JPS6239870A - 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 plural a-Si or muC-Si electrostatic charge injection preventing layers, a photoconductive layer composed of an muC-Si layer and a-Si layers, and a surface layer, and incorporating specified elements in these layers. CONSTITUTION:A gas mixture of SiH4, B2H6, CH4, He, H2, etc., in a specified composition is decomposed by the glow discharge method and the electrostatic charge injection preventing layers 22, 23 made of a-Si or muC-Si, the photoconductive layer 31 composed of the a-Si layers 24, the muC-Si layer 25, and the a-Si layers 26, and the a-Si surface layer 27 are formed on the conductive substrate 21. The layer 25 has a crystal diameter of 2-10nm, and a crystallinity of 1-90%. The layer 25 has a layer thickness of 0.5-70mum, and each of the layers 24, 26 has a layer thickness of <=0.5mum. At least one of elements of groups III and V and C, N, and O is incorporated in the layer 31, 22, 23, and at least one of C, N, and O is incorporated in the layer 27.

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, ZnO, Se, 5e-Te, or amorphous silicon, or poly-N-vinylcarbazole have been used. (PVCz) or l-linitrofluorene (
Organic materials such as TNF) are used. However, these conventional photoconductive materials have various problems in photoconductive properties or manufacturing, and these materials can be modified depending on the intended use at the expense of some of the properties of the photoreceptor system. I use them 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,
In the Se or 5e-Te system, the crystallization temperature is 65°
Because of its low C, problems with photoconductive properties may occur due to conductivity during repeated copying, resulting in a short lifespan and low practicality.

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

Additionally, organic photoconductive feeds such as PVCz and TNF are suspected carcinogens and pose a threat to human health.
In addition to these two problems, organic materials also have the disadvantage of poor thermal stability and wear resistance, and a short service life.

On the other hand, amorphous silicon (hereinafter abbreviated as a-81)
has recently attracted attention as a photoconductive conversion feed, and is being actively applied to solar cells, thin film transistors, and image sensors. As part of this application of a-3i, attempts have been made to use a-3i for its photoconductive properties in electrophotographic photoreceptors, and photoreceptors using a-8i are collected as non-polluting feed. It has the advantages of not requiring any treatment, having higher spectral sensitivity in the visible light range than other feeds, and having high surface hardness and excellent abrasion resistance and impact resistance.

This a-3i is being studied as a photoreceptor based on the Carlson method, and in this case, the photoreceptor characteristics are required to have high resistance and photosensitivity. Since it is difficult to satisfy this requirement in the body, 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 8i film, and the electrical and optical characteristics vary greatly due to the difference in the amount of hydrogen. That is, as m of hydrogen that enters the a-8i film increases, the optical bandgap increases and the resistance of a-8i 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
H2) Those having bonding structures such as rL 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, as the amount of hydrogen that enters a-8i decreases, the optical bandgap decreases and its resistance decreases, but the photosensitivity to long wavelength light increases. However, when the hydrogen content is low, there is less hydrogen to combine with and reduce silicon tangling bonds. For this reason, the mobility of the generated gear decreases,
As the lifespan becomes shorter, the photoconductive properties deteriorate,
Used as an electrophotographic photoreceptor, it becomes very expensive.

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
However, since the optimum substrate temperature is different, 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.

"I of the Invention"] This invention was made in view of the above 71f circumstances, and has excellent charging ability, low residual potential, and sensitivity over a wide wavelength range up to the near-infrared region. n;<,! ,j
An object of the present invention is to provide a Den-6-Ichiko photographic photoreceptor that has good adhesion to a plate and excellent environmental resistance.

[Summary of the Invention] An electrophotographic photoreceptor according to the present invention includes a conductive support, a charge injection prevention layer 11 formed on the conductive support, and a charge injection prevention layer formed on the charge injection prevention layer. In the electrophotographic photoreceptor, the photoconductive layer includes a first layer made of microcrystalline silicon, and a second layer made of amorphous silicon formed on both sides of the first layer so as to sandwich the first layer. the first layer has a grain size of about 2
015 to 100 Å, crystallinity 1 to 90%, layer thickness 0
．． 5 to 70 μm, the second layer has a layer thickness of 5 μm or less, and the photoconductive layer contains at least one element selected from elements belonging to Group Ⅰ or Group V of the periodic table, carbon, nitrogen, and oxygen. The charge injection prevention layer contains one type of element, and further includes:
It is formed of a plurality of layers of amorphous silicon or microcrystalline silicon containing at least one element selected from elements belonging to Group Ⅰ or Group V of the periodic table, carbon, nitrogen, and oxygen. Injection prevention 1
The thickness of each layer is 0.01 to 15 μm.

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-8i (abbreviated as C-8i) 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-3i is used instead of the conventional a-8l. That is, whether all or some regions of the photoconductive layer are formed of microcrystalline silicon (μC-8i) or a mixture of microcrystalline silicon and amorphous silicon (a-3i); Also, it is formed from a laminate of microcrystalline silicon and amorphous silicon.
In a functionally separated electrophotographic photoreceptor, μC-8i is used for the charge generation layer.

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-8i shows a crystal diffraction pattern near 2θ or 27 to 28.5° i·1. Also, while polycrystalline silicon has a dark resistance of 106Ω・cm, μC-5i has a dark resistance of 106Ω・cm.
It has a dark resistance of 0.11 Ω·cm or more. This μC-8
i is formed by an aggregation of microcrystals with a grain size of approximately several tens of angstroms or more.

11 (The mixture of Jnee Si and a-8i is μC
-81 crystal regions are mixed in a-3i, μC-
5i and a-3i exist in a similar volume ratio. Further, the laminate of μC-8i and a-8t refers to a layer consisting mostly of a-8i and a layer filled with μC-81.

A photoconductive layer having such μC-8i can be produced by depositing μC-8i on a conductive support using silane gas as a raw material by a high-frequency glow discharge decomposition method, similar to a-3t. I can do it. In this case, the temperature of the support is set higher than when forming a-8i,
If the high frequency power is also set higher than that of the A-8i,
It becomes easier to form μC-8i. Furthermore, by increasing the support temperature and high frequency power, the flow rate of a source gas such as silane gas can be increased, and as a result, the film formation rate can be increased. In addition, the raw material gas SiH
By using a gas obtained by diluting high-order silane gas such as 4 and 5i2Ha with hydrogen, μC-3i can be formed with even 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 and 2°3.4 are filled with SiH4 and B2He, respectively.

It contains raw material gases such as H2 and CH4. 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 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 top end of the rotating shaft 10 with its surface aligned with the rotating shaft 1o. Fixed vertically. Inside the reaction vessel 9, a cylindrical electrode 13 is placed on the bottom 11 with its axial center aligned with the axial center of the rotating shaft 1o.

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 tJ+ gas 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 allow the inside of the reaction vessel 9 to be heated by approximately 0.11-
Evacuate to a pressure below Torr. Next, the required reaction gases from the cylinders 1, 2, 3.4 are mixed at a predetermined mixing ratio and introduced into the reaction vessel 9. In this case, the gas flow rate introduced into the reaction vessel 9 is such that the pressure inside the reaction vessel 9 is 0.
Set it so that it is 1 to 1 Torr. Next, motor 1
8 to rotate the drum base 14, and
The drum base 14 is heated to a constant temperature, and a high frequency current is supplied between the electrode 13 and the drum base 14 by the high frequency power source 16 to form a glow discharge between them. As a result, microcrystalline silicon (μC-8t) is deposited on the drum base 14-. Note that N20. NH3, NO2, N2, CH4.

By using C2Hz, 02 gas, etc., these elements can be contained in μC-8i.

In this way, the electrophotographic photoreceptor according to the present invention has a conventional a
Similar to those using -8i, 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-8i contains 0.1 to 30 at % 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 -8t is the optical energy gap Ec of a-8t (1,65 to 1.70
eV). In other words, the optical energy gap of μC-8L 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. The optical energy gap approaches the 1.1 eV of crystalline silicon.

By the way, the μC-3i layer and the a-81 layer absorb light with a larger energy than this optical energy gap, and transmit light with a smaller energy. For this reason, a-9i
absorbs only visible light energy, but μC-8i, which has a smaller optical energy gap than a-8i, can even absorb near-infrared light, which has a longer wavelength and lower energy than visible light. Therefore, μC-3i has high photosensitivity over a wide wavelength range.

μC-8i, which has such characteristics, is suitable as a photoconductor material for laser printers that use semiconductor lasers as light sources. When this a-8i is used as a photoconductor for laser printers, it The light wavelength is 790nm and a
-8i is longer than the wavelength range in which it is highly sensitive, so the photoreceptor sensitivity is insufficient, which exceeds the capability of the semiconductor laser.
It is necessary to apply two laser intensities to the photoreceptor, which poses a practical 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 lt C-8i, which has such excellent photosensitivity properties, it is preferable to incorporate hydrogen into μC-8i.

Doping hydrogen into the μC-8i layer is performed, for example, by glow discharge decomposition method, by introducing silane-based raw material gases such as SiH4 and Si2H6 and carrier gas such as hydrogen into a reaction vessel and causing glow discharge. or 5iFa and S
A mixed gas of a silicon halide such as iCla and hydrogen gas may be used, or a mixed gas of a silane gas and a 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. In view of photoconductive properties, the photoconductive layer containing μC-8i preferably has a thickness of 1 to 80 μm, and more preferably 5 to 50 μm.

Substantially the entire region 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-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-8t is doped with at least one element selected from nitrogen, N, carbon, and oxygen. Thereby, the dark resistance of μC-8t can be increased and the photoconductive properties can be improved.

These elements precipitate at the grain boundaries of μC-8t 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 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 a barrier layer. The barrier layer may be formed using μC-8i, or it may be formed using a-3i.

In order to make μC-5t and a-8i p-type, doping them with elements belonging to Group Ⅰ of the periodic table, such as boron B1 aluminum A1, gallium Ga, indium In, and thallium T1, etc. In order to make the μC-8i layer n-type, it is preferable to dope it with an element belonging to Group V of the periodic table, such as nitrogen N1 phosphorus P1 arsenic As, antimony Sb1, and bismuth Bi. .

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

Preferably, a surface layer is provided on 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 a surface layer, the photoconductive layer is protected from damage. Furthermore, by forming a surface layer, charging ability is improved,
The surface becomes more charged. Materials forming the surface layer include 513N4, SiO2, 5iC1A120
There are inorganic compounds such as 3, a-8iN;H, a-8iO;Hs-18= and a-8iC;H, and organic materials such as polyvinyl chloride and polyamide.

As for the photoconductive material applied to the electrophotographic photoreceptor, as described above, a barrier layer is formed on the support -I-, a photoconductive layer is formed on this barrier layer, and the photoconductive layer is It is not limited to those in which a surface layer is formed on -1- of the support, a charge transfer layer (CTL) is formed on -1- of the support, and a charge generation layer (CTL) is formed on -1- of the charge transfer layer.
It is also possible to configure the system into a functionally divided form in which CG L) is formed. 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. This charge generation layer is preferably made of microcrystalline silicon μC-8i, either partially or completely, with 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, and therefore, it is necessary that the carriers have a long life, have high mobility, and have high transportability. The charge transport layer can be formed using μC-8i. In order to increase the dark resistance and improve the charging ability, it is preferable to light dope an element belonging to either Group 1 or Group 2 of the periodic table. In addition, 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 of the elements C, N, and O is added.
It is also possible to contain more than one species.

If the charge transport layer is too thin or too thick, it will not function adequately. For this reason, 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, the charge retention function can be enhanced and the 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 is a-8i
It may be formed of .mu.C-8i or .mu.C-8i.

The feature of the invention according to this application is that the photoconductive layer is μC-8i
and a second layer made of a-8i formed on both sides of the first layer so as to sandwich this first layer, and this first layer has a crystal grain size of 20 to 100 Å, The crystallinity is 1 to 90%, the layer thickness is 0.5 to 70 μm, the second layer has a layer thickness of 5 μm or less, and the photoconductive layer belongs to Group Ⅰ or Group of the periodic table. At least one element selected from the group consisting of carbon, nitrogen, and oxygen. In addition, the charge injection prevention layer is a group
a-8i or μC-8i containing at least one element selected from elements belonging to the group A-8i, carbon, nitrogen, and oxygen;
The charge injection prevention layer is characterized by having a layer thickness of 0.01 to 15 μm.

FIG. 2 is a sectional view of an electrophotographic photoreceptor embodying the present invention. In FIG. 2, a first charge injection rainproof layer 22 is formed on 1- of the conductive support 21, and a second charge injection prevention layer 23 is formed on this charge injection rainproof layer 22.
At the time of second charge injection, a photoconductive layer 31 is formed on the layer 11 and 23, and a surface layer 27 is formed on -1- of the photoconductive layer 31. This photoconductive layer 31 has a first layer 25 formed of μC-8i, and a first 21-2 layer 24.26 formed by a-3i so as to sandwich this first layer.

A photoconductive layer 31 or a second layer 24° 26 made of a-8i and a first layer 25 made of μC-3i sandwiched between this second layer.
By being a laminate with a laminate, it has the following advantages in electrophotographic properties. First, since the dark resistance of the a-8i layer is relatively high, the charging ability is 17 times higher than that of a single μC-8i photoconductive layer.

Second, the electrophotographic photoreceptor can be moved from the visible light region to the near-infrared region (
For example, high sensitivity can be achieved over a wide wavelength range up to 790 nm, which is the oscillation wavelength of a semiconductor laser. That is, the optical bandgap of μC-8i is usually 1.4 to 1.65 eV, and the optical bandgap of a-8i is usually 1.6 to 1.8 eV, so visible light is However, long wavelength light with low energy is hardly absorbed by the a-8i layer and is transmitted through it. However, the inner region of the l-1 photoconductive layer 31 or lt C-S
This long wavelength light is absorbed in the μC-8i region, which has a small optical bandgap, and generates carriers. In this way, visible light is absorbed by the a-8i layer, while long wavelength light such as near-infrared light is absorbed by the μC-5i layer.
It is absorbed with high efficiency in the layer. Therefore, the photoreceptor according to the present invention has high spectral sensitivity over a wide wavelength range from visible light to near-infrared light, and is therefore suitable for both PPC (plain paper copying machines) and laser printers. It is possible to use a photoreceptor. In this case, the a-8i second layer 24.
The dark specific resistance of No. 26 is preferably 10109 cm or more, more preferably 1011 to 1013 Ωcm.
The optical band gap is preferably 1,60 eV or more, more preferably 1,65 to 1.
It is 8eV. Further, the crystal diameter of the μC-8i first layer 25 is 20 to 100 Å, preferably 30 to 70 Å, and the crystallinity is 1 to 90%, preferably 30 to 7.
It is 0%. Thirdly, the photoconductive layer 31 is in contact with the second charge injection prevention layer 23 and the surface layer 27, and the photoconductive layer 31 has a Zandwich structure with an A-8i layer disposed on the outside. Therefore, what is actually in contact with these charge injection prevention layer 23 and surface layer 27 is a-3i with an optical band gap of 1°60 eV or more. For this reason, μC
8i 111 layers, the photoconductive layer 31
interface (interface with charge injection prevention layer 23 and surface layer 27)
This suppresses sudden changes in the band gap, and prevents the residual potential from increasing by -1 during repeated use.

pC-8i and a-8l themselves are somewhat n-type, but
Photoconductive layer 31 formed of μC-3i and a-3i
Light doping (1,
0-7 to 10-3), μC-3i and a-8i become type 1 (intrinsic) semiconductors, their dark resistance increases, and the S/N ratio and charging ability improve. In addition, the photoconductive layer 31
In addition, when at least one element selected from C10°N is contained, the dark resistance of the photoconductive layer 31 can be further increased and the charging ability can be improved. In this case, the doping meter for C, O, H is 0.1 to 10 atomic %.
It is preferable that

The thickness of the first layer of μC-81 is 0.5 to 20 μm.
It is. This is because if the photoconductive layer is thin, its volume will be small and fewer carriers will be generated, resulting in poor photoconductivity. If the layer is too thick, light will not penetrate into the photoconductive layer. This is because the carrier does not penetrate sufficiently and does not cut through the carrier or the conductive support, so the carrier accumulates and the residual potential becomes high. For these reasons, μ of the photoconductive layer
The thickness of the first layer formed of C-8l needs to be in the range mentioned above, preferably in the range of 3 to 50 μm. Further, the second layer formed by a-5i has a layer thickness of 5 μm or less. In order to increase the sensitivity of the photoconductive layer to long wavelength light, it is preferable to make the μC-8i layer thicker than the a-8i layer.

The charge injection prevention layers 22 and 23 can be formed of a-3t or μC-3i. This charge injection prevention layer 23
+J=L prevents carriers from being injected from the conductive support into the photoconductive layer during charging, and allows carriers to pass through the support with high efficiency during light irradiation. It is preferable that the charge injection prevention layer 22 contains 10@-3 to 1 atomic percent of an element belonging to Group 25-1 or Group V of the periodic table. In addition, the charge injection prevention layer 23 contains 10-
The content is preferably 7 to 10-3 at%. Furthermore, when the charge injection prevention layer 22, 23 contains at least one element among C, 0, and H in the range of 1 to 20 atomic %, the carrier blocking ability is further improved, resulting in good blocking ability without distortion. is obtained.

The surface layer 27 is formed of a-8i containing at least 1 second element among C, 0, and N.

As a result, the surface of the photoconductive layer is protected, corona ion resistance and environmental resistance are improved, and charging ability is improved.

Next, embodiments of the invention will be described.

Example 1 A drum made of Al as a conductive support was loaded into a reaction vessel, and after the inside of the reaction vessel was evacuated, the drum base was heated to 320°C. Then, each layer was formed under the following conditions. First, the first charge injection prevention layer is made of B2H6 with a flow rate ratio of 5 x 10-A and 15% CH with respect to the 5iHa gas flow rate.
4 gas and 100% He gas, the reaction pressure was 0,
The film was formed for 10 minutes at 4 torr and 150 watts of high frequency power. The second charge injection prevention layer has a flow rate ratio of 5X10-6 of B2H6 and 15% CHa to the SiH4 gas flow rate.
Flowing 100% He gas, the reaction pressure was 0.4
The film was formed for 1 hour and 30 minutes at a high frequency power of 150 watts. Next, a photoconductive layer was formed. a-3i of photoconductive layer
The flow rate ratio of B2 He gas to SiH4 gas was 3X10-6, CH2 gas was 5% of 5iHa gas, and He
Gas is 100% SiH4 gas, reaction pressure is 0.41-
The film was formed for 30 minutes under the condition that the high frequency power was 150 watts. After that, B2HG/SiH4 is 10-6, He/S
The film was formed for 5 hours under the conditions of 100% iH4, 50% He/SiH4, reaction pressure of 0.7 torr, and high frequency power of 500 watts. After forming this μC-3i layer, the light a-8
The conditions for forming the i-layer were changed back to the conditions for forming the i-layer, and the film was formed for 30 minutes. The layer thickness of this photoconductive layer was 21 μm, of which the μC-3i layer had a layer thickness of 158 ml, a crystal grain size of 36 Å, and a crystallinity of 30%. The surface layer contains three times as much C as SiH4 gas.
A film was formed by flowing H4 gas at a reaction pressure of 0.5 torr and a high frequency power of 150 watts for 10 minutes.

On the other hand, for comparison, a photoreceptor was manufactured in which the photoconductive layer was a single layer of a-8i. In this conventional photoreceptor, the film forming conditions for the gas composition of the photoconductive layer were a-3t of this example.
The film forming conditions are the same as those in the region, and the film forming time is 4 hours. The layer thickness of this photoconductive layer (a-8i layer) was 24 μm, and the total layer thickness was 30 μm. First, when a voltage of 6 kV was applied to both photoreceptor drums manufactured in this way by corona discharge, the voltage of 5 kV was applied to both photoreceptor drums.
A surface potential of 00V or higher was obtained. Further, when the sensitivity near 800% m was determined as /l1ll, the photoreceptor of this example had a sensitivity 10 times that of the photoreceptor of the comparative example.

In addition, when these photoreceptors were attached to a laser printer and images were formed, defects such as fogging, smeared type, and memory were observed in the comparative example, but in this example, such defects were eliminated. Excellent images with high contrast and high resolution were obtained.

Example 2 In this example, the second charge injection prevention layer is made of μC-
It was formed with 8t. The film forming conditions are as follows: SiH4 gas flow, B2 H8 gas at 10-8, CH4 gas at 1
0%, He→-H2 gas or 300%, reaction pressure is 0.6
Torr, and high frequency power is 350 watts. This second
The layer thickness of the charge injection prevention layer is 5 μm, and the crystal grain size is 5 μm.
0 Å, and crystallinity was 15%. When a voltage of 6 kV was applied to the photoreceptor drum thus produced by corona discharge, a surface potential of 350 V or more was obtained. In addition, when an image was formed on this photoconductor using a laser printer,
As in Example 1, images with high contrast and high resolution were obtained.

[Effects of the Invention] According to the present invention, electrophotography has high resistance, excellent charging characteristics, tip sensitivity characteristics 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 FIG. 2 is a sectional view showing an 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.
13, electrode, 14; drum base, 15; heater, 16
: High frequency power supply, 19: Gate valve, 21; Support body, 2
2; first charge injection prevention layer; 23: second charge injection prevention layer; 24.26° second layer; 25; first layer; 27; surface layer; 31; photoconductive layer. Applicant's agent Patent attorney Takehiko Suzue] d Figure 1 Figure 2 Director General of the Patent Office Michibe Uga 1. Indication of the case % Application No. 179678/1986 2. Name of the invention Electrophotographic photoreceptor 3. Make amendments. Relationship with the Patent Applicant (307) Toshiba Corporation 56 Contents of voluntary amendment The scope of the patent claims will be amended as shown in the attached sheet. (2) In the specification, on page 7, line 13, on page 7, line 16, and on page 24, line 10, the words ``periodic table'' should be corrected to ``periodic table.'' . 2. Claims (1) An electronic device comprising a conductive support, a charge injection prevention layer formed on the conductive support, and a photoconductive layer formed on the charge injection prevention layer. In the photographic photoreceptor, the photoconductive layer has a first layer made of microcrystalline silicon, and a second layer made of amorphous silicon formed on both sides of the first layer so as to sandwich the first layer. One layer has a crystal grain size of 20 to 100X and a crystallinity of 1 to 90q6. The layer thickness should be 0.5 to 70 μm. The second layer has a layer thickness of 5 μm or less. The photoconductive layer is 1
An element belonging to Group Ⅰ or Group V of the periodic table. The charge injection prevention layer contains at least one element selected from carbon, nitrogen, and oxygen. Carbon, an element belonging to Group Ⅰ or Group V of Encyclopedia 11. The charge injection prevention layer is formed of a plurality of layers of amorphous silicon or microcrystalline silicon containing at least one element selected from nitrogen and oxygen, and the thickness of the charge injection prevention layer is 0.01 to 15 μm. Characteristic electrophotographic photoreceptor. (2) An electrophotographic photosensitive material according to claim 1, characterized in that a surface layer containing at least one element selected from carbon, nitrogen, and oxygen is formed on the photoconductive layer. body.

Claims (2)

[Claims] (1) An electrophotographic photoreceptor comprising a conductive support, a charge injection prevention layer formed on the conductive support, and a photoconductive layer formed on the charge injection prevention layer, The photoconductive layer has a first layer made of microcrystalline silicon, and a second layer made of amorphous silicon formed on both sides of the first layer so as to sandwich the first layer, and the first layer has crystal grains. The photoconductive layer has a diameter of 20 to 100 Å, a crystallinity of 1 to 90%, a layer thickness of 0.5 to 70 μm, a layer thickness of the second layer is 5 μm or less, and the photoconductive layer has a crystallinity of 1 to 90%. The charge injection prevention layer contains at least one element selected from elements belonging to Group III or Group V, carbon, nitrogen, and oxygen, and further contains an element belonging to Group III or Group V of the periodic table. The charge injection prevention layer has a thickness of 0.01 to 15μ.
An electrophotographic photoreceptor characterized in that m. (2) An electrophotographic photosensitive material according to claim 1, characterized in that a surface layer containing at least one element selected from carbon, nitrogen, and oxygen is formed on the photoconductive layer. body.