distance between the two maximum values of the Group 13 element content was set to 80 nm or more and 1200 nm or less. The film thickness of the region before the maximum value formation in the surface layer is 0.01 μm for the photoreceptor 5-a, 0.03 μm for 5-b, 0.05 μm for 5-c, 0.89 μm for 5-d, 5- In e, 0.93 μm, and in 5-f, 1.13 μm.

  Table 11 shows the content and maximum value at that time.

  The produced photoreceptor was evaluated in the same manner as in Example 3. The evaluation results are shown in Table 12.

＜実施例６＞
図２に示したプラズマＣＶＤ装置を用い、図１に示した層構成となるように、直径８４ｍｍ、長さ３８１ｍｍの鏡面加工を施したアルミニウムシリンダー（支持体）上に、表１０に示した条件で堆積膜を順次積層した。下部注入阻止層、光導電層、変化層、表面層からなる感光体を製作した。

<Example 6>
Using the plasma CVD apparatus shown in FIG. 2, on the aluminum cylinder (support) having a mirror finish of 84 mm in diameter and 381 mm in length so as to have the layer structure shown in FIG. The deposited films were sequentially stacked. A photoreceptor comprising a lower injection blocking layer, a photoconductive layer, a change layer, and a surface layer was produced.

In Example 6, the flow rate of B ₂ H ₆ gas introduced into the surface region layer was changed so that the maximum value on the surface side was greater than the maximum value on the photoconductive layer side, contrary to Example 3. did.

  Table 11 shows the content and maximum value at that time.

  The prepared photoreceptor was evaluated in the same manner as in Example 3. The evaluation results are shown in Table 12.

表１２の実施例４の評価結果から、光導電層側の極大値を５．０×１０¹⁸ｃｍ³以上にすることで、帯電能が向上することがわかる。かつ、極大値間の含有量が２．５×１０¹⁸個／ｃｍ³以下にすることで、解像度の向上が図れることがわかる。極大値間の含有量が２．５×１０¹⁸個／ｃｍ³よりも多くなると、極大値が実質的に１個と同じになり解像度改善の効果が見られない。

From the evaluation results of Example 4 in Table 12, it can be seen that the charging ability is improved by setting the maximum value on the photoconductive layer side to 5.0 × 10 ¹⁸ cm ³ or more. It can also be seen that the resolution can be improved by setting the content between the maximum values to 2.5 × 10 ¹⁸ pieces / cm ³ or less. When the content between the maximum values exceeds 2.5 × 10 ¹⁸ pieces / cm ³ , the maximum value becomes substantially the same as one, and the effect of improving the resolution is not seen.

  Further, from the results of Example 5, when the maximum value interval is smaller than 100 nm, the maximum value is substantially the same as one, and therefore improvement in resolution, charging ability, and residual potential is hardly observed. Furthermore, when it becomes larger than 1000 nm, it turns out that the improvement effect is somewhat reduced in the resolution, the residual potential, and the sensitivity.

  From the results of Example 3 and Example 6, it was found that the resolution was particularly good by increasing the maximum value on the photoconductive layer side than the maximum value on the surface side.

From the above, by having at least two local maximum values of Group 13 elements of the periodic table, the resolution is improved, and the local maximum value on the photoconductive layer side is larger than 5.0 × 10 ¹⁸ / cm ^3. In addition, by setting the maximum value interval to 100 nm or more and 1000 nm or less, it is possible to improve electrical characteristics such as charging ability, residual potential, and sensitivity.

<Example 7>
Using the plasma CVD apparatus shown in FIG. 2, the conditions shown in Table 13 were applied on an aluminum cylinder (support) having a mirror finish of 84 mm in diameter and 381 mm in length so as to have the layer structure shown in FIG. The deposited films were sequentially stacked. A photoreceptor comprising a lower injection blocking layer, a photoconductive layer, a change layer, and a surface layer was produced.

In the embodiment, NO gas, SiF ₄ is formed during the formation of the deposited film on the surface layer so that the content of oxygen atoms and / or fluorine atoms in the surface layer has a maximum value in the thickness direction in the surface layer. Gas was introduced.

Specifically, NO gas and SiF ₄ gas diluted with helium gas are used, and each gas flow rate is changed at a constant rate within the maximum value forming region, thereby allowing the maximum value of oxygen atoms and the maximum value of fluorine atoms. And having maximum values of oxygen atom and fluorine atom, respectively.

Further, by changing the flow rate of B ₂ H ₆ which is a boron raw material of Group 13 element of the periodic table, the maximum value of Group 13 element of the periodic table in the change layer is 7.5 × 10 ¹⁸ pieces / cm ³ , surface The maximum value of the group 13 element of the periodic table in the layer is 4.0 × 10 ¹⁸ pieces / cm ³ , and the minimum value of the group 13 element of the periodic table existing between the maximum value of the change layer and the maximum value of the surface layer Is 1.5 × 10 ¹⁷ pieces / cm ³ .

  Further, the distance between the two maximum values of the group 13 element content of the periodic table distributed in the change layer and the surface layer is 300 nm.

  The prepared photoreceptor was evaluated in the same manner as in Example 3. The evaluation results are shown in Table 14.

表１４から、表面層中に酸素原子および／またはフッ素原子の極大値を持たせることで、クリーニング性の向上が見られた。

From Table 14, the cleaning property was improved by giving the surface layer a maximum value of oxygen atoms and / or fluorine atoms.

[Example 8]
Using the plasma CVD apparatus shown in FIG. 2, a deposited film is sequentially laminated under the conditions shown in Table 15 on a mirror-finished aluminum cylinder (support) having a diameter of 84 mm and a length of 381 mm. A photoconductor comprising a photoconductive layer and a surface region layer was produced. As shown in Table 15, the amount of N ₂ gas and B ₂ H ₆ gas introduced was changed during the formation of the surface region layer. As a method of introducing gas in the maximum value formation in Table 15, N ₂ gas and B ₂ H ₆ gas are used, and are linearly increased from a constant value to the value in Table 15 over a predetermined time, and then again at the same rate. It was decreased linearly to the initial constant value.

In addition, the amount of NO gas and SiF ₄ gas introduced was changed so that the maximum value was obtained.

作製した感光体の表面領域層について、実施例１と同様にしてSIMS測定を行った。窒素原子とホウ素原子の含有量について、図１１（ｂ）に示す分布を持つことが分かった。さらに、NOガス、SiF₄ガスの導入量を変化させて得られた表面領域層の極大値におけるホウ素原子の含有量は、光導電層側から、8.0×１０¹⁸個/cm³、4.0×１０¹⁸個/cm³、ホウ素原子の極大値間隔は300nm、窒素原子の極大値と最小値との間隔は１５０nmであった。また、窒素原子含有率の極大値は、N/(Si+N)の表記で55atm%であった。

SIMS measurement was performed in the same manner as in Example 1 for the surface region layer of the produced photoreceptor. About content of a nitrogen atom and a boron atom, it turned out that it has distribution shown in FIG.11 (b). Furthermore, the content of boron atoms at the maximum value of the surface region layer obtained by changing the introduction amount of NO gas and SiF ₄ gas is 8.0 × 10 ¹⁸ atoms / cm ³ , 4.0 × 10 from the photoconductive layer side. ¹⁸ / cm ^3, the maximum value interval of the boron atoms is 300 nm, distance between the maximum value and the minimum value of the nitrogen atom was 150 nm. Further, the maximum value of the nitrogen atom content was 55 atm% in terms of N / (Si + N).

  The prepared photoreceptor was set in an iRC6800-405 nm modified machine, and the same evaluation as in Example 3 was performed for each item of (1) resolution to (8) cleaning property. In this example, the following item (9) Image defect was also evaluated. However, each of the items (1) to (9) was evaluated using the photoconductor of Comparative Example 2 as a reference. Table 20 shows the evaluation results.

(9) Image defect The image defect was evaluated by the number of white spots having a diameter of 0.1 mm or less in a 100% pixel density image and black spots having a diameter of 0.1 mm or less in a 0% pixel density image. Most of the white spots and black spots having a diameter exceeding 0.1 mm are caused by dust adhering to the support before the start of film formation of the photoreceptor. The occurrence of such image defects is less dependent on the conditions during film formation, and it is essential to eliminate image defects by improving processes such as dust reduction. I know more. For this reason, the evaluation was performed by paying attention to the number of relatively small image defects having a diameter of 0.1 mm or less, which can be influenced by the conditions during film formation, excluding the evaluation target. As for the obtained results, the rank of the photoconductor was determined by a relative evaluation when the value of the photoconductor having a layer structure shown in Comparative Example 2 described later is set as a reference, that is, 100%.

◎: Less than 60%, very good level compared to reference ○: 60% or more, less than 90%, better level than reference △: Level equivalent to reference
[Comparative Example 2]
In the same manner as in Example 8, the deposited films were sequentially laminated under the conditions shown in Table 16 to prepare a photoreceptor composed of a lower injection blocking layer, a photoconductive layer, an upper injection blocking layer, and a surface layer. Created photoconductor
When SIMS measurement was performed in the same manner as in Example 8, the distribution shown in FIG. 16C was obtained, and the maximum value of boron atoms was 8.0 × 10 ¹⁸ atoms / cm ³ . The maximum value of nitrogen atom content was 57 atm% in the notation of N / (Si + N).

  About the produced photoreceptor, it carried out similarly to Example 8, and evaluated the characteristic. The results are shown in Table 18.

[実施例９]
実施例８と同様にして表１７に示した条件で堆積膜を順次積層し、下部注入阻止層、光導電層、及び、表面領域層からなる感光体を製作した。このとき、表面領域層にNOガス、SiF₄ガスを用いなかった他は、実施例８と同様にして感光体を製作した。作製した感光体の表面領域層について、実施例１と同様にしてSIMS測定した。窒素原子とホウ素原子の含有量について、図１１（ｂ）に示す分布を持つこと分かった。ホウ素原子の極大値は、光導電層側から8.0×１０¹⁸個/cm³、4.0×１０¹⁸個/cm³であった。そして、ホウ素原子の極大値間隔は200nm、窒素原子の極大値と最小値との間隔は、１００nmであった。また、窒素原子含有率の極大値は、N/(Si+N)の表記で65atm%であった。

[Example 9]
The deposited films were sequentially laminated in the same manner as in Example 8 under the conditions shown in Table 17 to produce a photoreceptor composed of a lower injection blocking layer, a photoconductive layer, and a surface region layer. At this time, a photoconductor was manufactured in the same manner as in Example 8 except that NO gas and SiF ₄ gas were not used for the surface region layer. SIMS measurement was performed on the surface region layer of the produced photoreceptor in the same manner as in Example 1. About content of a nitrogen atom and a boron atom, it turned out that it has distribution shown in FIG.11 (b). The maximum values of boron atoms were 8.0 × 10 ¹⁸ atoms / cm ³ and 4.0 × 10 ¹⁸ atoms / cm ³ from the photoconductive layer side. The interval between the maximum values of the boron atoms was 200 nm, and the interval between the maximum value and the minimum value of the nitrogen atoms was 100 nm. The maximum value of the nitrogen atom content was 65 atm% in the notation of N / (Si + N).

  The characteristics of the produced photoreceptor were evaluated in the same manner as in Example 8. The results are shown in Table 18.

結果から明らかなように、青色半導体レーザー（405nm）で、1200dpiの画像では、解像
度が向上した。これは、表面領域層にホウ素原子、窒素原子の極大値を2個持ち、かつ酸
素原子及びフッ素原子の極大値を持つ実施例８のような表面領域層を用いると、ドット再
現性を向上させることができ、本来のスポット径を絞った効果が十分に発揮されることが
わかった。また、実施例８の表面領域層を持つ感光体は優れた光導電特性を有することが分かった。

As is clear from the results, the resolution was improved in the 1200 dpi image with the blue semiconductor laser (405 nm). This is because dot reproducibility is improved by using the surface region layer as in Example 8 having two maximum values of boron atoms and nitrogen atoms and having maximum values of oxygen atoms and fluorine atoms in the surface region layer. It was found that the effect of narrowing the original spot diameter was sufficiently exhibited. It was also found that the photoreceptor having the surface region layer of Example 8 had excellent photoconductive properties.

Furthermore, it was found that the resolution, residual potential, optical memory, and CLN properties were further improved by having maximum values of oxygen atoms and fluorine atoms.

[Example 10]
In the same manner as in Example 8, deposited films were sequentially laminated under the conditions shown in Table 19 to prepare a photoconductor comprising a lower injection blocking layer, a photoconductive layer, and a surface region layer. Six types of photoconductors 8I to 8N were prepared in the same manner as in Example 8 except that the flow rate of the B ₂ H ₆ gas introduced into the surface region layer was changed. The produced photoreceptor was subjected to SIMS measurement. About content of a nitrogen atom and a boron atom, it turned out that it has the distribution shown to Fig.9 (a) or (b). As shown in Table 20, the maximum values of boron atoms are 4.5 to 5.5 × 10 ¹⁸ atoms / cm ³ and 2.4 × 10 ¹⁹ atoms / cm ³ from the photoconductive layer side, and the maximum values of nitrogen atom content are It was 50 atm% in the notation of N / (Si + N). The interval between the maximum values of boron atoms was 350 nm, and the interval between the maximum value and the minimum value of nitrogen atoms was 175 nm.

  The characteristics of the produced photoreceptor were evaluated in the same manner as in Example 8. The results are shown in Table 21.

結果から明らかなように、最も光導電層側に位置する周期表第１３族元素の極大値が、5.0×１０¹⁸個/cm³以上であると、解像度や帯電能に於いて、更なる特性の向上が図られ、周期表第１３族元素の隣接する２つの極大値の間に存在する周期表第１３族元素の最小値が、2.5×１０¹⁸個/ cm³以下であると、帯電能について、更なる特性の向上が認められた。また、周期表第１３族元素が、極大領域として含まれていても、極大値として含まれている場合と同様の光電特性の効果が得られることが分かった。

As is clear from the results, when the maximum value of the group 13 element of the periodic table located closest to the photoconductive layer is 5.0 × 10 ¹⁸ elements / cm ³ or more, further characteristics in terms of resolution and chargeability are obtained. When the minimum value of the group 13 element of the periodic table existing between two adjacent maximum values of the group 13 element of the periodic table is 2.5 × 10 ¹⁸ pieces / cm ³ or less, Further improvement in properties was observed for. Further, it was found that even when the Group 13 element of the periodic table is included as a maximum region, the same photoelectric characteristic effect as that when it is included as a maximum value can be obtained.

[Example 11]
In the same manner as in Example 8, the flow rate of B ₂ H ₆ gas introduced into the surface region layer was changed from that in Example 8 to sequentially deposit deposited films under the conditions shown in Table 22, and the lower injection blocking layer, light A photoconductor comprising a conductive layer and a surface region layer was produced.

A photoconductor was prepared in the same manner as in Example 8 except that the flow rate of the B ₂ H ₆ gas introduced into the surface region layer was changed. The produced photoreceptor was subjected to SIMS measurement in the same manner as in Example 1. About content of a nitrogen atom and a boron atom, as shown to Fig.11 (a), it turned out that it has the distribution from which the maximum value by the free surface side becomes large among two periodic table group 13 element maximum values. The maximum values of boron atoms were 5.1 × 10 ¹⁸ atoms / cm ³ and 6.4 × 10 ¹⁸ atoms / cm ³ from the photoconductive layer side. The interval between the maximum values of boron atoms was 180 nm, and the interval between the maximum value and the minimum value of nitrogen atoms was 90 nm. The maximum value of nitrogen atom content was 50 atm% in the notation of N / (Si + N).

The characteristics of the produced photoreceptor were evaluated in the same manner as in Example 8. The results are shown in Table 23.

結果から明らかなように、表面領域層にホウ素原子、窒素原子の極大値を2個持つよう
にし、かつ酸素原子及びフッ素原子の極大値を持つようにことにより、感度、電位ムラ、
光メモリー、透過性、画像欠陥の点で特性の向上が確認された。しかし、表面領域層に含
まれる2つの周期表第１３族元素極大値のうち、自由表面側の極大値が大きくなるように
含有させたこの実施例１１は、解像度や帯電能、残留電位の点では特性の向上は確認できなかった。

As is clear from the results, the surface region layer has two maximum values of boron atoms and nitrogen atoms, and has the maximum values of oxygen atoms and fluorine atoms, so that sensitivity, potential unevenness,
Improvements in characteristics were confirmed in terms of optical memory, transparency, and image defects. However, this Example 11, which is included so that the maximum value on the free surface side of the two periodic table group 13 element maximum values contained in the surface region layer, is increased in terms of resolution, charging ability, and residual potential. However, the improvement of characteristics could not be confirmed.

[Example 12]
In the same manner as in Example 8, the flow rate of B ₂ H ₆ gas introduced into the surface region layer and the film formation time were changed from those in Example 8, and the two group 13 element maxima included in the surface region layer were increased. The deposited films were sequentially stacked under the conditions shown in Table 24 by changing the distance between the maximum values. Five types of photoreceptors comprising a lower injection blocking layer, a photoconductive layer, and a surface region layer were produced. The produced photoreceptor was subjected to SIMS measurement. The content of nitrogen atoms and boron atoms was found to have the distribution shown in FIG. The maximum values of boron atoms were 6.2 × 10 ¹⁸ atoms / cm ³ and 6.2 × 10 ¹⁸ atoms / cm ³ from the photoconductive layer side. As shown in Table 25, the maximum value interval of boron atoms was 80 to 7070 nm. The maximum value of nitrogen atom content was 50 atm% in the notation of N / (Si + N).

  The characteristics of the produced photoreceptor were evaluated in the same manner as in Example 8. The results are shown in Table 26.

＊３：０.０１〜１.００

* 3: 0.01 to 1.00

結果から明らかなように、表面領域層に含まれる2つの周期表第１３族元素極大値の極大値間距離は、膜の厚さ方向で100nm以上1000nm以下の範囲にあることが、解像度や帯電能、残留電位、感度の点からより好ましいことが分かった。

As is clear from the results, the distance between the maximum values of the two group 13 element maximum values included in the surface region layer is in the range of 100 nm to 1000 nm in the film thickness direction. From the viewpoint of performance, residual potential, and sensitivity, it was found to be more preferable.

[Example 13]
In the same manner as in Example 8, the flow rate of N ₂ gas introduced into the surface region layer is changed, and the ratio between the maximum value and the minimum value of the nitrogen atom content contained in the surface region layer (maximum value / minimum value). The deposited films were sequentially laminated under the conditions shown in Table 27 while changing the above. Four types of photoconductors (13T to 13W) comprising a lower injection blocking layer, a photoconductive layer, and a surface region layer were produced. The produced photoreceptor was subjected to SIMS measurement. It was found that the content of nitrogen atoms and boron atoms had the distribution shown in FIG. The maximum values of boron atoms were 8.0 × 10 ¹⁸ atoms / cm ³ and 8.0 × 10 ¹⁸ atoms / cm ³ from the photoconductive layer side. The interval between the maximum values of boron atoms was 170 nm, and the interval between the maximum value and the minimum value of nitrogen atoms was 85 nm. Further, the maximum value of the nitrogen atom content was 43 to 67 atm% in terms of N / (Si + N). Table 28 shows the maximum values with respect to the minimum value of the nitrogen atom content.

The characteristics of the produced photoreceptor were evaluated in the same manner as in Example 8. The results are shown in Table 29.

結果から明らかなように、表面領域層に含まれる窒素原子含有率の最小値に対する極大値の値は、110%以上であることが、画像欠陥の点からより好ましいことが分かる。

As is apparent from the results, the maximum value with respect to the minimum value of the nitrogen atom content contained in the surface region layer is more preferably 110% or more from the viewpoint of image defects.

[Example 14]
A photoconductor was prepared in the same manner as in Example 8 except that the film formation time of the second upper injection blocking layer (TBL-1) was changed from that in Example 8 under the conditions shown in Table 30. Specifically, deposition is performed by changing the distance between the minimum value between the maximum values of two nitrogen atom maximum values contained in the surface region layer and the maximum value on the photoconductive layer side of the two nitrogen atom maximum values. Films were sequentially laminated to produce a photoreceptor (14X-14AC) comprising a lower injection blocking layer, a photoconductive layer, and a surface region layer.

It was fabricated in the same manner as in Example 2 except that the film formation time of the second upper injection blocking layer (TBL-1) to be introduced into the surface region layer was changed. The produced photoreceptor was subjected to SIMS measurement. About content of a nitrogen atom and a boron atom, it turned out that it has a peak shown in FIG.16 (b). The maximum values of boron atoms were 8.0 × 10 ¹⁸ atoms / cm ³ and 8.0 × 10 ¹⁸ atoms / cm ³ from the photoconductive layer side. As shown in Table 31, the interval between the maximum value and the minimum value of nitrogen atoms was 30 to 310 nm. The maximum value of the nitrogen atom content was 38 atm% in the notation of N / (Si + N).

The characteristics of the produced photoreceptor were evaluated in the same manner as in Example 2. The results are shown in Table 32.

結果から明らかなように、表面領域層に含まれる2つの窒素原子極大値間の最小値と光導電層側の極大値との距離は、膜の厚さ方向で４０nm以上300nm以下の範囲にあることが、画像欠陥の点からより好ましいことが分かった。

As is apparent from the results, the distance between the minimum value between the two nitrogen atom maximum values contained in the surface region layer and the maximum value on the photoconductive layer side is in the range of 40 nm to 300 nm in the film thickness direction. Has been found to be more preferable in terms of image defects.

[Example 15]
A deposited film was sequentially laminated in the same manner as in Example 8 except that all of the surface region layer contained a group 13 element of the periodic table under the conditions shown in Table 33, and a lower injection blocking layer, a photoconductive layer, and A photoreceptor comprising a surface region layer was prepared. The produced photoreceptor was subjected to SIMS measurement. It was found that the content of nitrogen atoms and boron atoms had the distribution shown in FIG. The maximum values of boron atoms were 8.0 × 10 ¹⁸ atoms / cm ³ and 8.0 × 10 ¹⁸ atoms / cm ³ from the photoconductive layer side. The interval between the maximum values of boron atoms was 300 nm, and the interval between the maximum value and the minimum value of nitrogen atoms was 150 nm. The maximum value of the nitrogen atom content was 39 atm% in terms of N / (Si + N).

The characteristics of the produced photoreceptor were evaluated in the same manner as in Example 8. The results are shown in Table 34.

結果から明らかなように、表面領域層のすべてに周期表第１３族元素を含ませた上で、
周期表第１３族元素が2つの極大値を持つような場合においても、評価した全項目で特性
の改善が見られることが分かった。

As is apparent from the results, all of the surface region layers contain Group 13 elements of the periodic table.
It was found that even when the Group 13 element of the periodic table had two maximum values, the characteristics were improved in all the evaluated items.

[Example 16]
In the same manner as in Example 8, the flow rate of the B ₂ H ₆ gas in Example 8, N ₂ , so that the Group 13 element content of the periodic table and the nitrogen element content have the same phase and maximum values in the surface region layer. The deposited films were sequentially stacked under the conditions shown in Table 23 while changing the gas flow rate. A photoreceptor comprising a lower injection blocking layer, a photoconductive layer, and a surface region layer was produced. The produced photoreceptor was subjected to SIMS measurement. It was found that the contents of nitrogen atoms and boron atoms had the distribution shown in FIG. The maximum values of boron atoms were 5.1 × 10 ¹⁸ atoms / cm ³ and 5.1 × 10 ¹⁸ atoms / cm ³ from the photoconductive layer side. The interval between the maximum values of boron atoms was 500 nm, and the interval between the maximum value and the minimum value of nitrogen atoms was 150 nm. The maximum value of the nitrogen atom content was 39 atm% in terms of N / (Si + N).

The characteristics of the produced photoreceptor were evaluated in the same manner as in Example 8. The results are shown in Table 36.

結果から明らかなように、表面領域層において周期表第１３族元素含有率と窒素元素の
含有率が同位相でピークを持つような場合には、画像欠陥以外で特性の改善が見られることが分かった。

As is apparent from the results, when the content of the Group 13 element in the periodic table and the content of the nitrogen element have peaks in the same phase in the surface region layer, improvement in characteristics other than image defects may be observed. I understood.

[Example 17]
Except that the flow rate of the N ₂ gas introduced into the lower injection blocking layer was changed from that in Example 8, the deposited films were sequentially laminated under the conditions shown in Table 37 in the same manner as in Example 8, and the lower injection blocking layer, light A photoconductor comprising a conductive layer and a surface region layer was produced. The produced photoreceptor was subjected to SIMS measurement. Regarding the content of nitrogen atoms and boron atoms, it was found that in the content distribution shown in FIG. 11 (a), the two local maximum values of nitrogen atoms are equal and the two local maximum values of boron atoms are equal. . The maximum values of boron atoms were 6.4 × 10 ¹⁸ atoms / cm ³ and 6.4 × 10 ¹⁸ atoms / cm ³ from the photoconductive layer side. The interval between the maximum values of boron atoms was 700 nm, and the interval between the maximum value and the minimum value of nitrogen atoms was 350 nm. The maximum value of the nitrogen atom content was 62 atm% in the notation of N / (Si + N).

  The characteristics of the produced photoreceptor were evaluated in the same manner as in Example 8. The results are shown in Table 38.

結果から明らかなように、下部注入阻止層に窒素原子を導入した場合においても、評価
した全項目で特性の改善が見られることが分かった。

As is clear from the results, it was found that even when nitrogen atoms were introduced into the lower injection blocking layer, the characteristics were improved in all the evaluated items.

[Example 18]
A change layer was introduced at the beginning of the surface region layer. When the change layer is deposited, the flow rate of SiH ₄ gas, the flow rate of B ₂ H ₆ gas, and the flow rate of N ₂ gas are changed to make the photoconductive layer and the first upper injection blocking layer optically continuous. The deposited films were sequentially laminated under the conditions shown in Table 39 in the same manner as in Example 8 except that they were different from those in Example 8. Photoconductors (18-A to 18-H) composed of a lower injection blocking layer, a photoconductive layer, and a surface region layer were produced. The produced photoreceptor was subjected to SIMS measurement. About content of a nitrogen atom and a boron atom, it turned out that it has a peak shown to Fig.16 (a). The maximum values of boron atoms were 1.6 × 10 ¹⁹ atoms / cm ³ and 4.0 × 10 ¹⁸ atoms / cm ³ from the photoconductive layer side. The interval between the maximum values of boron atoms was 810 nm, and the interval between the maximum value and the minimum value of nitrogen atoms was 350 nm. The maximum value of the nitrogen atom content was 65 atm% in terms of N / (Si + N). Further, the spectral reflection spectrum of the produced photosensitive drum was measured using MCPD-2000 manufactured by Otsuka Electronics. FIG. 17A shows the spectral reflection spectra of the photoconductors 18-A to 18-D, and FIG. 17B shows the spectral reflection spectra of the photoconductors 18-E to 18-H. The photoreceptors 18-A to 18-D have a minimum value (Min) and a maximum value (Max) of reflectance (%) in the wavelength range of 350 nm to 680 nm, and 0% ≦ Max (%) ≦ 20% and 0 ≦ ( Max−Min) / (100−Max) ≦ 0.15, and the photoreceptors 18-E to 18-H have a minimum value (Min) and a maximum value (%) of reflectance (%) in the wavelength range of 350 nm to 680 nm ( Max) did not satisfy the above relationship. In addition, the numerical value described in FIG. 17A and FIG. 17B is a value of (Max-Min) / (100-Max).

  Photoelectric characteristics of the produced photoreceptor were evaluated in the same manner as in Example 8. The results are shown in Table 40.

結果から、光導電層から上部注入阻止層を光学的に連続とし、波長350nmから680nmの範囲の反射率(%)の最小値(Ｍin)と最大値(Ｍax)が上記範囲を満たしている感光体は、電位ムラが向上し、特に、電位ムラの中で露光ムラが向上することが分かった。実施例１〜１８の感光体は、波長350nmから680nmの範囲の反射率(%)の最小値(Ｍin)と最大値(Ｍax)が上記関係を満たしていた。

From the results, the photoconductive layer and the top injection blocking layer are optically continuous, and the minimum value (Min) and maximum value (Max) of the reflectance (%) in the wavelength range of 350 nm to 680 nm satisfy the above range. It was found that the body was improved in potential unevenness, and in particular, exposure unevenness was improved in the potential unevenness. In the photoreceptors of Examples 1 to 18, the minimum value (Min) and the maximum value (Max) of the reflectance (%) in the wavelength range of 350 nm to 680 nm satisfied the above relationship.

1 is a schematic cross-sectional view illustrating an example of an electrophotographic photosensitive member of the present invention. It is a typical block diagram which shows an example of the plasma CVD deposition apparatus using the high frequency of RF band which can be used for manufacture of the electrophotographic photoreceptor of this invention. 1 is a schematic configuration diagram illustrating an example of a color electrophotographic apparatus to which an electrophotographic photosensitive member of the present invention can be applied. It is an example of the depth profile explaining the maximum value of the periodic table group 13 element (boron atom), oxygen atom, and fluorine atom content in the surface region layer in the electrophotographic photoreceptor of the invention. It is a graph showing an example of the measurement result of the spectral sensitivity characteristic of an electrophotographic photoreceptor. 4 is a graph showing the results of measuring the correlation between the nitrogen atom concentration in the surface layer of the electrophotographic photosensitive member prepared in Example 1 and the sensitivity to light with a wavelength of 405 nm. It is a distribution map of the content rate of the periodic table group 13 element with respect to the thickness direction on the photoconductive layer in the electrophotographic photosensitive member of the present invention. It is a figure which shows the content rate distribution of the periodic table group 13 element and nitrogen atom in the thickness direction of the surface region layer of an example of the electrophotographic photosensitive member of the present invention. (A) It is a figure which shows the content rate distribution of a periodic table group 13 element in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention, and a nitrogen atom. (B) It is a figure which shows the content rate distribution of a periodic table group 13 element and a nitrogen atom in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention. It is a figure which shows the content rate distribution of a periodic table group 13 element in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention, and a nitrogen atom. (A) It is a figure which shows the content rate distribution of a periodic table group 13 element in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention, and a nitrogen atom. (B) It is a figure which shows the content rate distribution of the periodic table group 13 element and nitrogen atom in the thickness direction of the surface region layer of the other example of the electrophotographic photosensitive member of the present invention. It is a figure which shows the content rate distribution of a periodic table group 13 element in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention, and a nitrogen atom. It is a figure which shows the content rate distribution of a periodic table group 13 element in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention, and a nitrogen atom. (A) It is a figure which shows the content distribution of the nitrogen atom in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention. (B) It is a figure which shows the content rate distribution of the nitrogen atom in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention. (A) It is a figure which shows the content rate distribution of the periodic table group 13 element in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention. (B) It is a figure which shows the content rate distribution of the periodic table group 13 element in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention. (A) And (b) is a figure which shows the content rate distribution of a periodic table group 13 element and a nitrogen atom in the thickness direction of the surface region layer of an example of the electrophotographic photoreceptor of this invention. (C) is a figure which shows the content rate distribution of the periodic table group 13 element and nitrogen atom in the thickness direction of the surface region layer of an example of the conventional electrophotographic photosensitive member. It is a figure which shows the spectral reflection spectrum of the electrophotographic photosensitive member of this invention.

Explanation of symbols

101 substrate 102 photoconductive layer 103 surface region layer 104 lower injection blocking layer 105 first upper injection blocking layer (TBL-1)
106 Intermediate layer 107 Second upper injection blocking layer (TBL-2)
108 Surface protective layer (SL)

Claims (13)

A photoconductive layer composed of a non-single crystal silicon film having at least silicon atoms as a base material on a conductive substrate, and silicon atoms and nitrogen atoms stacked on the photoconductive layer as base materials, at least a part A surface region layer made of a non-single crystal silicon nitride film containing a Group 13 element of the periodic table,
The electrophotographic photosensitive member, wherein the surface region layer has at least two maximum values of the content of Group 13 element in the periodic table with respect to the total number of constituent atoms in the thickness direction. A photoconductive layer composed of a non-single crystal silicon film having at least silicon atoms as a base material on a conductive substrate, and silicon atoms and nitrogen atoms stacked on the photoconductive layer as base materials, at least a part A surface region layer made of a non-single crystal silicon nitride film containing a Group 13 element of the periodic table,
The surface region layer is an electrophotographic photoreceptor having a change layer in which the composition ratio of silicon atoms and nitrogen atoms is changed and a surface layer in which the composition ratio of silicon atoms and nitrogen atoms is constant,
The change layer has at least one maximum value of the content of the group 13 element in the periodic table with respect to the total number of constituent atoms in the thickness direction, and the surface layer has a periodic table with respect to the total number of constituent atoms in the thickness direction. An electrophotographic photosensitive member having at least one maximum value of the content of a group 13 element.   3. The electrophotographic photosensitive member according to claim 1, wherein an average concentration (atomic%) of nitrogen atoms in the surface layer satisfies 30 atomic% ≦ N / (Si + N) ≦ 70 atomic%.   The two adjacent maximum values of the group 13 element of the periodic table in the surface region layer are in a distance range of 100 nm or more and 1000 nm or less in the film thickness direction. The electrophotographic photosensitive member described.   5. The electrophotography according to claim 1, wherein the maximum value located closest to the photoconductive layer among the maximum values of the Group 13 elements in the periodic table in the surface region layer is the largest. Photoconductor. The local maximum value of the group 13 element of the periodic table in the surface region layer located at the most photoconductive layer side is 5.0 × 10 ¹⁸ pieces / cm ³ or more and / or between two adjacent local maximum values. 6. The electrophotographic photosensitive member according to claim 1, wherein the minimum value of Group 13 elements in the periodic table is 2.5 × 10 ¹⁸ pieces / cm ³ or less.   The electron according to any one of claims 1 to 6, wherein the surface region layer has at least one maximum value of the content ratio of oxygen atoms and / or fluorine atoms with respect to the total number of constituent atoms in the thickness direction. Photoconductor.   8. The electrophotographic photosensitive member according to claim 1, wherein the surface region layer has at least two maximum values of the content ratio of nitrogen atoms with respect to the total number of constituent atoms in the thickness direction.   9. The surface region layer according to claim 1, wherein the surface region layer alternately has a maximum value of nitrogen atom content and a maximum value of group 13 element content of the periodic table in the thickness direction. The electrophotographic photosensitive member described.   The surface region layer has a maximum value of nitrogen atom content and a maximum value of group 13 element content of the periodic table in the thickness direction from the photoconductive layer toward the free surface side. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member has a maximum value of group element content and a maximum value of nitrogen atom content.   The surface region layer has a maximum value on the photoconductive layer side of two adjacent maximum values in the thickness direction of the nitrogen atom content, and a minimum value between the two maximum values is a distance of 40 nm or more and 300 nm or less. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is provided.   In the surface region layer, the maximum value in the thickness direction of the nitrogen atom content rate is N / (Si + N) ≧ 30 atm%, and (maximum value / minimum value) is 110% or more with respect to the minimum value. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is provided.   The minimum value (Min) and the maximum value (Max) of the reflectance (%) in the wavelength range of 350 nm to 680 nm are 0% ≦ Max (%) ≦ 20% and 0 ≦ (Max−Min) / (100−Max). The electrophotographic photosensitive member according to claim 1, wherein ≦ 0.15 is satisfied.

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