JPS6343159A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve the electrophotographic characteristic and environmental resistance of a photosensitive body by forming an electric charge transfer layer of a semiconductor at least part of which is micro-crystallized and forming an electric charge generating layer of a laminate of an amorphous layer and a layer of a semiconductor at least part of which is micro-crystallized. CONSTITUTION:A barrier layer 22 consisting of a a-Si:H, etc., a photoconductive layer 23 consisting of the electric charge transfer layer 25 and the electric charge generating layer 26 and a surface layer 24 are laminated on a conductive substrate 21. The layer 25 is formed of the semiconductor material which is composed of Si as the base material and at least part of which is micro- crystallized (e.g.: muc-Si:H). The layer 26 is constituted by alternately laminating the thin layers 31, 32. One of the layers is formed of the amorphous material composed of the Si as the base material (e.g.: a-Si:H) and the other is formed of the semiconductor material which contains C and at least part of which is micro-crystallized (e.g.: muc-SiC:H). The thickness of the layers 31, 32 is preferably 30-500Angstrom .

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electrophotographic photoreceptor having excellent charging characteristics, dark decay characteristics, photosensitivity characteristics, environmental resistance, etc.

(Prior Art) Conventionally, materials for forming the photoconductive layer of an electrophotographic photoreceptor include CdS, ZnO, Se, and 5e-Te.

Inorganic materials such as As2Se3 or amorphous silicon or organic materials such as poly-N-vinylcarbazole (PVCz) or trinitrofluorenone (TNF) have been used. However, these conventional photoconductive materials have various problems in terms of photoconductive properties and manufacturing process, and these materials are used depending on the purpose of use, sacrificing the characteristics of the photoreceptor system to some extent. .

For example, Se, As, and CdS are materials that are harmful to the human body, and special consideration must be given to safety measures when manufacturing them. Therefore, there are problems in that the manufacturing equipment becomes complicated and the manufacturing cost is high, and in particular, Se and As need to be recovered, which adds to the recovery cost. In addition, since the crystallization temperature of Se or 5e-Te systems is as low as 65°C, they crystallize during repeated copying, causing problems with photoconductive properties due to residual potential, etc., and thus shortening the service life. It is short, so it is not practical.

Furthermore, ZnO is susceptible to oxidation-reduction and is significantly affected by the environmental atmosphere, so there is a problem in that it has low reliability in use.

Furthermore, organic photoconductive materials such as PVCz and TNF are suspected to be carcinogens and present human health concerns, and organic materials have low thermal stability and abrasion resistance. , has the disadvantage of short lifespan.

On the other hand, amorphous silicon (hereinafter abbreviated as a-5i:H) has recently attracted attention as a photoconductive conversion material.
Applications to solar cells, thin film transistors, and image sensors are being actively pursued. As part of this application of a-Si:H, a-Si:H is a non-polluting material, so there is no need for recovery treatment, and compared to other materials, it has a high spectral sensitivity in the visible light region. It has advantages such as high surface hardness, excellent wear resistance and impact resistance.

This a-3i:H is being studied as a photoreceptor based on the Carlson method, but in this case, the photoreceptor characteristics required are high resistance and high photosensitivity. Since it is difficult to satisfy the requirements with a single-layer photoreceptor, a layered structure is used in which a barrier layer is provided between the photoconductive layer and the conductive support, and a surface charge retention layer is provided on the photoconductive layer. This satisfies these requirements.

(Problems to be Solved by the Invention) By the way, a-Si+H is usually formed by a glow discharge decomposition method using a silane gas, or at this time,
a-3i: Hydrogen is incorporated into the H film, and the electrical and optical characteristics vary greatly due to the difference in hydrogen content. That is, a-
As the amount of hydrogen that enters the 3i:H film increases, the optical bandgap increases and the resistance of a-3t:H increases, but as a result, the photosensitivity to long wavelength light decreases. For example, it is difficult to use it in a laser beam printer equipped with a semiconductor laser. Furthermore, when the hydrogen content in the a-Si:H film is high, depending on the film forming conditions, those having bonding structures such as (SiH2)n and SiH2 may occupy most of the area in the film. In this case, voids increase and silicon dangling bonds increase, resulting in deterioration of photoconductive properties and rendering the material unusable as an electrophotographic photoreceptor. Conversely, reducing the amount of hydrogen penetrating into a-Si:H reduces the optical band gap and its resistance, but increases the photosensitivity to long wavelength light. However, in conventional a-3i:H produced under normal film formation conditions, when the hydrogen content is low, there is less hydrogen that should be combined with silicon dangling bonds and reduced. For this reason, the mobility of the generated carriers is reduced, the life span is shortened, and the photoconductive properties are deteriorated, making it difficult to use as an electrophotographic photoreceptor.

In addition, as a technique to increase the sensitivity to long wavelength light, there is a technique that generates a film with a narrow optical band gap by mixing silane-based gas and germane GeH4 and decomposing it by glow discharge (in general, silane-based gas Gas and GeH
Since the optimum substrate temperature is different between No. 4 and No. 4, the produced film has many structural defects and cannot be worn out with good photoconductive properties. Further, waste gas treatment of GeH4 is complicated because it becomes a toxic gas when oxidized. Therefore, such technology is not practical.

This invention was made in view of the above circumstances, and has excellent charging ability, low residual potential, high sensitivity over a wide wavelength range up to the near infrared region, and good adhesion to the substrate. An object of the present invention is to provide an electrophotographic photoreceptor having good environmental resistance.

[Structure of the Invention] (Means for Solving the Problems) An electrophotographic photoreceptor according to the present invention is an electrophotographic photoreceptor having an electrically conductive support and an image forming layer formed on the electrically conductive support. In the photoreceptor, the image forming layer has a photoconductive layer including a charge generation layer and a charge transport layer, and the charge transport layer is formed of a semiconductor material made of silicon and at least a part of which is microcrystalline. and the charge generation layer has a laminate in which a layer made of an amorphous material containing silicon as a matrix and a semiconductor layer containing carbon and at least a part of which is microcrystalline are stacked alternately. It is characterized by

(Function) The inventors of the present invention have worked hard to overcome the drawbacks of the prior art described above and to develop an electrophotographic photoreceptor that has both excellent photoconductive properties (electrophotographic properties) and environmental resistance. As a result of repeated experimental research, we came up with the idea that this objective could be achieved by making all or a portion of the charge generation layer have a superlattice structure, and thus completed this invention. be. In this case, this superlattice structure is an extremely thin layer formed by alternately laminating layers made of an amorphous material containing silicon as a matrix and semiconductor layers containing carbon and having microcrystals. Obtainable.

(Embodiments) Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a sectional view of an electrophotographic photoreceptor according to an embodiment of the invention. In FIG. 1, a barrier layer 22 is formed on one side of the conductor support 21, and the barrier layer 22 is
A photoconductive layer 23 is formed on top of the photoconductive layer 2 . Photoconductive layer 23
is a functionally separated type having a charge generation layer 26 and a charge transport layer 25, and has a charge transport layer 25 on a barrier layer 22.
A charge generation layer 26 is formed on the charge transport layer 25. Furthermore, this charge generation layer 26
A surface layer 24 is formed thereon.

The charge generation layer 26 generates carriers upon incidence of light,
One of these carriers neutralizes the charges on the surface of the photoreceptor, and the other carrier travels through the charge transport layer 25 and reaches the conductive support 21 .

In this embodiment, the charge generation layer 26 is constructed by alternately laminating thin layers 31 and 32, as shown in an enlarged cross-sectional view of FIG.

The thin layers 31 and 32 have different optical bandgaps and each have a thickness in the range of 30 to 500 nm. FIG. 2 is an energy band diagram of a superlattice structure in which the horizontal axis represents the thickness direction and the vertical axis represents the optical band gap. In this example, the thin layers 31 and 32 are made of hydrogen-containing microcrystalline silicon (hereinafter referred to as μc-St:H) containing carbon C (hereinafter referred to as μc-SiC).
:H) and amorphous silicon containing hydrogen (abbreviated as a-Si:H).

As shown in Figure 3, although the optical band gap of a-St:H is 1.75 eV and that of μc-SiC:H is 1.6 eV, a-Si:H is a potential barrier. Therefore, μc-3iC:H becomes a potential well.

Therefore, a periodic potential well can be formed by alternately stacking thin layers of μc-SiC:H and thin layers of a-3i:H.

In this way, the optical bandgaps are different from each other′
By stacking four layers, the superstructure has a periodic potential barrier in which the layer with a large optical bandgap acts as a barrier based on the layer with a small optical bandgap, regardless of the size of the optical bandgap itself. A lattice structure is formed.

In this superlattice structure, a large number of carriers are generated by the incidence of light. Therefore, it has high photosensitivity.

Note that by changing the band gap and layer thickness of the thin layer of the superlattice structure, the apparent bandgap of the layer forming the Peter junction superlattice structure can be freely adjusted.

1- As mentioned above, by incorporating C into μc-5i:H, the dark resistance can be increased and the photoconductive properties can be improved. It is believed that C acts as a terminator for silicon dangling bonds and reduces the density of states existing in the forbidden band between bands, thereby increasing the dark resistance.

For a-Si:H and μc-5t:H, hydrogen H was added to 0.0
The content is 1 to 30 atom %, preferably 1 to 25 atom %. This makes silicon dumpling bond? I
The dark resistance and bright resistance are balanced, and the photoconductive properties are improved.

When forming a thin layer by glow discharge decomposition method, H can be added into the thin layer by introducing silane gases such as SiH4 and Si2H6 as raw materials into the reaction chamber and performing glow discharge with high frequency. . Furthermore, when adding C to the thin layer, a hydrocarbon gas such as CH4 is included in the introduced gas.

For μc-3i:H, the temperature of the support is set higher than when forming a-Si:H, and the high-frequency power is also
If the setting is set higher than in the case of , it becomes easier to form. In addition, by increasing the support temperature and high frequency power,
The flow rate of source gas such as silane gas can be increased, and as a result, the film formation rate can be increased. In addition, by using gas obtained by diluting high-order silane gas such as SiH4 and Si2H6 as raw material gas, μc-5
t:H can be formed with higher efficiency.

By the way, μc-Sl is clearly distinguished from a-Si:H and polycrystalline silicon (polycrystalline silicon) due to the following physical characteristics. That is, in the X-diffraction device, since a-Si:H is amorphous, only a halo appears and no diffraction pattern can be observed. Shows a certain crystal diffraction pattern. Further, the polycrystalline silica is formed of a mixed phase of microcrystalline and amorphous particles having a particle size of approximately several tens of angstroms or more.

In order to make μc-Si:H and a-St:H p-type, an element belonging to group Ⅰ of the periodic table, such as boron B1
Aluminum AI, gallium Ga.

It is preferable to dope with indium In, thallium T1, etc., and in order to make the μc-3t:H layer n-type, an element belonging to Group V of the periodic table, such as nitrogen N1
It is preferable to dope with phosphorus P1 arsenic A ss antimony Sb1 and bismuth Bi. By doping the photoconductive layer or the barrier layer with this n-type impurity or n-type impurity, charge migration from the support side to the photoconductive layer is prevented.

On the other hand, silicon halide such as S i F4 gas can be used as the raw material gas. Furthermore, μc-Si:H and a-Si:H can be similarly formed by reacting with a mixed gas of silane gas and silicon halide gas. Note that these thin layers can also be formed by a physical method such as sputtering, instead of using the glow discharge decomposition method. If necessary, hydrogen or helium gas can be used as a carrier gas for silanes.

The charge transport layer 25 is a layer that allows carriers generated in the charge generation layer 26 to reach the support 21 side with high efficiency, and therefore needs to have a long carrier life and high transportability. This charge transport layer 25 is formed using μc-St:H. Thereby, the charge transport layer 25 with good carrier mobility can be formed.

The barrier layer 22 suppresses the flow of charges between the conductive support 21 and the charge generation layer 25, thereby enhancing the charge retention function on the surface of the photoreceptor and increasing the charging ability of the photoreceptor. In the Carlson method, when the surface of the photoreceptor is positively charged, the barrier layer is made p-type in order to prevent electrons from being injected from the support side to the charge generation layer. On the other hand, when the photoreceptor surface is negatively charged, in order to prevent holes from being injected from the support side to the charge generation layer,
Make the barrier layer n-type. It is also possible to form an insulating film on the support as a barrier layer. The barrier layer is μ
It may be formed using c-3i:H, or a-3i:
It is also possible to form using H. In this case,
A high-resistance insulating barrier layer can be formed by incorporating at least one element selected from carbon, C, nitrogen, and zero oxygen into μc-St:H or a-Si:H. The thickness of the barrier layer 22 is 100 to 10
μm is preferred.

A surface layer 24 is provided on the charge generation layer 26. Since a-3iC:H and the like of the charge generation layer 26 has a relatively large refractive index of 3 to 3.4, light reflection easily occurs on the surface. When such light reflection occurs, the proportion of the amount of light absorbed by the photoconductive layer 23 or the charge generation layer 26 decreases, increasing optical loss. For this reason, it is preferable to provide the surface layer 24 to prevent reflection. Further, by providing the surface layer 24, the charge generation layer 26 is protected from damage.

Furthermore, by forming the surface layer 24, the charging ability is improved, and charges can be easily deposited on the surface.

Materials for forming the surface layer 24 include a-SiN:H,
There are inorganic compounds such as a-SiO:H, and a-3iC:H, and six-layer materials such as polyvinyl chloride and holamide.

When the surface of the electrophotographic photoreceptor constructed in this way is charged with a positive voltage of approximately 500 V by corona discharge, for example, in the case of the functionally separated electrophotographic photoreceptor shown in FIG. As shown, a potential barrier is formed.

When light (hν) is incident on this photoreceptor, the charge generation layer 26
Electron and hole carriers are generated in the superlattice (1'4 structure).The electrons of this conductor are accelerated toward the surface layer 24 side by the electric field in the photoreceptor, and the holes are 21 side. In this case, the number of carriers generated at the boundaries of thin layers with different optical band gaps is much larger than the number of carriers generated in the bulk. The structure has high photosensitivity.Also, due to quantum effects in the potential well layer, the lifetime of carriers is 5 to 10 times longer than in the case of a single layer that is not a superlattice. In the lattice structure, there is a discontinuity in the band gap, and a periodic barrier layer is formed, but carriers easily pass through the bias layer due to the tunnel effect, so the effective mobility of carriers is equivalent to that in the bulk. As described above, the superlattice structure in which thin layers with different optical band gaps are laminated can provide high photoconductivity, and is superior to conventional photosensitive materials. It is possible to obtain a clearer image than that of the body.In addition, this superlattice structure reduces distortion between each layer, making it difficult for layers to peel off and improving adhesion to the substrate.

FIG. 4 is a diagram showing an apparatus for manufacturing an electrophotographic photoreceptor according to an embodiment of the present invention by a glow discharge method. For example, the gas cylinders 1, 2, 3, and 4 contain SiH4 and B, respectively.
2 H6, H2, He, CHt.

A raw material gas such as N2 is contained. The gas in these gas cylinders 1, 2, 3.4 is supplied to a mixer 8 via a valve 6 and piping 7 for flow rate adjustment. Each cylinder is equipped with a pressure gauge 5, and by monitoring the pressure gauge 5 and regulating the valve 6, the flow rate and mixing ratio of each raw material gas supplied to the mixer 8 can be adjusted. Can be done. The gases mixed in the mixer 8 are supplied to a reaction vessel 9. A rotating shaft 10 is attached to the bottom 11 of the reaction vessel 9 so as to be rotatable around the vertical direction, and a disk-shaped support 12 is attached to the upper end of the rotating shaft 10 with its surface perpendicular to the rotating shaft 10. It has been fixed. Inside the reaction vessel 9, a cylindrical electrode 13 is installed on the bottom 11 with its axial center aligned with the axial center of the rotating shaft 10. A drum base 14 of a photoreceptor is placed on a support base 12 with its axial center aligned with the axial center of the rotating shaft 10, and a heater 15 for heating the drum base is arranged inside the drum base 14. It is set up. A high frequency power source 16 is connected between the electrode 13 and the drum base 14, and the electrode 13
A high frequency current is supplied between the drum base 14 and the drum base 14. The rotating shaft 10 is rotationally driven by a motor 18. The pressure inside the reaction vessel 9 is monitored by a pressure gauge 17, and the reaction vessel 9 is connected via a gate valve 18 to an appropriate evacuation means such as a vacuum pump.

When manufacturing a photoreceptor using an apparatus configured as described above, after installing the drum base 14 in the reaction vessel 9, the gate valve 19 is opened to increase the inside of the reaction vessel 9 to approximately 0.1 Torr. Evacuate to a pressure below r). Next, the required reaction gases from the cylinders 1, 2, 3, and 4 are mixed at a predetermined mixing ratio and introduced into the reaction vessel 9. In this case, the amount of gas EE introduced into the reaction vessel 9 is set so that the pressure within the reaction vessel 9 is 0.1 to 1 Torr. Next, the motor 18 is operated to rotate the drum base 14, the heater 15 heats the drum base 14 to a constant temperature, and the high frequency power supply 16 supplies high frequency current between the electrode 13 and the drum base 14. A glow discharge is formed between the two. As a result, a-3i:H or μc-3i:H is deposited on the drum base 14. In addition, N in the raw material gas
20°NH3, NO2, N2. CH,,C2H,,o2
By using gas etc., these elements can be converted to a-St.
:H or μc-3i:H.

As described above, since the electrophotographic photoreceptor according to the present invention can be manufactured using a closed system manufacturing apparatus,
Safe for humans. Furthermore, this electrophotographic photoreceptor has excellent heat resistance, moisture resistance, and abrasion resistance, so it has the advantage of having a long lifespan with little deterioration even after repeated use over a long period of time.

Furthermore, since a long wavelength sensitizing gas such as G e Ha is not required, there is no need to provide waste gas treatment equipment, and industrial productivity is extremely high.

In this example, a-3i:H was used as one of the thin layers constituting the charge generation layer, but a-SiC:H in which C is added may also be used.

Next, the results of testing the electrophotographic properties of an electrophotographic photoreceptor according to the present invention formed into a film will be described.

Test Example 1 If necessary, to prevent interference, an aluminum drum base with a diameter of 80 mm and a length of 350 mm, which has been subjected to acid treatment, alkali treatment, and sandblasting, is installed in the reaction vessel. was evacuated to a vacuum level of about 10 JJ Torr using a diffusion pump (not shown). Thereafter, the drum base was heated to 350°C and rotated at 1 o rpm, and SiH4 gas was heated at 500SCCM, B21 (, gas was heated at a flow rate ratio of 10-6, CH to SiH4 gas flow rate).
4 gases were introduced into the reaction vessel at a flow rate of 11005 cc, and the inside of the reaction vessel was adjusted to 1 torr.

Then, a high frequency power of 13.56 MHz is applied to the electrode to generate plasma of SiH4゜B2H6 and CH between the electrode and the drum base, and p-type a-SiC:H
A barrier layer was formed.

Next, SiH4 gas was added at 150 SCCM.

CH, gas was introduced into the reaction vessel at a flow rate of 1200 SCCM, the inside of the reaction vessel was set at 1.5 Torr, and IKW high frequency power was applied to form a charge transport layer consisting of a 10 μm i-type μc-3i:H. Formed.

After that, the discharge is temporarily stopped and the SiH4 gas is
005CC, gas 5SCCM, H2 gas 1200S
It was introduced into the reaction vessel at a flow rate of CCM, and the reaction pressure was set at 1.
．． Adjusted to 8 torr. Then, a high frequency power of 1.2 KW was applied to form a thin layer of 50 μc-SiC:H. Next, the flow rates were set to 500 SCCM for SiH4 gas and 750 S CCM for H2 gas, and B2H6/S
By setting the flow rate of B2H6 so that the iH4 ratio is 10-7 and applying 500W of high frequency power, 50
A thin layer of human a-3t:H was formed. By repeating these operations, 250 μC-3iC:H thin layers and 250 a-Si:H thin layers were alternately laminated to form a charge generation layer with a 5 μm heterojunction superlattice structure. . Then 0.1
A surface layer of .mu.m a-SiC:H was formed. In addition, μC
The crystallinity and grain size of the -3iC:H thin layer are each 60
% and 50 people.

When the surface of the photoreceptor thus formed is positively charged at about 500 V and exposed to white light, this light is absorbed by the charge generation layer and carriers of electron-hole pairs are generated. In this test example, a large number of carriers were generated, the carrier life was long, and high running performance was obtained. This resulted in clear, high-quality images. In addition, when the photoreceptor manufactured in this test example was repeatedly charged, the reproducibility and stability of the transferred image were extremely good, and the durability such as corona resistance, moisture resistance, and abrasion resistance was also improved. has been proven to be superior. Further, the photoreceptor manufactured in this manner has high sensitivity even to a long wavelength of 780 to 790 layers, which is the oscillation wavelength of a semiconductor laser. When this photoreceptor was installed in a semiconductor laser printer and an image was formed by the Carlson process, a clear, high-resolution image could be obtained even when the exposure amount of the photoreceptor was 25 erg/i. In addition, even when exposed to normal light, when this photoreceptor is repeatedly charged in the same way as when exposed to white light, the transferred image has high reproducibility and stability, and has excellent corona resistance, moisture resistance, abrasion resistance, etc. It had excellent durability.

Test Example 2 In this test example, the barrier layer was p-type μC-5iC:
) The layer structure was the same as in Test Example 1, except for I. In this case, SiH4 gas is 100S1005CC gas is 1500SCCM, CH4 gas is 20S CCM,
B2H6 gas was introduced into the reaction vessel with the flow rate set so that B2H6/SiH4 was 1X10-2, the reaction pressure was 1.5 Torr, 1.2 KW of high frequency power was applied, and a 0.5 μm thin film was introduced. formed a layer. The crystallinity and grain size of this layer were 65% and 70%, respectively.

When the electrophotographic photoreceptor thus formed was mounted on a semiconductor laser printer and images were formed by the Carlson process, clear, high-resolution images could be obtained in all cases. In addition, when repeatedly charged,
In all cases, it was demonstrated that image reproducibility and stability were high, and durability such as corona resistance, moisture resistance, and abrasion resistance was excellent.

Test Example 3 In this test example, the charge transport layer contains C and μ
Other layers were formed under the same conditions as Test Example 1 except that c-3iC:H was used. In this case, SiH4 gas is 11005
CC, H2 gas at 1200SCCM, CH4 gas at IS
It was introduced into the reaction vessel at a flow rate of CCM, and the reaction pressure was set at 1.
．． A high frequency power of 1.2 KW was applied at 6 torr.

As a result, the surface potential was improved by about 20% compared to Test Example 1.

In addition, in these test examples, the thickness of the charge transport layer was
Although the thickness is not limited to this, it is also possible to set the thickness to 1 or 3 μm for practical use as a photoreceptor.

[Effects of the Invention] According to the present invention, at least a portion of the charge generation layer is a laminate of an amorphous layer containing silicon as a matrix and a semiconductor layer containing carbon and at least a portion of which is microcrystalline. Electrophotography uses a superlattice structure composed of 100% lattice, has high sensitivity in a wide wavelength range from visible light to near-infrared light, has high carrier mobility, and has high resistance and excellent charging characteristics. A photoreceptor can be obtained. Furthermore, by forming at least a portion of the charge generation layer into a superlattice structure in this manner, distortion between the layers can be reduced, and adhesion with the substrate can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an electrophotographic photoreceptor according to an embodiment of the present invention, FIG. 2 is a partially enlarged sectional view of FIG. 1, FIG. 3 is a diagram showing energy bands of a superlattice structure, and FIG. The figure shows an apparatus for manufacturing an electrophotographic Q photoreceptor according to an embodiment of the present invention, and FIG. 5 is a schematic diagram showing the energy gap of the photoreceptor. 1.2, 3, 4; Cylinder, 5; Pressure gauge, 6; Valve, 7
; Piping, 8; Mixer, 9; Reaction container, 10; Rotating shaft, 1
3; electrode, 14; drum base, 15; heater, 16; high frequency power supply, 19; gate valve, 21; conductive support,
22; barrier layer, 23; photoconductive layer, 24; surface layer, 25;
71! Charge transport layer, 26; charge generation layer, 31, 32; thin layer. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4

Claims (8)

[Claims] (1) In an electrophotographic photoreceptor having a conductive support and an image forming layer formed on the conductive support, the image forming layer is a photoconductive layer comprising a charge generation layer and a charge transport layer. The charge transport layer is formed of a semiconductor material having silicon as a matrix and at least a part of the semiconductor material is microcrystalline, and the charge generation layer is made of an amorphous material having silicon as a matrix. 1. An electrophotographic photoreceptor comprising a laminate in which layers and semiconductor layers containing carbon and at least a portion of which are microcrystalline are alternately stacked. (2) Each layer constituting the charge generation layer has a density of 30 to 50
The electrophotographic photoreceptor according to claim 1, having a layer thickness of 0 Å. (3) The electrophotographic photoreceptor according to claim 1 or 2, wherein the amorphous material contains carbon. (4) The image forming layer is formed on a conductor and has a barrier layer made of an amorphous layer with silicon as a matrix or a semiconductor layer in which at least a part of the layer is microcrystalline. An electrophotographic photoreceptor according to claim 1. (5) The photoconductive layer according to any one of claims 1 to 3, wherein the photoconductive layer contains an element belonging to group III or group V of the periodic table. Electrophotographic photoreceptor. (6) The electrophotographic photoreceptor according to claim 4, wherein the barrier layer contains an element belonging to Group III or Group V of the periodic table. (7) The electrophotographic photoreceptor according to claim 4 or 6, wherein the barrier layer contains at least one element among carbon, oxygen, and nitrogen. (8) The image forming layer has a surface layer formed on the photoconductive layer.
The electrophotographic photoreceptor described in .