JPS62115455A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having superior photoconductive characteristics and environmental resistance by using N-type a-Si as at least part of an electrophotographic sensitive body. CONSTITUTION:A charge generating layer 23 is formed on an electrically conductive support 21 with a charge transferring layer 22 in-between. The charge generating layer 23 is made of N-type amorphous silicon contg. H and has 1-10mum thickness. The charge transferring layer 22 is made of microcrystalline silicon contg. H and at least one among C, O and N and has 3-80mum thickness. Thus, an electrophotographic sensitive body having high resistivity, superior electrostatic charge characteristics, high sensitivity in the visible light and near infrared light regions and high practicality can easily be produced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention provides improved charging characteristics, photosensitivity characteristics, and durability! The present invention relates to an electrophotographic photoreceptor having excellent one-boundary properties.

[Prior art and its problems] Conventionally, the light guide Nli! As a material for forming i, an inorganic material such as CdS, ZnO, Se, 5e-Te, or amorphous silicon, or an organic material such as poly-N-vinylcarbazole (PVCz) or trinitrofluorene (TNF) W is used. 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 process is 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°C
Therefore, during repeated copying, problems with the photoconductive properties may occur due to remaining snow, etc., and therefore, the service life is short, making it impractical.

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. , has the disadvantage of 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-3i, attempts have been made to use a-5i as a photoconductive material for electrophotographic photoreceptors, and photoreceptors using a-3i are collected 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 abrasion 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 this requirement with a photoreceptor, a layered structure is used in which a barrier layer is provided between the photoconductive layer and the conductive support, and a surface 'R charge retaining layer is provided on the photoconductive layer. This satisfies these requirements.

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 8ill, and the electrical and optical characteristics vary greatly due to the difference in the amount of hydrogen. That is, a-3i1
When the amount of hydrogen that enters into 1 increases, the optical bandgap increases and the resistance of a-3i increases, but this also reduces the photosensitivity to long wavelength light. Difficult to use with mounted laser beam printer. Also, a-8i
When the hydrogen content in III is high, depending on the film forming conditions, those having bonding structures such as (SiH2)n and SiH2 may occupy most of the area in the film. In this case, voids increase and silicon dangling bonds increase, resulting in deterioration of photoconductive properties and rendering the material unusable as an electrophotographic photoreceptor. Conversely, when the amount of hydrogen penetrating into a-8i decreases, the optical bandgap becomes smaller 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 dangling bonds. For this reason, the mobility of the generated carriers is reduced, the life span is shortened, and the photoconductive properties are deteriorated, making it difficult to use as an electrophotographic photoreceptor.

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.

Also, since GeH+ waste gas becomes toxic gas when oxidized, is there any way to treat the waste gas? ! It's rough. Therefore, such technology is not practical.

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

[Means for Solving the Problems] The electrophotographic photoreceptor according to the present invention includes a conductive support, a charge generation layer, and a charge transport layer disposed between the conductive support and the charge generation layer. In an electrophotographic photoreceptor having the following,
The charge generation layer is made of n-type amorphous silicon containing hydrogen and has a layer thickness of 1 to 10 μV, and the charge transport layer is made of hydrogen and at least one element selected from carbon, oxygen, and nitrogen. It is characterized by being formed of microcrystalline silicon containing and having a layer thickness of 3 to 80 μm.

This 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, the present invention was completed based on the idea that this object could be achieved by using n-type a-3i for at least a portion of an electrophotographic photoreceptor.

This invention will be explained in detail below. The feature of this invention is that a 6-type A-8i is used instead of the conventional A-3i. In other words, at least a part of the charge generation layer is formed of n-type a-3i, or is formed of n-type a-3i.
-8i and an intrinsic semiconductor (i type) a-8i stack, n
Type a-8i and microcrystalline silicon (hereinafter referred to as
(abbreviated as μC-8i), or a laminate of n-type a-3i and a-8i containing at least one element selected from carbon C, a-element O, nitrogen, and N. There is. Further, in an electrophotographic photoreceptor having a photoconductive layer, n-type a-8i is used for the photoconductive layer.

The charge generation layer generates carriers upon irradiation with light. This charge generation layer is made of n-type a-8: containing hydrogen H, and has a thickness of 1 to 10 μm. The charge transport layer is a layer that allows carriers generated in the charge generation layer to reach the support side with an efficiency of 8. Therefore, it is necessary that the carriers have a long life, have high mobility, and have high transportability.

The charge transport layer includes at least one selected from C1O and N.
It is formed of μC-8i containing seed elements and hydrogen. If the charge transport layer is too thin or too thick, it will not perform its function satisfactorily. Therefore, the thickness of the charge transport layer is preferably 3 to 80 μm.

Preferably, a barrier layer is provided between the conductive support and the charge transport layer. This barrier layer suppresses the flow of charge between the conductive support and the photoconductive layer, thereby enhancing the charge retention function on the surface of the photoreceptor and increasing the charging ability of the photoreceptor. In the Carlson method, when the surface of the photoreceptor is positively charged, the barrier layer is made p-type in order to prevent electrons from being injected from the support side to the charge transport layer.

On the other hand, when the surface of the photoreceptor is negatively charged, the barrier layer is made n-type in order to prevent holes from being injected from the support side to the charge transport layer. It is also possible to form an insulating film on the support as a barrier layer. The barrier layer may be formed using μc-3i, or may be formed using a-3i.

N-type a-3i is formed by doping a-8i with an element belonging to Group V of the periodic table, such as nitrogen N, phosphorus P1 arsenic As, antimony sb, and bismuth 3i. The n-type a-8i may be either an n-type lightly doped with these doping elements or an n+ type heavily doped, but it can be used with various types of light when used as an electrophotographic photoreceptor. Considering the conductive properties, these doping elements should be added in an amount of 10 to 10
It is preferable to use n-type a-3i containing 3 atomic %.

μc-8i is a-
3i 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-3i 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・α, μc-8i has a dark resistance of 1Q11Ω.
- Has a dark resistance of 0111 or more. This μC-3i is formed by an aggregation of microcrystals having a grain size of approximately several tens of angstroms or more.

By using n-type a-81 in the charge generation layer as in the present invention, an electrophotographic photoreceptor is highly sensitive to long wavelength light, especially to semiconductor laser light having an oscillation wavelength around 790 nm. can be obtained. Therefore, the electrophotographic photoreceptor according to the present invention can be applied not only to an RPC (plain paper copying machine) but also to a laser printer equipped with a semiconductor laser. In Figure 1, the horizontal axis shows the P doping ratio expressed as PHi'/S 12Hs gas flow rate ratio, and the vertical axis shows the conductivity of n-type a-8i (1/Ω・c
II) is a graph showing the influence of doping ratio on conductivity. When the flow rate ratio PH3/S i Hs of PH3 gas in this film forming gas increases, the n-type a-8
The content of P element in i becomes high, and it becomes ln type (n+). As shown in Figure 1, when P is not included, the dark conductivity σD is 3.87X10-11 (1/Ω・
OR), and the conductivity when irradiated with 790nm laser light (7P (790nIn> is 1.15x10-'
(1/Ω·cm). However, increasing the doping ratio increases the conductivity and PH3/S 12H
When the s doping ratio is 33 ppm, ap (79
0 nm) becomes 5.57×10 −8 (1/Ω·bacterial), which is an increase of more than one digit compared to the case where P is not doped. In addition, in this case, σD is also 5.28X10-9
(1/Ω・C scrap), and as the doping ratio increases, both ap (790n1l) and σD increase, but in the end, at the node where the doping ratio is 10-6 to 10-5, ap (790n1ll) becomes a high value that is more than one order of magnitude higher than that without P doping, and the S/N ratio can be increased to about three orders of magnitude. Therefore, by using n-type a-8i doped with P or the like at this level of doping ratio in the charge generation layer, it is possible to obtain a photoreceptor with sufficiently high sensitivity to long wavelength light, which is suitable for laser printers. It can be fully put to practical use as a photoreceptor.

Next, by making a-8i n-type in this way,
The reason why sensitivity to long wavelength light can be increased will be explained. FIG. 2 is a graph showing the relationship between the PH3/S i H6 doping ratio on the horizontal axis and the optical band gap and activation energy on the vertical axis. As is clear from FIG. 2, the optical bandgap does not change even if the doping ratio is changed and remains substantially constant. On the other hand, the activation energy ΔE becomes smaller as the doping ratio is increased. In this case, the optical bandgap Ea is the energy difference between the #J1 child band and the conduction band, and the activation energy ΔE is the energy difference between the Fermi levels F, L and the conduction band. . The optical band gap Ea is the energy required to excite electrons from the valence band to the conduction band, and the smaller the optical band gap Ea, the lower energy light can be absorbed to generate carriers. On the other hand, the Fermi level FL exists between the conduction band and the valence band, and the smaller the activation energy, the more easily carriers are excited. Therefore, the smaller the activation energy, the
High sensitivity to long wavelength light with small hv (blank constant x frequency) is achieved, and carriers are excited. By using n-type a-8i in the charge generation layer as in this invention, the sensitivity to long wavelength light increases as shown in Figure 1. By doping a-8i to make it n-type, the Fermi level F
This is considered to be because -L has increased, and as a result, the activation energy ΔE has become smaller, and the sensitivity to light with low energy (long wavelength light) has increased.

Such a charge generation layer having n-type a-3i is formed by using silane gas as a raw material and phosphine gas (PH3 gas) as a dopant gas using a frequency glow discharge decomposition method to form a conductive support layer. It can be manufactured by depositing n-type a-8i on the body. In this case, the hydrogen content in the layer can be controlled by diluting high-order silane gas such as SiH4 and 5i2es, which are raw material gases, with hydrogen or by mixing hydrogen gas with a silane gas. Furthermore, by using a diluent gas, it is possible to increase the deposition rate and form uniform plasma.

FIG. 3 is a diagram showing an apparatus for manufacturing an electrophotographic photoreceptor according to the present invention. For the gas cylinder 1.2°3.4, for example, 3iH4 and Si2H6, respectively.

Raw material gases such as B2 H6, H2, and CH4 are accommodated. The gas in these gas cylinders 1.2.3.4 is supplied to a mixer 8 via a pulp 6 for adjusting stream I and a pipe 7. 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. Reaction container 9
A rotary shaft 10 is attached to the bottom 11 of the rotary shaft 10 so as to be rotatable around the vertical direction, and a disk-shaped support 12 is fixed to the upper end of the rotary shaft 10 with its surface perpendicular to the rotary shaft 10. has been done. Inside the reaction vessel 9, a cylindrical M113 is placed at the bottom 11 with its axial center aligned with the axial center of the rotating shaft 10.
is installed on top. 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. Electrode 13
A high frequency electric current 11116 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, the reaction vessel 9 is connected via a gate valve 18 to a suitable 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 and 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, a-3i is deposited on the drum base 14.

Note that N20. NH3, NO2, N2.

By using CH4, C2H4,02 gas, etc.
These elements can be contained in a-3i.

As described above, the electrophotographic photoreceptor according to the present invention can be manufactured using a closed system manufacturing apparatus, similar to that using the conventional a-3i, and is thus 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 Get-1+ is not required, there is no need to provide waste gas treatment equipment, and industrial productivity is extremely high.

The n-type a-3i, a-3i, or μc-8i contains 0.1 to 30 atom % of hydrogen. As a result, the dark resistance and bright resistance become harmonious, and the photoconductive properties are improved. Doping hydrogen into the n-type a-3i, a-8i or μc-8i layer is performed using, for example, a glow discharge decomposition method using a silane-based raw material gas such as SiH4 and 5i2Hs and a carrier such as hydrogen. gas is introduced into the reaction vessel to cause glow discharge, or S i F4 and 5iCl
A mixed gas of a silicon halide such as + and hydrogen gas may be used, or a mixed gas of a silane gas and a silicon halide may be used. Furthermore, the n-type a-8i layer and the like can be formed not only by the glow discharge decomposition method but also by a physical method such as sputtering.

Nitrogen N is added to n-type a-3iSa-3 or μc-3i.
, carbon (C), and oxygen (0).

This increases the dark resistance of n-type a-3i etc. and increases the light s
1 characteristic can be reduced.

In order to make μc-8i and a-8i p-type, it is preferable to dope them with elements belonging to Group 1 of the periodic table, such as boron B1 aluminum A1, gallium Qa, indium ■n1, and thallium T1. , μc-8i
In order to make a-8i and a-8i n-type, it is preferable to dope it with an element belonging to Group V of the periodic table, such as nitrogen N1 phosphorus P, arsenic AS1 antimony sb, and bismuth 3i. By doping with this n-type impurity or n-type impurity, a barrier layer that prevents charge injection from the support into the charge transport layer can be formed.

μc-3i and a-8i themselves are somewhat n-type, but
The charge transport layer or barrier layer formed of μc-8i or a-3i is lightly doped (
10-1 to 10-3 at.

In this invention, the charge transport layer is μc-8i,
The layer thickness is 3 to 80 μm. By making the charge transport layer i-type, high resistance can be achieved. charge transport layer i
In order to form a mold, μC-3i may be lightly doped with an element belonging to Group 1 of the periodic table, or may be made to contain C, O, and N.

In addition, μC-8i has a small optical band gap and is highly sensitive to long wavelength light, so by forming the charge transport layer with μC-3i in this way, it is possible to absorb light from visible light to long wavelength light. .

Moreover, since μc-8i has few structural defects, carrier mobility is high and running properties are good. Therefore, carriers move with high efficiency in this charge transport layer. On the other hand, when the charge generation layer and the charge transport layer are all formed of a-3i, long wavelength light such as semiconductor laser light is not absorbed by these layers and reaches the support. This light is then reflected by the support and produces interference fringes in the image. However, in this invention, μC-8 is added to the charge transport layer.
Since i is used, the occurrence of such interference fringes is suppressed.

Incidentally, while μc-3i has the above-mentioned advantages, it also has the disadvantage of low dark resistance. To compensate for this drawback, 1. In this invention, C, O, N is added to μC-8i.
or make μC-81 i (intrinsic) type to increase the resistance. These C1○ and N may be uniformly distributed in the charge transport layer, but they may also be distributed so that their concentration changes in the layer thickness direction in all or part of the charge transport layer. In this case, the concentrations of C, O, and N are preferably changed so as to increase from the charge generation layer toward the conductive support. In this way, by changing the concentration of the doping element in the layer thickness direction, separation of the layers at the boundaries between the layers can be prevented. Also, C
, O, and N, the band gap of μc-3i is widened and the movement of carriers from the conductive support to the charge generation layer is suppressed. Since it is preferable that the region where movement is suppressed in this way is near the conductive support,
It is preferable to create a concentration distribution such that the concentrations of C, 0, and N become closer to the conductive support side.

Preferably, a surface layer is provided on the charge generation layer. Since μc-8i of the charge generation layer has a relatively large refractive index of 3 to 4, light reflection easily occurs on the surface. When such light reflection occurs, the ratio of the amount of light absorbed by the charge generation layer decreases, and light loss increases. For this reason, it is preferable to provide a surface layer to prevent reflection. Also, by providing the surface layer, the charge generation layer is protected from damage.

Furthermore, by forming the surface layer, the charging ability is improved, and the charge can be easily deposited on the surface. Materials forming the surface layer include Si3N+, SiO2, SiC, Al1
03, a-8iN:Hla-8iO:H, and a-8i
There are inorganic compounds such as C:H and organic materials such as polyvinyl chloride and polyamide.

[Example] FIGS. 4 to 6 are partial cross-sectional views showing an electrophotographic photoreceptor according to an example of the present invention. In the photoreceptor shown in FIG. 4, a charge transport WJ 22 is placed on a conductive support 21.
is formed, and charge generation @ is formed on the charge transport layer 22.
23 is formed.

In the photoreceptor shown in FIG. 5, a barrier layer 24 is formed between a conductive support 21 and a charge transport layer 22. In the photoreceptor shown in FIG. 6, a barrier layer 24 is formed between a conductive support 21 and a charge transport layer 22, and a surface layer 25 is further formed on a charge generation layer 23.

The charge transport layer 22 is made of μc-3i containing H, and has a layer thickness of 3 to 80 μm. This charge transport 1!22 can be made into an i-type by containing an element belonging to Group Ⅰ of the periodic table. Also, C,
The charge transport layer 22 can also be made to have high resistance by containing O and N. It is preferable that the concentrations of C, O, and N are changed in the layer thickness direction so that their concentrations increase from the charge generation layer 23 toward the conductive support 21.

The charge generation layer 23 is formed of n-type a-8i,
Its layer thickness is 1 to 10 μm.

Next, embodiments of the invention will be described.

Example 1 The inside of the reaction vessel was evacuated using a diffusion pump (not shown),
Create a vacuum of approximately 0.1 torr. Thereafter, the drum base is heated and maintained at about 400°C. Then 2008CCM
5i2Hs gas with a flow rate of , 82H6 gas with a flow rate ratio of 10-3 to this 3i2Hs gas flow rate, and 150SCC
M of 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. A high frequency power of 300 W at 13.56 MHz was applied to the electrode to generate plasma between the electrode and the drum base, and 1
A barrier layer 24 having a thickness of 1.6 μm was formed on the support 21 in 0 minutes.

After that, the flow rate of 5i2Hs gas was set to 500SCCM, 82
The flow rate of H6 gas is 2 as the flow rate ratio to 5i2Hs gas.
X10-', CH4 gas flow rate 250SCCM, H
2tj:1. (Set the D flow rate to 15008CCM,
These gases were introduced into the reaction vessel. The reaction pressure was set to 0.
By adjusting the high frequency power to 8 Torr and 1 KW, a charge transport layer 1i22 of 20 μm was formed in 4 hours.

After sono, S 12Hs jf (D flow rate 808ccM
, PH3 gas was set at a flow rate ratio of 10-5 to 5i2Hs gas, and these gases were introduced into the reaction vessel. The reaction pressure was adjusted to 0.3 torr and the high frequency power was adjusted to 100 W, and the charge generation layer 23 was formed in a thickness of 8 μm in 1 hour.

After that, the flow rate of 5i2Hs gas was changed to 300SCCM, CH
The flow rates of the four gases were set at 2508 CCM, and these gases were introduced into the reaction vessel. Adjust the reaction pressure to 1 Torr and the high frequency power to 300W, and the surface will be ready in 20 minutes! A 1.7 μl layer of I25 was formed.

The photoreceptor thus formed was mounted on a laser printer equipped with a semiconductor laser with a wavelength of 790 nm, and its electrostatic properties were measured. As a result, when the surface ratio was 500V,
The half-decreased exposure amount is 7.58 rO/d, and 35 era/d
The residual potential was 70V for the exposure amount. As described above, the photoreceptor according to this example has a high surface potential, a low residual potential, and excellent photoconductive properties.

The inside of the reaction vessel is evacuated by a diffusion pump (not shown),
Create a vacuum of approximately 0.1 torr. Thereafter, the drum base is heated and maintained at about 400°C. Then 2008CCM
5izHs gas with a flow rate of , B2Hs gas with a flow rate ratio of 10-3 to this 5i2Hs gas flow rate, and 11008
CH4 gas from CC 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.

Applying high frequency power of 300 W at 13.56 MHz to the electrode to generate plasma between the electrode and the drum base,
A barrier [124] having a thickness of 0.8 μm was formed on the support 21 in 5 minutes.

After that, the flow rate of 5i2Hs gas was changed to 500SCCM, N2
Gas flow rate is 100SCCM, H2 gas flow rate is 150SCCM.
These gases were introduced into the reaction vessel at a setting of 0.8 CCM. The reaction pressure was set to 0.8 Torr, the high frequency power was set to 1 KW as described above, and the film was formed for 1 hour. Next, a film was formed for 1 hour while high-frequency power was being applied and the flow rate of N2 gas was set to 80 SCC to 1 and the flow rates of other gases were the same as described above. Thereafter, the film was formed for 1 hour with the flow rate of N2 gas set to 508 CCM and the other gases set at the same flow rates as described above. After that, N2
The film was formed for 2 hours with the gas flow rate set at 208 CCM and the other gases set at the same flow rates as described above. In this way, charge transport @
22 was formed into a 20μ door.

After that, the flow rate of 5i2Hs gas was set to 100SCCM, PH
The flow rate of s gas is 5x1 as a flow rate ratio to 5i2Hs gas.
0-'', these gases were introduced into the reaction vessel.The reaction pressure was adjusted to 0.8 Torr, and the high frequency power was adjusted to IKW, and the charge generation layer 23 was formed to a thickness of 8 μm in 2 hours.

After that, the ill of 5i21-1s gas is 300SCCM
, CH4 gas were introduced into the reaction vessel with a flow rate of 3008 CCM. The reaction pressure is 1 Torr,
Adjust the high frequency power to 200W and remove the surface layer 2 in 15 minutes.
5 was formed to a thickness of 1 μm.

The photoreceptor formed in this manner has excellent photoconductive properties as in the first example.

[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 drawings]

FIG. 1 is a graph showing the relationship between doping ratio and electrical conductivity, FIG. 2 is a graph showing the relationship between doping ratio, activation energy, and optical band gap, and FIG. 3 is an electrophotograph according to the present invention. 4 to 6 are cross-sectional views showing an electrophotographic photoreceptor according to an embodiment of the present 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 substrate, 15: Heater, 16: High frequency power supply, 19; Gate pulp, 21: Support, 22;
charge transport layer, 23; charge generation layer, 24; barrier layer, 25;
Surface layer applicant agent Patent attorney Takehiko Suzue PH3/Si2H6 Figure 1] d Figure 3

Claims (4)

[Claims] (1) In an electrophotographic photoreceptor having a conductive support, a charge generation layer, and a charge transport layer disposed between the conductive support and the charge generation layer, the charge generation layer contains hydrogen. It is formed of n-type amorphous silicon containing
The charge transport layer is formed of microcrystalline silicon containing hydrogen and at least one element selected from carbon, oxygen, and nitrogen, and has a layer thickness of 3 to 80 μm. Photographic photoreceptor. (2) The electrons according to claim 1, wherein the concentration of carbon, nitrogen, or oxygen in the charge transport layer changes in the layer thickness direction such that the concentration thereof becomes higher on the support side. Photographic photoreceptor. (3) The charge transport layer contains at least one element selected from elements belonging to Group III of the periodic table. The electrophotographic photoreceptor according to item 1. (4) Claim 1, characterized in that a barrier layer is provided between the conductive support and the charge transport layer.
The electrophotographic photoreceptor described in .