JPS63244049A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide high resistance and superior electrostatic charge characteristics as well as to improve the traveling property of carriers by using superlattices each formed by laminating thin films having different optical band gaps in a photoconductive layer. CONSTITUTION:A photoconductive layer 3 is composed of an electric charge generating layer 6 and an electric charge retaining layer 5. The layer 6 is formed by alternately laminating thin amorphous Si films and thin microcrystal line Si films. The layer 5 is formed by alternately laminating thin microcrystal line Si films and thin films of amorphous Si contg. at least one among C, O and N. The crystallinity of each of the thin microcrystalline Si films in the layers 6, 5 varies continuously in the vicinity of the interface and each of the layers 5, 6 have a superlattice. Thus, an electrophotographic sensitive body having superior electrostatic chargeability, low residual potential and high sensitivity over a wide wavelength region to the near infrared region is obtd. The sensitive body also has satisfactory adhesion between the layers and sub strate and superior environmental resistance.

Description

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

(Prior art) Amorphous silicon (hereinafter referred to as a) containing hydrogen (H)
-St:H) has recently attracted attention as a photoelectric conversion material, and has been applied to photoreceptors in electrophotographic processes as well as solar cells, thin film transistors, image sensors, and the like.

Conventionally, CdS, ZnO, Ss, or S@-To has been used as a material constituting the photoconductive layer of an electrophotographic photoreceptor.
or inorganic materials such as P+7-H-vinylcarbazole (P
Organic materials such as VCz) or trinitrofluorenone (TNF) have been used. However, a −8
Compared to these inorganic or organic materials, 1:H is a non-polluting substance, so there is no need for recovery treatment, it has high spectral sensitivity in the visible light region, and it has a high surface roughness and good wear resistance. It has advantages such as excellent impact resistance. For this reason, a-8i:H is attracting attention as a photoreceptor material for electrophotographic processes.

This a-8i:H is being studied as a photoreceptor material based on the Karun system, but in this case, high resistance and photosensitivity are required as photoreceptor characteristics. However, it is difficult to satisfy both of these characteristics with a single photoreceptor, so 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. These requirements are met by creating a multilayer structure.

(Problems to be Solved by the Invention) By the way, a-8l:H is usually formed by a glow discharge decomposition method using a silane gas, but at this time,
a-81: Hydrogen is taken into HHX, and the difference in the amount of hydrogen greatly changes the stain and optical properties. That is, a
-81: When the amount of hydrogen that enters the H layer increases, the optical band gear lag becomes thicker, and a-8i: The resistance of H increases, but the photosensitivity to long wavelength light decreases accordingly. Therefore, it is difficult to use it, for example, in a radar beam printer equipped with a semiconductor radar.

Also, a-8t: HI! When the hydrogen content in X increases, depending on the film formation conditions, (SiH2)n and 8112
In some cases, a bond structure such as occupies most of the area in the film. In this case, the number of gates increases and the number of silicon dangling bonds increases, resulting in deterioration of the photoconductive properties and the use as an electrophotographic photoreceptor. On the contrary, a
A reduction in the amount of hydrogen incorporated into -8l:H reduces the optical bandgear lag and its resistance, but increases the photosensitivity to long wavelength light. However, when the hydrogen content is low, there is less hydrogen to combine with and reduce silicon dangling ends. For this reason, the mobility of the generated carriers is reduced, the life span is shortened, and the photoconductive properties are deteriorated, making it difficult to use as an electrophotographic photoreceptor.

In this way, the photoconductive layer of the electrophotographic photoreceptor can be formed into a single a-8
If the a-8i :H layer is constructed only, the characteristics will vary greatly depending on the manufacturing conditions of the a-8i :H layer, and there is a problem that desired characteristics cannot be obtained.

The present invention has been made in view of such circumstances, and
To provide an electrophotographic photoreceptor with excellent charging ability, low residual potential, high photosensitivity over a wide wavelength range up to the near infrared region, good adhesion to a substrate, and excellent environmental resistance. The purpose is to

[Structure of the Invention] (Means for Solving the Problems) As a result of extensive research, the present inventor has constructed a photoconductive layer of an electrophotographic photoreceptor with a charge retention layer, a charge generation layer, and K. The present inventors have discovered that the above object can be achieved by stacking a plurality of predetermined semiconductor films, that is, forming a region with a superlattice structure, and have completed the present invention.

That is, the electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor comprising an electrically conductive support and a photoconductive layer, the photoconductive layer comprising a charge generation layer and a charge retention layer, The generation layer is formed by alternately laminating amorphous silicon thin films and microcrystalline silicon thin films, and the charge retention layer is formed by laminating a microcrystalline silicon thin film and at least one element selected from carbon, oxygen, and nitrogen. The microcrystalline silicon thin film of the charge generation layer and the charge retention layer has a crystallinity continuously changing in the vicinity of the interface between the microcrystalline silicon thin films of the charge generation layer and the charge retention layer. do.

The microcrystalline silicon (μe-8t) used in the present invention is thought to be formed by a mixed layer of microcrystalline silicon and amorphous silicon with a grain size of approximately several tens of angstroms, and is as follows: It has the following physical properties.・Firstly, in X-ray diffraction measurement, 2θ is 28 to 28.5°
It shows a nearby crystal diffraction pattern and is clearly distinguished from the amorphous a-81 in which only a halo appears. Secondly,
The dark resistance of .mu.c-8i can be adjusted to 1010 .OMEGA..multidot.1 or higher, and it can be clearly distinguished from I-lycrystalline silicon, which has a dark resistance of 1050 .OMEGA..multidot.

The optical band gear lag CEg0) of μa-81 used in the present invention is preferably set to, for example, 1.55 aV. However, it can be set arbitrarily within a certain range.

In order to obtain desirable E and @, it is preferable to add a predetermined amount of hydrogen to each and use them as μa-81:H. This compensates for the dangling gates of the cricon, balances the dark resistance and the bright resistance, and improves the photoconductive properties.

The crystallinity of the microcrystalline silicon thin film constituting the charge generation layer is preferably 60 to 90%, more preferably 60 to 80%.
% range.

The concentration of carbon, oxygen, and nitrogen contained in the amorphous silicon thin film constituting the charge retention layer is preferably 0.1 to 40 atoms, more preferably 0.5 to 30 atoms.

(Function) In the electrophotographic photoreceptor of the present invention, since the photoconductive layer is provided with the superlattice structure, carriers generated in this region have a long life and a high mobility. Although the logic thereof has not yet been fully established, there is no doubt that it is a quantum effect due to the periodic well type I-tensile characteristic of the superlattice structure, and this is particularly referred to as the superlattice effect.

In this way, the mobility of carriers in the photoconductive layer is large.
Furthermore, if the life of the carrier becomes longer, the sensitivity of the electrophotographic photoreceptor will be significantly improved due to K.

(Example) FIG. 1 is a diagram showing a cross-sectional structure of an electrophotographic photoreceptor according to an example of the present invention. In the same figure, conductive support 1
A barrier layer 2 is formed thereon, and a photoconductive layer 3 consisting of a charge retention layer 5 and a charge generation layer 6 is formed thereon.

Further, a surface layer 4 is formed on the charge generation layer 6.

Note that both the charge retention layer 5 and the charge generation layer 6 have a superlattice structure.

Hereinafter, the structure of the electrophotographic photoreceptor shown in FIG. 1 will be explained in detail.

The conductive support 1 usually consists of a drum made of aluminum.

The barrier layer 2 may be formed using μe-81 or a-8t:H, or a-BN:H (amorphous boron to which nitrogen and hydrogen are added). Furthermore, an insulating film may be used. For example, μe-8i:H and a-8
By including one or more elements selected from carbon C1 nitrogen N and oxygen O in 1:H, a high-resistance insulating barrier layer can be formed.

The thickness of the barrier layer 2 is preferably 100X to 10 μm.

The barrier layer 2 is formed to enhance the charge retention function of the surface of the photoreceptor by suppressing the flow of charges between the conductive support 1 and the charge generation layer 5, thereby increasing the charging ability of the photoreceptor. It is something that will be done. Therefore, when a Carlson type photoreceptor is constructed using a semiconductor layer as a barrier layer, the barrier layer 2 is made to be P type or N type in order not to reduce the ability to retain charges charged on the surface. That is, when the surface of the photoreceptor is positively charged, the barrier layer 2 is of P type to prevent electrons that neutralize the surface charge from being injected into the charge generation layer.

Conversely, when the surface is negatively charged, the barrier layer 2 is made of N type,
This prevents holes that neutralize surface charges from being injected into the charge generation layer. Since carriers injected from the barrier layer 2 become noise with respect to carriers generated in the charge generation layer 6 upon incidence of light, preventing carrier injection as described above improves sensitivity. Note that μe-8i:H
! a-8i: To make Ht-P type, elements belonging to Group Ⅰ of the periodic table, such as boron B, aluminum A
t, , f licum Ga, indium In, and thallium T
It is preferable to dope t or the like. Also, μc-
81:H-? a-8t: In order to make H the N type, elements belonging to Group V of the periodic table, such as nitrogen, phosphorus P, arsenic A
It is preferable to dope with s, antimony sb, bismuth B1, etc.

The charge generation layer 6 generates carriers when light is incident thereon, and carriers of one polarity neutralize the charges on the surface of the photoreceptor, while the other carriers travel within the charge retention layer 5. and reaches the conductive support 1.

The charge retention layer 5 and the charge generation layer 6 are constructed by alternately laminating two types of thin layers. These thin layers have different optical bandgaps, each having a thickness of 30 to 500×
within the range of

Ideally, the superlattice structure constituting the photoconductive layer should have, for example, thin films with different optical band gaps forming a discontinuous periodic potential, as shown in FIG.

However, in order to deposit such a superlattice structure, it is necessary to purge the gas in the reaction chamber after each thin film is deposited to prevent impurities from entering the thin film during the next deposition. However, there are disadvantages in that the film forming time is extremely long and mass productivity is poor. Furthermore, when depositing a film using Glazma CVI), ion bombardment (ion 2 bombardment) constantly occurs on the film deposition surface, which causes impurities to diffuse into the thin film, resulting in the discontinuity shown in Figure 2. A periodic potential cannot be formed.

In contrast, in the superlattice structure according to the present invention, as shown in FIG. 3, the degree of crystallinity, that is, the optical band gap, near the interface of each thin film is continuously changed. Such a superlattice structure is created by slightly lowering the high frequency power to weaken the ion 2 impurity, introducing a large amount of H2 gas, and appropriately changing the flow rate of gas containing impurities while keeping the high frequency power constant. Alternatively, it can be obtained by changing the high frequency power while keeping the gas flow rate constant. By forming a film by such a method, the ion bond is weakened, and a periodic potential as shown in FIG. 4 in which the characteristics near the interface change continuously can be obtained.

In this way, by adopting a superlattice structure in which the degree of crystallinity and therefore the optical band gap are continuously changed near the interface of the thin film, the thin film can be deposited one after another without waiting for the deposition conditions to stabilize. Since the film can be formed as described above, the film forming time can be significantly shortened, resulting in excellent mass productivity. Furthermore, since the film formation is continuous, the adhesion between each thin film is improved.

As explained above, by stacking thin layers with mutually different optical band gaps, the optical band can be set as a standard for layers with a small optical band gap, regardless of the size of the optical band gap itself. A superlattice structure is formed having periodic I-tensional barriers in which the large gap layer serves as a barrier. In this superlattice structure, since the barrier thin film is extremely thin, carriers pass through the barrier and travel through the superlattice structure due to the carrier tunneling effect in the thin layer. Furthermore, in such a superlattice structure, a large number of carriers are generated by incident light. Therefore, it has high photosensitivity. Note that by changing the bandgap and layer thickness of the thin layer of the superlattice structure, the apparent bandgap of the layer having the heterojunction superlattice structure can be freely adjusted.

a-81 constituting the charge retention layer 5 and charge generation layer 6:
The hydrogen content in H and μa-8t:H is 0.
01 to 30 atomic % is preferable, and 1 to 25 atomic % is more preferable. Dangling silicon due to such hydrogen content? The dark resistance and bright resistance are balanced, and the photoconductive properties are improved.

a-81: To form a H layer by glow discharge decomposition method, 7R gases such as SiH4 and 512H6 are introduced into the reaction chamber as raw materials, and H is formed in the thin layer by glow discharge using high frequency. can be added. If necessary, hydrogen or helium gas can be used as a carrier gas for silanes.

On the other hand, silicon halide such as SiF4 gas and ssct4 gas can be used as the raw material gas. Further, a-8i:H containing H can be similarly formed by reacting with a mixed gas of silane gas and silicon halide gas. Note that these thin films can be formed not only by the glow discharge decomposition method but also by a physical method such as sputtering.

Similarly to a-8f:H, the pc-8f layer can also be formed by high-frequency glow discharge decomposition using silane gas as a raw material. In this case, the temperature of the support is set to a-81
: When forming H, set high and high frequency power.
-81: When set higher than in the case of H, μe-81:
It becomes easier to form H. Furthermore, by increasing the support temperature and high frequency power, the flow rate of raw material gas such as silane gas can be increased, and as a result, the film formation rate can be increased.

In addition, by using gas obtained by diluting high-order silica/gas such as 5IH4 and S1□H6 with hydrogen,
μc-81:H can be formed with higher efficiency.

To make pc-8t:H and a-81:H p-type, elements belonging to Group Ⅰ of the periodic table, such as boron B, aluminum, gallium Ga, indicum In, and thallium Tt, etc. It is preferable to dope
μe-81: H and a-8t: In order to make H the n-type, an element belonging to Group V of the periodic table, such as nitrogen N,
Phosphorus P, arsenic As, antimony Sb, and bismuth B!
It is preferable to dope. This doping with pm impurities or n-type impurities prevents charges from moving from the support side to the photoconductive layer. On the other hand, pc-8
1:H and a-81:H, carbon C1 nitrogen N and oxygen 0
By containing at least one element selected from the following, high resistance can be achieved.

The surface charge retention ability can be increased.

A surface layer 4 is provided on the charge generation layer 6.

Since a-81:H and the like of the charge generation layer 6 has a relatively large refractive index of 3 to 3.4, 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 the surface layer 4 to prevent reflection. Further, by providing the surface layer 4, the charge generation layer 6 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.

The material forming the surface layer is a-8IN:Hla-
These include inorganic compounds such as 810:H, and a-SiC:H, and organic materials such as polyvinyl chloride and polyamide.

When the surface of the electrophotographic photoreceptor constructed in this manner is charged with a positive voltage of about 500 V by corona discharge, a potential barrier is formed. When light (hv) is incident on this photoreceptor, carriers of electrons and holes are generated in the charge generation layer 6. Electrons in this conduction band are moved by the electric field in the photoreceptor,
The holes are accelerated toward the surface layer 4 side, and the holes are accelerated toward the conductive support 1 side. In this case, due to the quantum effect in the potential well layer of the charge retention layer, the lifetime of the carriers is 55% compared to the case of a single layer without a superlattice structure.
It is 10 to 10 times longer. Furthermore, in a superlattice structure, a periodic barrier layer is formed due to bandgap discontinuity, but carriers easily pass through the bias layer due to the tunnel effect, so the effective carrier mobility is The mobility is similar to that in bulk, and carrier mobility is excellent. As described above, the superlattice structure in which thin layers with different optical and transmissive caps are laminated can provide high photoconductivity and provide clearer images than conventional photoreceptors.

Referring to FIG. 4, an apparatus and a manufacturing method for manufacturing the electrophotographic photoreceptor of the above embodiment by a glow discharge method will be described below. In the same figure, gas? Empe21.22,23.
24, for example, 81H, respectively.

A raw material gas such as B2H61H21CH4 is contained.

These gases in the pump are connected to the pallet 226 for flow rate adjustment.
and is supplied to a mixer 28 via a pipe 27. A pressure gauge 25 is installed in each depot.
By adjusting the valve 26 while monitoring the pressure gauge 25, the flow rate and mixing ratio of each raw material gas supplied to the mixer 28 can be adjusted.

The mixed gases are supplied to a reaction vessel 29 in a mixer 28 . A rotating shaft 30 is rotatably attached to the bottom 3 of the reaction vessel 29 in a vertical direction. The rotating shaft 30
A disk-shaped support 32 is fixed to the upper end of the rotary shaft 30 with its surface perpendicular to the rotating shaft 30. Inside the reaction vessel 29, a cylindrical electrode 33 is installed on the bottom 31 with its axial center aligned with the axial center of the rotating shaft 30. A drum base 34 of a photoreceptor is placed on a support base 32 with its axial center aligned with the axial center of the rotating shaft 30, and a heater 35 for heating the drum base is disposed inside the drum base 34. has been done. A high frequency power source 3 is connected between the electrode 33 and the drum base 34.
6 is connected so that a high frequency current is supplied between the electrode 33 and the drum base 34. Rotating axis 3
o is rotationally driven by a motor 38. The pressure inside the reaction vessel 29 is monitored by a pressure gauge 37, and the reaction vessel 29 is connected via a dirt pulp 38 to a suitable evacuation means such as a vacuum pump.

When manufacturing a photoreceptor using the above-mentioned manufacturing apparatus, after installing the drum base 34 in the reaction vessel 29,
39 to evacuate the inside of the reaction vessel 29 to a pressure of about Q,1 Tart or less. Next, yJ? Npe 21.22,
From 23 and 24, required reaction gases are mixed at a predetermined mixing ratio and introduced into the reaction vessel 29. In this case, reaction vessel 2
The flow rate of the gas introduced into the reaction vessel 9 is such that the pressure inside the reaction vessel 29 is 0.
1 to 1. Set it to OTorr. Then,
The motor 38 is operated to rotate the drum base 34, the heater 35 heats the drum base 34 to a constant temperature, and the high frequency power supply 35 is used to heat the stain pole 33 and drum base 34.
A high frequency current is supplied between the two to form a glow discharge between the two. As a result, a-8l is placed on the drum base 34:
H is deposited. In addition, the raw materials are placed in a N20° plate 3. NO
By using □+ N2* CH4, C2H4# O□ gas, etc., these elements can be incorporated into a-81:H.

As described above, since the electrophotographic photoreceptor according to the present invention can be manufactured using a closed system manufacturing apparatus,
Safe for humans.

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

Test Example 1 An aluminum drum base with a diameter of 80 fl and a width of 350 m, which has been subjected to acid treatment, alkali treatment, and sandblasting treatment, is installed in the reaction vessel in order to prevent interference as necessary. The vacuum was evacuated to -5 torr. While heating the drum base to 250 °C and rotating it at 10 rpm, 5iI (4 gas was introduced into the reaction vessel at a flow rate of 5008 CCM and BH gas was introduced into the reaction vessel at a flow rate of 10-s at a flow rate ratio of SiH4 to gas, and the pressure inside the reaction vessel was was adjusted to 1 Torr.Then, a high frequency power of 13.56 MHz was applied to generate a glazma, and p-type A-81:
An H barrier layer was formed.

Next, the SiH4 gas was set at 50 SCCM, the H2 gas was set at 5008 CCM, and a high frequency power of 1 kW was applied. Next, CH4ff gas was introduced for 2 minutes while high frequency power was applied. By repeating these operations, a 20-μm charge-holding film consisting of a μc-81:H thin film (crystallinity: 60%) in which the crystallization near the interface changes continuously and an a-stc:H thin film is formed. formed a layer.

Next, 5IR4 gas was set to 400 SCCM, H2 gas was set to 5008 CCM, and a high frequency power of 300 W was applied to form a 50X a-8i:H thin film. Then, S
50 SCCM of iH4 gas, 500 SCCM of H2 gas
8 CCM, soowO high frequency power is applied, 100
A μe-81:H thin film (crystallinity: 65%) of X was formed. These operations were repeated to form a charge generation layer of 5 μm.

When the surface of the photoreceptor thus formed is positively charged at about 500 V and exposed to white light, this light is absorbed by the charge generation layer and carriers of electron-hole pairs are generated. In this test example, a large number of carriers were generated, the carriers had a long life, and high running performance was obtained. This allows you to obtain clear, high-quality images. In addition, when the photoreceptor manufactured in this test example was repeatedly charged, the reproducibility and stability of the transferred image were extremely good, and the durability such as corona resistance, moisture resistance, and abrasion resistance was also improved. has been proven to be superior.

Test Example 2 An electrophotographic photoreceptor was manufactured in the same manner as Test Example 1, except that an a-3IN:H thin film was formed in place of the a-Sic:H thin film constituting the charge retention layer. In addition, a-
The 8IN:H thin film was obtained by applying RF power for 5 min and then introducing 208 CCM f7) N2 gas while keeping the RF power applied.

When an image was formed using this photoreceptor in the same manner as in Test Example 1, a clear and high quality image was obtained.

Test Example 3 An element photographic photoreceptor was produced in the same manner as in Test Example 1, except that the surface layer was composed of a-8iC:H with an O25 μm and the photoconductive layer was formed as follows.

5IH4 gas 250SCCM, N2 gas 500
8CCM.

CH4 gas was introduced at 50 SCCM, the pressure inside the reaction vessel was set to I Torr, and a high frequency power of 200 W was applied to form a 50X a-8iC:H thin film. Next, 0M4 gas t-o, SiH4 gas t-5
0SCCM, apply sow high frequency power, 1
A μa-81:H thin film (crystallinity 60%) of 00X was formed.

These operations were repeated to form a charge retention layer with a thickness of 18 μm.

Next, 150SCCM of 5IH4 gas and 50SCCM of N2 gas.
0SCCM, and a high frequency power of 300 W was applied for 1 to 2 minutes.

Next, SiH4 gas was used as t-50SCCM, and a high frequency power of 800 W was applied for 5 minutes. By repeating this operation, μa-
It consists of an 8i:H thin film (crystallinity of 260%) and an a-81:H thin film. A charge generation layer of 5 μm was formed.

When an image was formed using this photoreceptor in the same manner as in Test Example 1, a clear and high quality image was obtained.

Test Example 4 Instead of the a-81C:H thin film constituting the charge retention layer, a
An electrophotographic photoreceptor was manufactured in the same manner as in Test Example 3 except that a -8IN:H thin film was formed. In addition, a-8
IN:H thin film is 5IH4, f, S'fc 250 S
CCM, H,'jfxf500SCCM1N2 gas 1
This was obtained by introducing 20 SccM, respectively, and applying 300 W of high frequency power.

When an image was formed using this photoreceptor in the same manner as in Test Example 1, a clear and high quality image was obtained.

Test Example 5 An electrophotographic photoreceptor was manufactured by forming a barrier layer and a charge retention layer in the same manner as in Test Example 1, and forming a charge generation layer and a surface layer in the same manner as in Test Example 3.

When an image was formed using this photoreceptor in the same manner as in Test Example 1, a clear and high quality image was obtained.

Test Example 6 An electrophotographic photoreceptor was manufactured by forming a barrier layer and a charge retention layer in the same manner as in Test Example, and forming a charge generation layer and a surface layer in the same manner as in Test Example. make use of,
When an image was formed in the same manner as in Test Example 1, a clear and high quality image was obtained.

Nine test examples have been described above in which the photoconductive layer is composed of two types of thin films, but it is not Kfa, and three or more types of thin IX
T-layers may be used, and the boundaries between thin films having different K and optical band ears may be formed.

[Effects of the Invention] According to the present invention, the optical band gear lugs use superlattice structure gold formed by laminating different thin films in the photoconductive layer, and the carrier has high runnability and high resistance. An electrophotographic photoreceptor with excellent charging characteristics can be obtained.

In particular, it adopts a structure in which the crystallized gold is continuously changed near the interface of the microcrystalline silicon thin film, making it excellent for mass production.Also, because the film formation is continuous, the adhesion between each thin film is good. It is. Furthermore, the electrophotographic photoreceptor of the present invention has the advantage that by appropriately combining materials for forming a thin at, a photoreceptor having optimal photoconductive properties for light in any wavelength band can be obtained. be.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an electrophotographic photoreceptor according to an embodiment of the present invention, FIGS. 2 and 3 are diagrams showing energy bands of a superlattice structure, and FIG. 1 is a diagram showing an apparatus for manufacturing a photographic photoreceptor. DESCRIPTION OF SYMBOLS 1... Conductive support, 2... Barrier layer, 3... Photoconductive layer, 4... Surface layer, 5... Charge retention layer, 6...
Charge generation layer. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 13

Claims (7)

[Claims] (1) In an electrophotographic photoreceptor having a conductive support and a photoconductive layer, the photoconductive layer is composed of a charge generation layer and a charge retention layer, and the charge generation layer is composed of an amorphous silicon thin film and a microstructure. The charge retention layer is formed by alternately laminating microcrystalline silicon thin films and amorphous silicon thin films containing at least one element selected from carbon, oxygen, and nitrogen. 1. An electrophotographic photoreceptor, characterized in that the degree of crystallinity in the vicinity of the interface between the microcrystalline silicon thin film of the charge generation layer and the charge retention layer changes continuously. (2) The electrophotographic photoreceptor according to claim 1, wherein the thin film has a thickness of 30 to 500 Å. (3) The electrophotographic photosensitive layer according to claim 1 or 2, wherein the photoconductive layer contains at least one element selected from elements belonging to Group III and Group V of the periodic table. body. (4) A patent claim characterized in that a barrier layer made of an amorphous material or a semiconductor material in which at least a portion thereof is microcrystalline is formed between the conductive support and the photoconductive layer. The electrophotographic photoreceptor according to item 1. (5) The electrophotographic photoreceptor according to claim 4, wherein the barrier layer contains at least one element selected from elements belonging to Group III and Group V of the periodic table. (6) The electrophotographic photoreceptor according to claim 4 or 5, wherein the barrier layer contains at least one element selected from carbon, oxygen, and nitrogen. (7) The electrophotographic photoreceptor according to claim 1, wherein a surface layer is formed on the photoconductive layer.