JPS6258266A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the titled body having an excellent electrostatic charge capacity, a low residual potential, a high sensitivity at a broad wavelength range of an up to near infra-red ray, a good sticking property to a substrate and an excellent resisting property to an environment by specifying forming materials of an electrostatic charge generating layer and an electrostatic charge transfer layer, and a thickness of said layers of a laminated body respectively. CONSTITUTION:The electrostatic charge generating layer 31 is composed of the laminated body of the 1st layer 24 made of an a-Si and the 2nd layer 23 made of the n-type muc-Si. The electrostatic charge transfer layer 22 is composed of a muc-Si. The 1st layer 24 and the 2nd layer 23 contain a hydrogen atom. The thickness of the 1st layer 24 is 0.1-5mum that of the 2nd layer 23 is 1-10mum. The electrostatic charge transfer layer 22 contains at least one of elements selected from C, O and N elements and a hydrogen atom, and the thickness of said layer is 3-80mum.

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 materials for forming the photoconductive layer of an electrophotographic photoreceptor, inorganic materials such as CdS, ZnO1Se, 5e-Te, or amorphous silicon, or poly-N-vinylcarbazole (PVCz) have been used. ) or trinitrofluorene (TNF)
Organic materials such as However, these conventional photoconductive materials have various problems in terms of photoconductive properties and manufacturing, and it is necessary to use these materials depending on the purpose of use, sacrificing some of the characteristics of the photoreceptor system. There is.

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, the se needs to be recovered, which adds to the recovery cost. Also,
In the Se or 5e-Te system, the crystallization temperature is 65°C
Therefore, during repeated copying, problems with the photoconductive properties arise due to residual snow, etc., and therefore, the service life is short and practicality is low.

Furthermore, ZnO is susceptible to oxidation-reduction and is significantly affected by the environmental atmosphere, resulting in a problem of 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. The drawback is that it has a short lifespan.

On the other hand, amorphous silicon (hereinafter abbreviated as a-3i)
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 this application of a-8i, attempts have been made to use a-3i as a photoconductive material for electrophotographic photoreceptors, and photoreceptors using a-8i are recycled as 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-3i 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 3i 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 that enters the a-3i 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 a-8ill is high, depending on the film formation conditions, (S
Those having a bonding structure such as iH2)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-8i reduces the optical bandgap and reduces its resistance, but increases its sensitivity to long wavelength light. However, when the hydrogen content is low, there is less hydrogen to combine with and reduce silicon dangling bonds. Therefore, the mobility of the generated carriers decreases,
As the lifespan becomes shorter, the photoconductive properties deteriorate,
This makes it difficult to use as an electrophotographic photoreceptor.

In addition, as a technique to increase the sensitivity to long wavelength light, there is a method of mixing silane-based gas and germane GeH+ and generating a film with a narrow optical band gap by glow discharge decomposition, but in general, silane-based gas and GeH+
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, a charge transport layer formed on the electrically conductive support, and a charge generation layer formed on the charge transport layer. In the electrophotographic photoreceptor, the charge generation layer includes a first layer formed of amorphous silicon containing hydrogen and having a layer thickness of 0.1 to 5 μm, and a first layer containing hydrogen and having a layer thickness of 1 to 10 μm. and a second layer formed of n-type microcrystalline silicon, and the charge transport layer contains hydrogen and at least one element selected from carbon, oxygen, and nitrogen, and has a layer thickness of 3 to 3. It is characterized by being made of 80 μm microcrystalline silicon.

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 a photoreceptor (abbreviated as c-8i) for at least a portion of an electrophotographic photoreceptor.

[Embodiments of the Invention] The present invention will be described in detail below. The feature of this invention is that μc-8i is used instead of the conventional a-3i. In other words, whether all or some regions of the photoconductive layer are formed of microcrystalline silicon (μc-31) or a mixture of microcrystalline silicon and amorphous silicon (a-8+); Alternatively, it is formed of a laminate of microcrystalline silicon and amorphous silicon. Also,
In a functionally separated type electrophotographic photoreceptor, μc-8i is used for the charge generation layer.

μC-8i is a-
8i 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-8i shows a crystal diffraction pattern in which 2θ is around 27 to 28.5°. In addition, while polycrystalline silicon has a dark resistance of 108Ω・1, μc-3i has a dark resistance of 1011Ω.
- Has a dark resistance of 1 or more. This μc-3i is formed by an aggregation of microcrystals having a grain size of approximately several tens of angstroms or more.

A mixture of μc-8i and a-3i means that the crystalline region of μc-8i is mixed in a-8i, and μc-8i and a
-8i exists in a similar volume ratio. Also,
The laminate of μc-8i and a-8i is mostly a-3
A layer consisting of i and a layer filled with μc-8i are laminated.

Similar to a-8i, a photoconductive layer having μc-8t can be produced by depositing μc-8t 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-8i and the high frequency power is also set higher than when forming a-3i, μc
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 the raw material gas SiH* and high-order silane gas such as Si2H6 with hydrogen,
μc-sr can be formed with higher efficiency.

FIG. 1 is a diagram showing an apparatus for manufacturing an electrophotographic photoreceptor according to the present invention. For example, the gas cylinders 1.2° and 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. You can do it. 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, so that a high frequency current is supplied between the electrode 13 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
．． From 2.3.4, the required reaction gases 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
is activated 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 a high frequency current between the electrode 13 and the drum base 14 to create a glow between them. form a discharge.

As a result, microcrystalline silicon (μc-3i) is deposited on the drum base 14. Note that N20. NHs, NO2, N2, CH4.

These elements can be contained in μc-3i by using 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 -3i, 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 GeH4 is not required, there is no need to provide waste gas treatment equipment, and industrial productivity is extremely high.

It is preferable that μc-3i contain 0.1 to 30 at % of hydrogen H. As a result, the dark resistance and bright resistance become harmonious, and the photoconductive properties are improved. μc
The optical energy gap Ea of -3i is the optical energy gap Ea of a-3i (1,65 to 1.70e
V) is small compared to V). In other words, the optical energy gap of μc-8i changes depending on the crystal grain size and crystallinity of the μc-3i microcrystal, and as the crystal grain size and crystallinity increase, the optical energy gap decreases. Magnetization′°
The optical energy gap of silicon approaches 1.1e■. By the way, the μc-8i layer and the a-3i layer absorb light with a larger energy than this optical energy gap, and transmit light with a smaller energy. For this reason, a-8i
absorbs only visible light energy, but μc-3i, which has a smaller optical energy gap than a-8t, can even absorb near-infrared light, which has a longer wavelength and lower energy than visible light. Therefore, μc-8i has high photosensitivity over a wide wavelength range.

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 3i is longer than the wavelength region in which the sensitivity is high, 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, which poses a practical problem. On the other hand, when the photoreceptor is formed using 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, μc-8t
-8i preferably contains hydrogen.

For doping μc-8ill with hydrogen, for example, when using a glow discharge decomposition method, a silane-based raw material gas such as 5ill and 5i2Hs and a carrier gas such as hydrogen are introduced into a reaction vessel and glow discharge is performed. , S i F4
A mixed gas of silicon halide such as and 5iC1+ and hydrogen gas may be used, or a silane-based gas and
The reaction may be performed using a mixed gas with silicon halide. Furthermore, the μc-8i layer can be formed not only by glow discharge decomposition but also by physical methods such as sputtering. Note that the photoconductive layer containing μc-8i preferably has a thickness of 1 to 80 μm, and more preferably 5 to 50 μm, in view of photoconductive properties.

Substantially the entire region of the photoconductive layer may be formed of .mu.c-8i, or may be formed of a mixture or a laminate of a-8t and .mu.c-8i. 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-8i 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 believed that the density of states existing in the forbidden cloth 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 suppresses the flow of charge between the conductive support and the photoconductive layer, thereby increasing the charge retention function on the surface of the photoconductive member and increasing the charging ability of the photoconductive member. .

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 as the barrier 11i. Barrier layer is μc-8i
It is also possible to form the barrier layer using a-8i.

In order to make μc-31 and a-3i p-type, it is preferable to dope them with elements belonging to Group 1 of the periodic table, such as boron B1 aluminum AI, gallium Qa, indium In, and thallium T1. , μc-8i
In order to make the layer n-type, elements belonging to Group Ⅰ of the periodic table, such as nitrogen N1 phosphorus P1 arsenic As, antimony S
It is preferable to dope with B, bismuth 81, or the like.

This n-type impurity or doping with n-type impurities prevents charges from moving from the support side to the photoconductive layer.

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

Since μc-3i 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 the surface layer, the photoconductive layer is protected from damage. Furthermore, by forming a surface layer, charging ability is improved,
The surface becomes more charged. The materials forming the surface layer include 5iaN+, SiO2, and SiC.

Al2O:l, a-8iN:H, a-8iO;H.

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

As described above, electrophotographic photoreceptors are limited to those in which a barrier layer is formed on a support, a photoconductive layer is formed on this barrier layer, and a surface layer is formed on this photoconductive layer. First, a charge transfer layer (CTL') may be formed on the support, and a charge generation layer (CGL) may be formed on the charge transfer layer. A barrier layer may be provided between the transfer layer and the support. The charge generation layer generates carriers by irradiation with light. Part or all of the layer is made of microcrystalline silicon μC. -3i, and its thickness is 1 to 10 μm.
It is preferable to The charge transfer layer is a layer that allows carriers generated in the charge generation layer to reach the support side with high efficiency, and therefore, the carriers need to have a long life, high mobility, and high transportability. The charge transport layer can be formed of a-8i. In order to increase dark resistance and improve chargeability, it is preferable to light-dope with an element belonging 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 O 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. Note that 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-3i or μc-8i.

The feature of the invention according to this application is that the charge generation layer is a-8i
The first layer is made of .mu.c-3i, and the second layer is made of n-type .mu.c-3i.The charge transport layer is made of .mu.c-8i. 2 to 4 are cross-sectional views of an electrophotographic photoreceptor embodying the present invention, and FIG.
In the figure, a charge transport layer 2 is placed on a conductive support 21.
2 is formed, and a charge generation layer 31 is formed on the charge transport layer 22. This charge generation layer 31 is similar to the charge transport layer 2
A 21t23 formed of μc-8i on top of the second layer 2, and a first layer 24 formed of a-8i on this second layer. On the other hand, in FIG. 3, the first layer 24 and the second layer 23 of the charge generation layer 32 are formed opposite to the charge generation layer 31, and the first layer 24 formed of a-3i transports charges. layer 2
a second layer 23 made of μc-8i;
is formed on the first layer 24. Furthermore, the photoreceptor shown in FIG. 4 is characterized in that a barrier layer 25 is formed between the charge transport layer 22 and the conductive support 21, and a surface 1i26 is formed on the charge generation layer 31. This is different from the photoreceptor shown in FIG. In this invention, the first layer 24 and the second layer 23 are
, the first layer has a thickness of 0.1 to 5 μm, the second layer has a thickness of 1 to 10 μm, and the charge transport layer 22 is made of at least one selected from C, O, and N. It is characterized by containing the elements and H, and having a layer thickness of 3 to 80 μm.

Since the charge generation layers 31 and 32 are a laminate of the first layer 24 made of A-8i and the second layer 23 made of μC-3i, the photoreceptor can be heated from the visible light region to the near-infrared region. (For example, high sensitivity can be achieved up to around 790 nm, which is the oscillation wavelength of a semiconductor laser). In other words, μc-3i is
Since its optical energy gap Ea is smaller than the optical energy gap 1.65 to 1.70 eV of a-8i, it also absorbs long wavelength light with low energy such as near-infrared light and generates charges. have For this reason, μC-
The second layer 23 formed of 8i has an oscillation wavelength of 790 nm.
It has high spectral sensitivity to long wavelength light such as semiconductor laser light. On the other hand, a-8i has high spectral sensitivity to visible light.

Therefore, by using μC-8i and a-3i in the charge generation layer, this photoreceptor can be used in both PPC (plain paper copying machines) and laser printers using semiconductor lasers.

μc-3i itself is somewhat n-type, but this μc-8
By adding an element belonging to Group V of the periodic table to i, μC-
Actively convert 8i to n-type. Thereby, the sensitivity of the μc-8i second layer to long wavelength light can be further increased. The doping amount of this group V element is 10-8 to 10
"3 atomic %, preferably 10-B to 104 atomic %. If there is too much doping, μc-8i becomes a strong n-type, and the specific resistance in the dark (dark specific resistance) becomes low. This is because if the doping amount is too small, the sensitivity to long wavelength light will be insufficient.

Although the specific resistance of μc-8t is relatively low, this is compensated for by the first layer 24 formed of a-8i. In other words, a-3i has a relatively high specific resistance, and by disposing a-8i, charging ability can be increased.

The first layer 24 formed with this a-8i is
Lightly doped with elements belonging to the group (10-T to 10-3
%), the first layer 24 is type 1 (intrinsic)
It becomes a semiconductor, has a higher dark specific resistance, and improves the S/N ratio and charging ability. Furthermore, the dark specific resistance can be increased by containing at least one element among C, O, and N in the charge generation layers 31 and 32 (the first layer 24 and the second layer 23) to an extent that does not reduce the photoconductivity. The charging capacity (charge retention function) can be further enhanced. The content of C, O, and N is
The content is preferably 0.1 to 10 at%.

The layer thickness of the first layer 24 and the second layer 23 is 0.1 to 5.
μm and 1 to 10 μm. This is because if the charge generation layer is too thick, it will take a long time to form the film and the layer will easily peel off, while if the charge generation layer is too thin, the carrier generation efficiency will be low. . In addition, the first layer 2
4 is the one located above (light incidence side) than the second layer 23 (second layer 23).
Fig. 3) is preferable to the opposite case (Fig. 3). This is because μC-8i also absorbs visible light, so μC-8i second
If m is above, visible light will be absorbed by the μc-3i second layer before reaching the lower a-8i first layer, so
This is because the charge generation efficiency is low.

The charge transport layer 22 is a layer provided to transport carriers generated in the charge generation layers 31 and 32 to the support 21 with high efficiency, and is formed of μc-8i, which has good carrier running properties. . By lightly doping this charge transport layer 22 with an element belonging to Group 1 of the periodic table, its dark resistance can be increased and the charge retention function can be indirectly improved.

Further, the charge transport layer 22 contains a small amount (all one kind of element) selected from C, O, and N. This is μc-3
This is because since i has a relatively low resistance, it is necessary to increase the resistance by incorporating C90°N. Further, it is ideal that the charge transport layer does not have traps (density of states) that trap carriers. Therefore, in order to remove silicon dangling bonds that become traps, a trace amount of C is
The charge transport layer 22 is made to contain 90°N. This C,O.

Considering carrier mobility, the amount of N is 20 atomic%.
It is preferable that it is below. Further, it is preferable that H in the charge transport layer 22 be 1 to 10 atomic %. The layer thickness of the charge transport layer is 3 to 80 μm. In order to maintain a high chargeability of the charge transport layer, it is necessary to increase the layer thickness, but if the charge transport layer is too thick, it becomes difficult for carriers to travel and it is difficult for the carriers to reach the support. This is because it becomes difficult.

In the photoreceptor shown in FIG. 4, a barrier layer 25 and a surface layer 26 are formed. Barrier layer 22 can be formed of μc-8i or a-8i.

μc-8i has high carrier mobility and good runnability, but has a relatively slow film formation rate and is somewhat difficult to manufacture. On the other hand, a-31 has relatively low running performance, but is easy to manufacture. In addition, μc-9i or a-8 constituting the barrier layer
The barrier layer 22 can be made into a p-type or n-type semiconductor by doping an element belonging to group Ⅰ or group V of the periodic table into i. Its content is 104 to 1
Preferably, it is 0 atomic %. When the surface of the photoreceptor is positively charged, the barrier layer is made p-type in order to prevent injection of electrons from the support 21 side. On the other hand, when the photoreceptor is used with a negative charge, a-8i or μc-3i is doped with P or the like to make the barrier layer 25 n-type. Furthermore, it is also possible to form a barrier layer by expanding the band gap.

In this case, it is preferable that the barrier 1125 contains at least one element among C, O, and N in a range of 1 to 20 atomic %. Thereby, injection of carriers from the support 21 side to the charge transport layer 22 can be effectively prevented, and the charge retention ability is significantly improved. The thickness of the barrier layer 25 is preferably 0.1 to 10 μm.

As shown in FIG. 4, a surface layer 2 is placed on the charge generation layer 31.
In the electrophotographic photoreceptor formed with 6, this surface layer 2
6, a-3i (a-8iC; Hla-8iO; H, a-8iN:H,
a-8iCN; H, etc.). This protects the surface of the photoconductive layer and improves environmental resistance and charging ability. The content of C, O, and N is preferably 1 to 50 atomic percent, and the layer thickness is 0.01 to 1 atomic percent.
Preferably, it is 0 μm.

Next, embodiments of the invention will be described.

After loading the TODRAM made of AI as a conductive substrate into the reaction vessel, the inside of the reaction vessel is evacuated by a diffusion pump (not shown) to create a vacuum of about 0.1 torr or less. After that, the drum base was heated and kept at about 400℃, and the drum base was heated to 2008CCM.
SiH+ gas with a flow rate of , B2 H6 gas with a flow rate ratio of 10"3 to this Si H4 gas flow rate, and 100S
CCM CH4 gas was mixed and supplied to the reaction vessel. Thereafter, the inside of the reaction vessel was evacuated using a mechanical booster pump and a rotary pump, and the pressure was adjusted to 1 Torr. While rotating the drum base, 13.56MH2 was applied to the electrode.
SiH+ was applied between the electrode and the drum base by applying a high frequency power of 300 watts.

Generate plasma of B2 +-16 and CH4, 15
After continuing film formation for a minute, the supply of gas and the application of electric power were stopped. As a result, a barrier layer having a layer thickness of 2.1 μm was formed. After that, 5008CCM of SiH+ gas,
Supplying 15008 CCM of H2 gas into the reaction vessel,
Furthermore, CH4 gas, 02 gas or N2 gas is added to 11005
Only CC was supplied into the reaction vessel. And the reaction pressure is 0
．． A charge transport layer of 20 μm was formed by forming a film for 4 hours under conditions of 8 torr and high frequency power of 1 kW.

Next, a charge generation layer was formed. First, the flow rate of SiH4 gas was 5008CCM, the flow rate ratio of PH9 gas to SiH+ gas was 10', and the flow rate of H2 gas was 110008CCM.
These gases were introduced into the reaction vessel by setting CC.

Then, a film was formed by applying 500 watts of power for 1 hour at a reaction pressure of 0.7 torr, and a 5 μm μc-8i second film was formed.
formed a layer. Next, 5008CCM of SiH+ gas and 82CCM of 2X10-8 flow rate ratio to SiH+ gas
The film was formed for 30 minutes under the conditions of supplying 86 gas, reaction pressure of 0.5 torr, and high frequency power of 500 watts, resulting in a layer thickness of 3
．． A 5 μm a-8i first layer was formed. After that, S i
H4 gas at 300SCCM, CH4 gas at 1508C
CM, reaction pressure is 1 torr, power is 200 watts, 1
The film was formed for 5 minutes to form a surface layer of 1 μm.

In the electrophotographic photoreceptor film formed in this way, C
Regardless of whether H4 gas, 02 gas or N2 gas is used, the average particle size of the charge transport layer is 30.
The average particle size of the second charge generation layer was 40 particles. The electrostatic characteristics of this electrophotographic photoreceptor are that the initial potential is 450V.
, the charge retention rate after 15 seconds is 75%, and the half-life exposure amount for 790 nm laser light is 9. Oerg/cd, and extremely good electrostatic properties were obtained. Furthermore, when the reproducibility and stability of the transfer process were investigated by repeated copying, it was demonstrated that the transferred images were extremely good (1) and were excellent in corona resistance, moisture resistance, abrasion resistance, etc.

In this example, the film forming conditions for the μc-8i second layer were such that the PH3 gas flow rate was increased so that the ratio of PH3 gas/S t H4 gas was 2×104. Other conditions are the same as in Example 1. In this example as well, the initial potential is 3
50V, charge retention rate after 15 seconds is 70%, half-decreased exposure amount with 790nm laser light is 8.2era/cd,
Although the initial potential was slightly lower than in Example 1, the half-mounting light amount showed a good value.

[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 4 are cross-sectional views showing the electrophotographic photoreceptor according to an embodiment of the invention. 1.2, 3, 4: cylinder, 5; pressure gauge, 6; valve, 7
; Piping, 8: Mixer, 9; Reaction container, 10: Rotating shaft, 1
3: Electrode, 14 Nidrum base, 15; Heater, 16: High frequency power supply, 19: Gate valve, 21: Support, 22:
Charge transport layer, 23; 211.24; first layer, 25; obstruction L26: surface layer, 31, 32; charge generation layer.

Claims (4)

[Claims] (1) In an electrophotographic photoreceptor having a conductive support, a charge transport layer formed on the conductive support, and a charge generation layer formed on the charge transport layer, the charge The generation layer includes a first layer made of amorphous silicon containing hydrogen and having a layer thickness of 0.1 to 5 μm, and a second layer made of n-type microcrystalline silicon containing hydrogen and having a layer thickness of 1 to 10 μm. The charge transport layer is formed of microcrystalline silicon containing hydrogen and at least one element selected from carbon, oxygen, and nitrogen and having a layer thickness of 3 to 80 μm. Characteristic electrophotographic photoreceptor. (2) The charge transport layer belongs to Group III or V of the periodic table.
The electrophotographic photoreceptor according to claim 1, characterized in that the electrophotographic photoreceptor contains an element belonging to the group A. (3) The charge generation layer belongs to Group III or V of the periodic table.
The electrophotographic photoreceptor according to claim 1 or 2, characterized in that the electrophotographic photoreceptor contains an element belonging to the group A. (4) The charge generation layer contains at least one element selected from carbon, oxygen, and nitrogen. Electrophotographic photoreceptor.