JPS6239875A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body superior in electrostatic chargeability, sensitivity, and resistance to ambient conditions, low in residual potential, and good in adhesion by laminating on a conductive substrate a barrier layer, a photoconductive layer specified in thickness and composed of an muC-Si layer and an a-Si layer, and a surface layer, and incorporating specified elements in these layers. CONSTITUTION:A gas mixture of SiH4, B2H6, N2, CH4, etc., in a specified composition is decomposed by the glow discharge method and the barrier layer 22 made of muC-Si or a-Si, the photoconductive layer 31 composed of the muC-Si layer 23 and the a-Si layer 24, and the a-Si surface layer 25 are formed on the conductive substrate 21. The layer 31 has a layer thickness of 1-80mum and the layer 24 and has a layer thickness of <=5mum. At least one of elements of groups III and V and C, N, and O is incorporated in the layer 22, and at least one of C, N, and O is incorporated in the surface layer 25. Light transmittance is enhanced by reducing the layer thickness of the layer 24, and an amount of carriers to be generated is increased by increasing the layer thickness of the photoconductive layer 31 to about 30mum to enhance photosensitivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electrophotographic photoreceptor having excellent charging characteristics, photosensitivity characteristics, environmental resistance, etc.

[Technical background of the invention and its problems] Conventionally, as a material for forming a photoconductive layer of an electrophotographic photoreceptor, Cd S S Z n Os Se Se Se Se
Inorganic materials such as T e or amorphous silicon or poly-N-vinylcarbazole (PVCz) or trinitrofluorene (TNF)
Organic materials such as However, these conventional photoconductive materials have various problems in photoconductive properties and manufacturing, and these materials can be modified depending on the purpose of use at the expense of some of the properties of the photoreceptor system. are used differently.

For example, Se 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 needs to be recovered, which adds to the recovery cost. Also,
For Se or 5e-Te systems, the crystallization temperature is 65°C.
Therefore, during repeated copying, problems with the photoconductive properties arise due to residual frost, etc., resulting in a short life span and low practicality.

Furthermore, ZnO is susceptible to oxidation-reduction and is significantly affected by the environmental atmosphere, so there are problems in that its use and reliability are low.

Furthermore, organic photoconductive materials such as PVCz and TNF are suspected carcinogens and pose a health risk to humans.
1- In addition to the problems, organic materials have the disadvantage of low thermal stability and wear resistance, and short life span.

On the other hand, amorphous silicon (hereinafter abbreviated as a-8i)
has recently attracted attention as a photoconductive conversion material, and is being actively applied to solar cells, thin film transistors, and image sensors. As part of the application of A-8i, attempts have been made to use A-8T as a photoconductive material for electrophotographic photoreceptors, and photoreceptors using A-8L are recycled because they are non-polluting materials. No processing required;
Compared to other materials, it has advantages such as high spectral sensitivity in the visible light region, high surface hardness, and excellent wear resistance and impact resistance.

This a-8i is being studied as a photoreceptor based on the Carlson method, but in this case, the photoreceptor characteristics are required to be high resistance and photosensitivity. Since it is difficult to satisfy the requirements with a photoreceptor, a layered structure is created 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. It satisfies these demands.

By the way, a-8i is usually formed by a glow discharge decomposition method using silane gas, but at this time, a-8i is
Hydrogen is incorporated into the 8t film, and the electrical and optical characteristics vary greatly due to the difference in the amount of hydrogen. That is, as the amount of hydrogen mixed into the a-8t film increases, the optical bandgap increases and the resistance of a-3i 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. In addition, if the hydrogen content in the a-8i film is high, depending on the film formation conditions, (Si
Those having a bonding structure such as H2)+z 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-8i reduces the optical band gap and its resistance, but increases photosensitivity to long wavelength light. However, when the hydrogen content is low, there is less hydrogen to combine with silicon dangling bonds and reduce them.This reduces the mobility of the generated carriers, shortens the lifetime, and reduces the photoconductivity. The properties deteriorate, making it difficult to use as an electrophotographic photoreceptor.

As a technique to increase the sensitivity to long wavelength light, there is a method of mixing silane-based gas and germane GeH4 and performing glow discharge decomposition to produce a film with a narrow optical bandgap. and GeH4
Since the optimum substrate temperature is different between the two methods, the produced film has many structural defects and cannot obtain 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.

[Object of the Invention] The present 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 It is an object of the present invention to provide an electrophotographic photoreceptor that has good adhesion to the substrate and excellent environmental resistance.

[Summary of the Invention] An electrophotographic photoreceptor according to the present invention includes an electrically conductive support and a photoconductive layer formed on the electrically conductive support, wherein the photoconductive layer is amorphous. A first layer made of silicon and a second layer made of microcrystalline silicon are laminated, and the layer thickness of this photoconductive layer is 1 to 80 μm, and the layer thickness of the first layer is It is characterized by being 5 μm or less.

The present invention was achieved by the inventors of the present invention, who have conducted various experimental studies in order 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, microcrystalline silicon (hereinafter referred to as μ
The present invention was completed based on the idea that this object could be achieved by using C-3i (abbreviated as C-3i) for at least a portion of an electrophotographic photoreceptor.

[Embodiments of the Invention] The present invention will be specifically described below. The feature of this invention is that μC-8i is used instead of the conventional a-8i. That is, whether all or some regions of the photoconductive layer are formed of microcrystalline silicon (μC-8T) or a mixture of microcrystalline silicon and amorphous silicon (a-8i); Alternatively, it is formed of a laminate of microcrystalline silicon and amorphous silicon. In addition, in a functionally separated electrophotographic photoreceptor, μ is added to the charge generation layer.
I am using C-8t.

μC-8i is a-
8t and polycrystalline silicon (polycrystalline silicon)
clearly distinguished from That is, in X-ray diffraction measurement, since a-3i is amorphous, only a halo appears;
Although no diffraction pattern can be observed, μC-8t shows a crystal diffraction pattern with a 2θ of around 27 to 28.5°. Also, while polycrystalline silicon has a dark resistance of 106Ω, μC-8t has a dark resistance of 1011Ω.
・Has dark resistance on closing breath. This μC-8t is formed by an aggregation of microcrystals having a particle size of about a few angstroms or more.

A mixture of μC-8i and a-8i is a mixture of μC-3i crystal regions mixed in a-8i, and μC-8i and a-8i.
-8t is present in the same volume ratio. Also,
The laminate of μC-8i and a-8t is mostly a-8
A layer consisting of i and a layer filled with μC-5i are laminated.

Similar to a-8i, a photoconductive layer containing μC-8i can be produced by depositing μC-8i on a conductive support using silane gas as a raw material using a high-frequency glow discharge decomposition method. can. In this case, if the temperature of the support is set higher than when forming a-5t and the high frequency power is also set higher than when forming a-8i, μC
-3i becomes easier to form. Furthermore, by increasing the support temperature and high frequency power, the flow of source gas such as silane gas can be increased, and as a result, the film formation rate can be increased. Further, by using a gas obtained by diluting a high-order silane gas such as SiH4 and 5i2He as a raw material gas with hydrogen, μC-8i can be formed with higher efficiency.

= 9 - FIG. 1 is a diagram showing an apparatus for manufacturing an electrophotographic photoreceptor according to the present invention. For example, the gas cylinders 1 and 2°3.4 contain SiH+ and B2Hs, respectively.

Source gases such as H2 and CH4 are 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 adjusting the valve 6, the flow rate and mixing ratio of each raw material gas supplied to the mixer 8 can be adjusted. can. The gases mixed in the mixer 8 are supplied to a reaction vessel 9. A rotary shaft 0 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 -L end of the rotary shaft 10 so that its surface is the rotary shaft. It is fixed perpendicular to 10. 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-L with its axial center aligned with the axial center of the rotating shaft 10, and a heater 15 for heating the drum base is installed inside the drum base 14. It is arranged. 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 the apparatus configured as described above, after installing the drum base 14 in the reaction vessel 9, the gate valve 19 is opened to control the inside of the reaction vessel 9 at approximately 0.1 Torr. Evacuate to below pressure. Next, cylinder 1
, 2, 3.4 are mixed at a predetermined mixing ratio and introduced into the reaction vessel 9. In this case, reaction vessel 9
The gas flow rate introduced into the reaction vessel 9 is such that the pressure inside the reaction vessel 9 is 0.1.
Set it so that it is between 1 Torr and 1 Torr. Next, the motor 18
to rotate the drum base 14, = 11
= The drum base 14 is heated to a constant temperature by the heater 15, and the electrode 13 and the tram base 1 are heated by the high frequency power supply 16.
4, a high frequency current is supplied between the two to form a glow discharge between the two. As a result, microcrystalline silicon (μC-3i) is deposited on the drum base 14''. Note that N20. NH3, NO2, N2, C
These elements can be contained in μC-8i by using H4°C2H4,02 gas or the like.

In this way, the electrophotographic photoreceptor according to the present invention has a conventional a
Similar to those using -8t, it can be manufactured using closed system manufacturing equipment, so it is safe for the human body. 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 GeHa is not required, there is no need to provide waste gas treatment equipment, and industrial productivity is extremely high.

= 12 = Preferably, μC-8i contains 0.1 to 30 atomic % of hydrogen. As a result, the dark resistance and bright resistance become harmonious, and the photoconductive properties are improved. μC-
The optical energy gap EC of 3t is the optical energy gap EC of a-8i (1.65 to 1.70 eV)
small compared to In other words, the optical energy gap of μC-8t changes depending on the grain size and crystallinity of μC-8i microcrystals, and as the grain size and crystallinity increase,
Its optical energy gap decreases to approach that of crystalline silicon, 1.1 eV. By the way, the μC-8i layer and the a-81 layer absorb light with a larger energy than this optical energy gap, and transmit light with a smaller energy. Therefore, a-8i absorbs only visible light energy, but μC-8i, which has a smaller optical energy gap than a-8i, can also absorb near-infrared light, which has a longer wavelength and lower energy than visible light. I can do it. Therefore, μC-8i has high photosensitivity over a wide wavelength range.

= 13 - μC-8i having such characteristics is suitable as a photoreceptor material for a laser printer using a semiconductor laser as a light source. When this a-3i is used as a photoreceptor for a laser printer, the light wavelength of the semiconductor laser is 790 nm.
Since 8i is longer than the wavelength range in which it is highly sensitive, the sensitivity of the photoreceptor becomes insufficient, and therefore it is necessary to apply a laser intensity to the photoreceptor that exceeds the ability of the semiconductor laser, making it difficult to put into practical use.
-There is a problem. On the other hand, when the photoreceptor is formed from μC-8i, its high sensitivity region extends to the near-infrared region, so that it is possible to obtain a photoreceptor for semiconductor laser printers with extremely excellent photosensitivity characteristics.

In order to further improve the photoconductive properties of μC-8t, which has such excellent photosensitivity characteristics, it is preferable to incorporate hydrogen into μC-8i.

Doping hydrogen into the μC-8i layer is performed, for example, by glow discharge decomposition, by introducing a silane-based raw material gas such as 5iHa and Si2H6 and a carrier gas such as hydrogen into a reaction vessel and causing glow discharge. or SiF4 and 5
A mixed gas of silicon halide such as iC14 and hydrogen gas may be used, or a mixed gas of silane-based gas and silicon halide may be used. Furthermore, the μC-8i layer can be formed not only by the glow discharge decomposition method but also by a physical method such as sputtering.

Note that the leading conductive layer containing μC-8i has 1
It is preferable to have a film thickness of 80 μm to 80 μm, and more preferably 5 to 50 μm.

Substantially all regions of the photoconductive layer may be formed of μC-8i, or may be formed of a mixture or a laminate of a-8i and μC-8t. The charging ability is higher in the laminate, and the photosensitivity is higher in the long wavelength region of the infrared region, although it depends on the volume ratio, in the mixture, and in the visible light region, the two are almost the same.

Therefore, depending on the use of the photoreceptor, substantially all the regions may be made of μC-8i, or may be made of a mixture or a laminate.

Preferably, μC-8i is doped with at least one element selected from nitrogen, nitrogen, carbon, and oxygen. Thereby, the dark resistance of μC-5i can be increased and the photoconductive properties can be improved.

These elements precipitate at the grain boundaries of μC-8i and act as terminators for silicon dangling bonds,
It is thought that the density of states existing in the forbidden heat between the bands is reduced, thereby increasing the dark resistance.

Preferably, a barrier layer is provided between the conductive support and the photoconductive layer. This barrier layer enhances the charge retention function on the surface of the photoconductive member by suppressing the flow of charge between the conductive support layer and the photoconductive layer, and improves the charging ability of the photoconductive member. Increase.

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 photoconductive layer. On the other hand, when the photoreceptor surface is negatively charged, a barrier layer is formed to prevent holes from being injected from the support side to the photoconductive layer.
Make it into a mold. It is also possible to form an insulating film on the support 1- as a barrier layer. Barrier layer is μC-8i
It is also possible to form the barrier layer using [7, a-5i].

In order to make μC-5t and a-5t p ifν,
Elements belonging to the 'JTIT group of the periodic table, such as boron B1 aluminum AI, gallium Ga, indium In
It is preferable to dope with , thallium T1, etc., and in order to make the μC-8i layer n-type, doping with
Elements belonging to the group, such as nitrogen N1 phosphorus P1 arsenic As,
It is preferable to dope with antimony sb1, bismuth 81, or the like.

Doping with this n-type impurity or n-type impurity prevents charge from moving from the support side to the photoconductive layer.

Preferably, a surface layer is provided on top of the photoconductive layer.

Since μC-8t of the photoconductive layer has a relatively large refractive index of 3 to 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 decreases, increasing optical loss. For this reason, it is preferable to provide a surface layer to prevent reflection. Also, by providing a surface layer, the photoconductive layer is protected from damage. Furthermore, by forming the surface layer, the charging ability is increased to -1, and the charge is more easily deposited on the surface. The material forming the surface layer is Si3 N4.5io2, SiC.

Al103, a-8iN; H, a-8iO; H.

and a-8iC;H, and organic materials such as polyvinyl chloride and polyamide.

As described above, a photoconductive member applied to an electrophotographic photoreceptor is formed by forming a barrier layer on a support, a photoconductive layer on this barrier layer, and a surface layer on this photoconductive layer. charge transport layer (CTL) on the support
It is also possible to form a functionally separated structure in which a charge generation layer (CGL) is formed between the charge transfer layer and the charge transfer layer. In this case, a barrier layer may be provided between the charge transfer layer and the support. The charge generation layer generates carriers upon irradiation with light. The charge generation layer is preferably made of microcrystalline silicon μC-8T in part or in its entirety, and has a thickness of 1 to 10 μm. The charge transfer layer is a layer that allows carriers generated in the charge generation layer to reach the support side with high efficiency,
For this reason, it is necessary for the carrier to have a long life, high mobility, and high transportability. The charge transport layer can be formed of μC-5t. In order to increase the dark resistance and improve the charging ability, it is preferable to light-dope an element that belongs to either Group Ⅰ or Group V of the periodic table. Furthermore, in order to further improve the charging ability and to have the functions of both a charge transfer layer and a charge generation layer, one or more of the elements C, N, and 0 may be contained.

If the charge transport layer is too thin or too thick, it will not function satisfactorily. Therefore, the thickness of the charge transport layer is preferably 3 to 80 μm.

By providing a barrier layer, even in a functionally separated type photoreceptor having a charge transfer layer and a charge generation layer, its charge retention function and charging ability can be improved. In addition,
Whether the barrier layer is p-type or n-type is determined depending on its charging characteristics. This barrier layer may be formed of a-8i or μC-3i.

A feature of the invention according to this application is that the photoconductive layer is constructed by laminating a first layer made of amorphous silicon and a second layer made of microcrystalline silicon. The layer thickness is 1 to 80 μm, and the layer thickness of the first layer is 5 μm or less. 2 to 6 are cross-sectional views of an electrophotographic photoreceptor embodying the present invention. In FIG. 2 or 3, a barrier layer 22 is formed on a conductive support 21, a photoconductive layer 31 or 32 is formed on the barrier layer 22, and a photoconductive layer 31 or 32 is formed on the photoconductive layer 31 or 32. A surface layer 25 is formed. In the photoreceptor shown in FIG. 2, the photoconductive layer 31 is a-8t on the surface layer 25 side.
and μC-8i on the barrier layer 22 side.
In the photoreceptor shown in FIG. 3, the first layer 24 formed from a-8t of the photoconductive layer 32 is formed on the barrier layer 22 side. The second layer 23 made of μC-8i is formed on the surface layer 25 side. Further, in the photoreceptor shown in FIG. 4, a charge retention layer 26 is provided between the barrier layer 22 and the photoconductive layer 31.
In the photoreceptor shown in FIG. 5, a charge retention layer 26 is formed between the photoconductive layer 31 and the surface layer 25.

On the other hand, in the photoreceptor shown in FIG. 6, charge retention layers 26 and 27 are formed between the barrier layer 22 and the photoconductive layer 31 and between the photoconductive layer 31 and the surface layer 25, respectively.

The photoconductive layer 31 or 32 or the first layer 24 of a-8t and μ
Since it is a laminate with the second layer 23 of C-8i, it is possible to increase the sensitivity of the electrophotographic photoreceptor from the visible light region to the near-infrared region (for example, around 790 nm, which is the oscillation wavelength of a semiconductor laser). I can do it. That is, the optical band gap of μC-8i is usually 1.4 to 1.65 eV, and a-8
The optical bandgap of t is typically 1.6 to 1.8 eV
It is. Therefore, visible light is absorbed by the a-8i layer, while long wavelength light such as near-infrared light is absorbed with high efficiency by the μC-8i layer. Therefore, since the photoreceptor according to the present invention has high spectral sensitivity over a wide wavelength range from visible light to near-infrared light, this photoreceptor can be used in both PPCs (plain paper copiers) and laser printers. It is possible to use.

The layer thickness of this photoconductive layer is 1 to 80 μm.

This is because when the layer thickness of the photoconductive layer is thin, its volume becomes small and fewer carriers are generated, which deteriorates the photoconductivity.If the layer thickness is too thick, light is trapped inside the photoconductive layer. This is because the carrier does not penetrate sufficiently and does not cut through the conductive support, so the carrier accumulates and the residual potential becomes high. For these reasons, the thickness of the photoconductive layer needs to be within the above range, preferably from 5 to 50 μm. Note that when the photoreceptor is used in a laser printer, the layer thickness of the photoreceptor is relatively thick, for example, 30 μm. This is because the longer the wavelength, the higher the transmittance of light, so even if the layer thickness is increased, the long wavelength light will be sufficiently transmitted.As the layer thickness is increased, the amount of carriers generated will increase. This is because the photosensitivity becomes higher.

In the case of PPC, the photoconductive layer is thinner than in the case of laser printers.

The first layer 24 of photoconductive layer A-8L has a thickness of 5 μm or less, preferably 1 to 4 μm. a-8i
This is because if it is too thick, it will be difficult to increase the photosensitivity on the long wavelength side. A first layer consisting of a-8t and μC-8i
The ratio to the second layer made of μC-8i may be selected appropriately depending on the purpose of use of the photoreceptor. By making the layer thicker than the first layer of a-8i, the photosensitivity can be increased.

μC-8i itself is somewhat n-type, but this μC-8
By lightly doping (10-7 to 10-3 atomic %) the second layer consisting of i with an element belonging to group Ⅰ of the periodic table, the μC-8 bilayer becomes an n-type (intrinsic) semiconductor, The dark resistance becomes high, and the SN ratio and charging ability become -1. Also,
When the second layer made of μC-8i and the first layer made of a-3i contain at least one element selected from C10°N, the photoconductive layer 31 or 32 is further Dark resistance can be increased and charging ability can be improved. In this case, the content of C, 0, H is 0.01 to 2
The content is 0 atomic %, preferably 0.1 to 10 atomic %.

Barrier layer 22 can be formed of a-8i or μc-8i. Preferably, this barrier layer 22 also contains 10@-3 to 96 atoms of an element belonging to Group 1 or Group V of the periodic table. Furthermore, the barrier layer 22 contains at least one element among C, O, and N at 1 to 30 atomic %.
When the content is within this range, the blocking ability of the carrier is further improved, which is preferable from the viewpoint of electrophotographic properties. The layer thickness of the barrier layer 22 is 0.01 to 15 μm1, preferably 0.01 to 15 μm1.
．． It is 1 to 2 μm. If the thickness of the barrier layer is too thick, the blocking ability will not be as good, and there will be a disadvantage that carriers will easily remain and the residual potential will increase. On the other hand, if the barrier layer is too thin, This is because sufficient blocking ability cannot be obtained.

The surface layer 25 contains at least one of C, O, and N.
It is formed of a-8i containing an element of 1-. This protects the surface of the photoconductive layer, improves corona ion resistance and environmental resistance, and improves charging ability.

The charge retention layers 26 and 27 are formed by a-8i containing at least one element selected from elements belonging to Group 1 of the periodic table, C, 0, and N. This increases the dark resistance of a-8i, and by forming a layer with such high dark resistance between the photoconductive layer 31 and the surface layer 25 or the barrier layer 22, the charging ability of the electrophotographic photoreceptor is improved. , electrostatic properties such as charge retention ability and surface potential during repeated fatigue can be significantly improved.

The elements of group Ⅰ or group V of the periodic table or C, O, and N contained in each layer may be distributed in the layer so that the content thereof changes continuously in the thickness direction. Thereby, when the content of the doping element in each layer is different, it is possible to prevent a sudden change in the concentration distribution at the interface. Therefore, when the photoreceptor is used repeatedly, carriers are trapped at the interface and residual potential increases.
It is possible to prevent the electrophotographic characteristics from deteriorating due to the increase in temperature. Note that these doping elements may be contained only in the vicinity of the interface between each layer.

Next, embodiments of the invention will be described.

Example 1 This example concerns a photoreceptor for positive charging.

An Al drum serving as a conductive substrate was loaded into a reaction container, and the inside of the reaction container was evacuated by a diffusion pump (not shown).
Create a vacuum of approximately 10-5 torr. Thereafter, the drum base is heated and maintained at about 290°C. Next, B2 gas with a flow rate ratio of 10-2 to the flow rate of SiH4 gas and 5iHa gas
H[i gas and 150% N2 and CH4 mixed gas of 5iHa gas were mixed and supplied to the reaction vessel. Then, a high frequency power of 100 watts was applied at a reaction pressure of 0.4 Torr to generate plasma between the electrode and the drum substrate, and the film was formed for 30 minutes to form a barrier layer. Then,
B2 H[i flow rate ratio to SiH4 is 10-8, H
2 gas and N2 gas together to 50%, reaction pressure 0.6
The high frequency power was set at 360 watts, and the film was formed for 6 hours. As a result, a μC-8i layer with a thickness of 15 μm was formed.
Its grain size was 40. Next, the flow rate ratio of B2 H6 to SiH4 is set to lXl0-6, N2 and CH
The film was formed for 3 hours using a total of 4 gases of 15%, a reaction pressure of 0.4 torr, and a high frequency power of 100 watts. As a result, an a-8i layer having a thickness of 5 μm was formed. Then, CHa
The gas was 10 times the SiH4 gas flow rate, and the reaction pressure was 0.
．． The film was formed at a pressure of 4 torr for 10 minutes. As a result, a surface layer was formed, and the total thickness of the barrier layer, photoconductive layer, and surface layer was 23 μm.

When a voltage of 6.5 kV was applied by corona discharge to the photoreceptor thus formed, a surface potential of 400 V was obtained, and the charge retention rate after 15 seconds was 60%. Furthermore, when this photoreceptor drum was attached to a copying machine and an image was produced, an extremely excellent image with high resolution, high contrast, and no fogging was obtained. Furthermore, even after repeated use 100,000 times, images were obtained that were as clear as the initial images.

Example 2 A photoreceptor was manufactured by reversing the formation order of the a-5i layer and μC-8i layer in the photoconductive layer from that in Example 1. That is, each layer was formed in this order: the substrate, the barrier layer, the a-8i layer, the μc-si layer, and the surface layer.

In this example as well, when the photoreceptor was installed in a copying machine, extremely excellent images were obtained as in Example 1.

Example 3 A negative charging photoreceptor drum was manufactured by changing the B2 H6 gas used in forming the barrier layer and photoconductive layer in Example 1 to PH3 gas. The flow rate of PH3 gas was 10-4 with respect to the StH, t gas flow rate in the barrier layer, IQ-7 in the μC-8i layer of the photoconductive layer, and 6-8 in the a-5i layer.

When a voltage of 16 kV was applied to the photoreceptor drum with the film formed in this way by corona discharge, the surface potential decreased to 13 kV.
The charge retention rate after 15 seconds at 50V was 55% higher. Furthermore, when this photosensitive drum was attached to a copying machine and an image was formed using positively charged toner, an extremely clear image with high resolution and contrast and no fogging could be obtained.

Example 4 This example differs from Example 1 in that a charge retention layer was formed between the barrier layer and the photoconductive layer. The film formation conditions for this charge retention layer are as follows for a 5iHa gas flow:
B2 Ha gas is 10-5, CH4 gas and N2 gas are 80% in total, reaction pressure is 0.3 torr, high frequency power is 15
It is 0 watts. When the film was formed under these conditions for 3 hours, 7
A μm charge storage layer was fjP deposited. When a voltage of 6.5 kV was applied to the photoreceptor thus formed, a surface potential of 700 μ was obtained.

The charge retention rate after 15 seconds was 68%. When this photoreceptor was attached to a copying machine and an image was produced, an extremely good image was obtained.

29 Example 5 This example differs from Example 1 in that a charge retention layer was provided between the photoconductive layer and the surface layer.

The film formation conditions for this charge retention layer were as follows: PH3 gas was flowed at 10-6%, CHa gas and N2 gas were flowed at 40% of the SiH4 gas flow rate, reaction pressure was 0.4 Torr, and high frequency power was 180 Watts. be.

After 2 hours of film formation, a charge retention layer of 5 μm was formed.

When a voltage of 6 kV was applied to this photoreceptor drum,
A surface potential of 500 V was obtained, and the charge retention rate after 15 seconds was 70%. Even with this photoreceptor, extremely good images were obtained.

In Examples, a charge retention layer was formed between the barrier layer and the photoconductive layer and between the photoconductive layer and the surface layer, respectively. The film forming conditions are the same as in Examples 4 and 5. When a voltage of 5.5 kV was applied to this photoreceptor drum,
The surface potential was 500V. The charge retention rate after 15 seconds was 75%. With this photoreceptor as well, images with high resolution, high contrast, and no fog were obtained.

Example 7 In this example, a charge retention layer was formed between the barrier layer and the photoconductive layer under the same conditions as in Example 5 in Example 3. When a voltage of -6 kV was applied, the surface potential was -450 V and the charge retention rate after 15 seconds was 60%.

Also, extremely good images are available on i! I was beaten.

Example 8 In this example, a charge retention layer was formed between the surface layer and the photoconductive layer under the same conditions as in Example 4 in Example 3. When a voltage of =6 was applied to this photoreceptor, the surface potential was 1400 V and the charge retention rate after 15 seconds was 60%. In this example as well, extremely clear images were obtained.

Example 9 In this example, in Example 7, a charge retention layer similar to that in Example 8 was provided. When a voltage of -5.5 kV was applied, the surface potential increased to 450 mm, and the charge retention rate after 115 seconds was 65%.

Furthermore, extremely excellent images were obtained.

[Effects of the Invention] According to the present invention, electrophotography has high resistance, excellent charging characteristics, high photosensitivity in the visible light and near-infrared light regions, is easy to manufacture, and has high practicality. A photoreceptor can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an apparatus for manufacturing an electrophotographic photoreceptor according to the present invention, and FIGS. 2 to 9 are cross-sectional views showing electrophotographic photoreceptors according to embodiments of the invention. , 1, 2, 3, 4, cylinder, 5; pressure gauge, 6; valve, 7; piping, 8; mixer, 9; reaction vessel, 10; rotating shaft, 13; electrode, 14; drum base, 15; Heater, 16
: High frequency power supply, 19; Gate valve, 21; Support body, 2
2; barrier layer, 23; second layer, 24; first layer, 25; surface layer, 26, 21° charge retention layer, 31, 32. Photoconductive layer. Applicant's representative Patent attorney Takehiko Suzue Figure 2 Figure 3 Part 4 Figure 6 Procedural amendment 1□ Ql, 3, 26. - Director General of the Japan Patent Office Michibe Uga1, Indication of the case Japanese Patent Application No. 179683/19832, Name of the invention Electrophotographic photoreceptor3, Person making the amendment Patent applicant related to the case (307) Toshiba Corporation ( 1 idiot) 4. Agent 5, voluntary amendment 7. Contents of amendment (1) The scope of the patent claims is corrected as shown in the attached sheet. (2) In the specification, on page 23, line 14, on page 24, lines 7 to 8, and on page 25, line 15, the term ``periodic table'' is replaced with ``periodic law.'' Correct the table. (8) In the specification, on page 22, line 8, the word "penetration" is corrected to "penetration." (4) In the specification, on page 28, line 18, the phrase ``0'' is corrected to ``rio-'''. 2. Claims (1) An electrophotographic photoreceptor having an electrically conductive support and a photoconductive layer formed on the electrically conductive support, wherein the photoconductive layer is made of amorphous silicon. The first layer and the second layer made of microcrystalline silicon are laminated, and the layer thickness of this photoconductive layer is 1 to 80 nm.
It is μm. An electrophotographic photoreceptor, wherein the first layer has a thickness of 5 μm or less. (2) Claim 1 characterized in that a barrier layer is formed between the conductive support and the photoconductive layer, and a surface layer is formed on the photoconductive layer. The electrophotographic photoreceptor described above. (3) The barrier layer includes at least one element selected from the elements belonging to Group Ⅰ or Group V of the periodic table, and carbon;
Claim 2, characterized in that the surface layer contains at least one element selected from nitrogen or oxygen, and the surface layer contains at least one element selected from carbon, nitrogen, and oxygen. The electrophotographic photoreceptor described in .

Claims (3)

[Claims] (1) In an electrophotographic photoreceptor having a conductive support and a photoconductive layer formed on the conductive support, the photoconductive layer includes a first layer made of amorphous silicon and a microcrystalline layer. A second layer made of silicon is laminated, and the layer thickness of this photoconductive layer is 1 to 80 nm.
.mu.m, and the thickness of the first layer is 5 .mu.m or less. (2) Claim 1 characterized in that a barrier layer is formed between the conductive support and the photoconductive layer, and a surface layer is formed on the photoconductive layer. The electrophotographic photoreceptor described above. (3) The barrier layer contains at least one element selected from elements belonging to Group III or Group V of the Periodic Table, and at least one element selected from carbon, nitrogen, or oxygen, and the surface layer 3. The electrophotographic photoreceptor according to claim 2, wherein the electrophotographic photoreceptor contains at least one element selected from carbon, nitrogen, and oxygen.