JPS63135953A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the titled body having high optical sensitivity and to reduce residual voltage by laminating at least an amorphous silicon layer and an amorphous silicon carbide layer contg. group IIIa elements of a periodic table on a conductive substrate in this order, and by generating substantially an light carrier at the amorphous silicon carbide layer. CONSTITUTION:The titled body is formed by selecting the amorphous silicon carbide layer 5 composed of a-SiC layer contg. the group IIIa elements of the periodic table of 0.1-10,000ppm as the light carrier generating layer, and by combining said layer 5 with the amorphous silicon layer 6 composed of a-Si layer and by laminating them as shown by the figure. At this time, the a-Si layer 6 has the functions of transferring the carrier generated at the a-SiC layer 5 and maintaining voltage of the titled body, thereby retarding the injection of the carrier from the substrate 1 to the a-SiC layer 5. Thus, the trapping of carrier in the inside of the a-Si layer is remarkably lessened whereby the high optical sensitivity of the titled body is obtd., and the residual voltage of the titled body is reduced.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an electrophotographic photoreceptor that has increased photosensitivity to long-wavelength light and increased charging ability, and is particularly suitable as a photoreceptor for use in a laser beam printer. be.

(Prior art and its problems) In recent years, electrophotographic photoreceptors have made remarkable progress, and the development of ultra-high-speed copying machines and laser beam printers is actively underway. Because they are used in In response to this demand, hydrogenated amorphous silicon is attracting attention because it has excellent heat resistance, wear resistance, non-pollution properties, and photosensitivity characteristics.

Such amorphous silicon (hereinafter abbreviated as a-Si)
As an electrophotographic photoreceptor, a laminated type photoreceptor as shown in FIG. 2 has been proposed.

According to FIG. 2, a conductive substrate such as aluminum (
1) A-Si carrier injection blocking layer (2) on top, a-S
An i-carrier generation layer (3) and a surface protection layer (4) are sequentially laminated, and this carrier injection blocking layer (2) is formed on the substrate (1).
) is formed to increase the surface potential by blocking the injection of carriers from N(4), and a highly hard material is used for the surface protection N(4) to increase the durability of the photoreceptor.

On the other hand, germanium element (
A photoreceptor has also been proposed that contains Ge) to increase the photosensitivity in the wavelength range of 600 to 850 ns+, thereby making it suitable for semiconductor laser beam printers.

However, with the latter photoreceptor, the photosensitivity peak shifts to longer wavelengths, but on the other hand, the carrier generation layer (
The problem of 3) is that the dark conductivity increases rapidly, which lowers the surface potential, and as a result, it becomes difficult to obtain a high-density image.

To solve this problem, a second amorphous silicon carbide layer, an amorphous silicon germanium layer, and a first amorphous silicon carbide layer (hereinafter referred to as amorphous silicon carbide) are formed on the substrate.
A photoreceptor made by sequentially laminating layers of
This is proposed in Publication No. 44.

That is, the first a-5iC layer is the above-mentioned surface protective layer (4).
Formed for the same purpose as , it stabilizes the repeated characteristics of charging and optical attenuation, and increases wear resistance and heat resistance.
The amorphous silicon germanium layer (hereinafter amorphous silicon germanium is abbreviated as a-5iGe) is a photoconductive layer that exhibits high photoconductivity for long wavelength light, and the second a-5iC layer is used for potential retention and carrier transport. It has both functions, and has the function of efficiently and quickly injecting photocarriers generated in the a-5iGe layer into the substrate.

However, according to this laminated photoreceptor, the second a-
SiC14 improves potential retention and increases the surface potential, which makes it possible to obtain high-density images, but on the other hand, carrier movement occurs due to the carbon content in this a-SiC layer. The degree of the carrier tends to be lower than that of a-5i, and this causes the carrier to
It is trapped in the iC layer, and as a result, it is difficult to achieve high photosensitivity and reduce residual potential.

Furthermore, semiconductor laser beam printers have a problem in that because their light source is coherent light, interference fringes are likely to occur in images. The cause of this interference fringe pattern is that coherent light reaches the substrate, and the reflected light on the substrate interferes with the incident light. To solve this problem, the substrate surface is processed to create the desired surface. It has been proposed to set the roughness so that the light reaching the substrate is diffusely reflected. However, this surface roughening treatment inevitably increases manufacturing costs, and a solution that eliminates the need for this treatment is desired.

(Objective of the Invention) Therefore, the present invention was completed in view of the ridges, and its purpose is to prevent photoexcited carriers from being trapped in the layer region of the photoreceptor, thereby achieving high photosensitivity and low residual potential. It is an object of the present invention to provide an electrophotographic photoreceptor that can achieve a reduction in surface potential and a high surface potential.

Another object of the present invention is to provide an electrophotographic photoreceptor that has enhanced photosensitivity in the wavelength range of 600 to 850 nm and is suitable for use in semiconductor laser beam printers.

Still another object of the present invention is to provide an electrophotographic photoreceptor which is free from interference fringe patterns in images and which achieves cost reduction.

(Means for Solving the Problems) According to the present invention, at least an a-5i layer and a thickness of 0.1 to 10. Periodic Table IIIa of OOOppm
a-SiC layers containing group elements are sequentially stacked and a-
Provided is an electrophotographic photoreceptor characterized in that photocarriers are substantially generated in the SiC layer.

The present invention will be explained in detail below.

The basic layer structure of the electrophotographic photoreceptor of the present invention is as shown in FIG.
．． 000ppm of Group 111a elements of the periodic table (hereinafter referred to as I
It is possible to select an a-SiC layer (5) containing a group IIa element (abbreviated as group IIa element), combine this layer (5) with an a-Si layer (6), and arrange the stacking order as shown in Figure 1. is important.

That is, according to the experiments of the present inventors, this a-SiC layer (
When the spectral sensitivity characteristics of 5) were measured, it was found that the photosensitivity was particularly high in the wavelength range of 650 to 850 nm.
It has been found that this makes the photoreceptor suitable for semiconductor laser beam printers.

To explain the above point in detail, the spectral sensitivity of the a-5i layer decreases rapidly in the long wavelength region of 700 nm or more, whereas carbon is added to the a-Si layer as a main constituent element and 0. .1 to 10,000 ppm IIIa
When group elements are included, the photosensitivity is inferior to that of the a-Si layer in the short wavelength region, but on the other hand, the recovery of photosensitivity becomes remarkable in the long wavelength region, especially in the wavelength region of 700 nm or more, the a-Si layer It has been found that the photosensitivity can be significantly increased compared to the conventional method.

Based on this knowledge, < II according to the a-SiC layer (5)
This is completely contrary to the conventionally well-known phenomenon that the spectral sensitivity peak of the a-SiC layer that does not contain a group Ia element shifts to the shorter wavelength side compared to the a-Si layer, and the photosensitivity characteristics generally decrease. If we infer this point based on the experimental results conducted by the present inventors, it is clear that the a-SiC layer contains IIIa.
When group elements are contained within a specified range, the film quality is improved throughout the layer, the mobility of excited carriers increases, the photoconductivity improves, and the film penetrates deep into the film in the direction of the layer thickness. It is believed that the effect of significantly increasing photosensitivity characteristics for long wavelength light can be obtained.

The NLA group elements include B, AI+Ga+In, etc.
Among these, B is desirable because it has excellent covalent bonding properties and can sensitively change semiconductor properties. Further, the content of this Group IIIa element is 0.1 to 10,000 oom, preferably 1 to 1
,000ppm, optimally 10 to 1,000ppm
If it is less than 0.1pp+n, the spectral sensitivity will not recover sufficiently on the long wavelength side and the
It is inferior to the a-5i layer at wavelengths of nm or more, and 10,
If it exceeds 000 ppm, the dark resistivity decreases and the ratio of dark resistivity to bright resistivity decreases, degrading electrophotographic characteristics.

Furthermore, when the a-5iC layer (5) and the a-3i layer (6) are combined in the stacking order shown in FIG.
is a-SiC1! ! It has the function of transporting the carriers generated in step (5) and holding the potential, and can also have the function of preventing carriers from being injected from the substrate (1) into the a-SiC layer (5).

In this way, the a-5i layer (6
), the carrier mobility of a-3i itself is relatively high, which greatly reduces the possibility of carriers being trapped inside the a-Si layer, and as a result,
High photosensitivity and reduced residual potential can be achieved.

According to the present invention, when the a-5i layer (6) is formed as described above, it is difficult to increase the charging ability compared to the a-SiC layer. It is supplemented with

That is, a-3ili! (6) does not contain carbon, so it is not possible to set the dark conductivity to a sufficiently small value, but instead, the a-SjC layer (5) contains carbon, which makes the photoreceptor can increase the charging ability of

Furthermore, according to the present invention, it is important that optical carriers are substantially generated in the a-SiC layer (5) by the stacking order shown in FIG. As a result, the problem of interference fringes in the image is solved.

Although the electrophotographic photoreceptor of the present invention is assembled based on the idea as described above, the object of the present invention can be advantageously achieved by making various limitations as described below.

Regarding the a-3iC layer (5), the content ratio of Si element to C element is within the range of 1:1 to 100:1, preferably 3
:1 to 100:1. Within this range, the dark conductivity can be sufficiently reduced and the charging ability can be improved.

Further, the thickness of the a-SiC layer (5) is appropriately determined so that this layer can essentially serve as a photocarrier generation layer, but the inventors conducted experiments with the thickness changed in a number of ways. As a result, if the thickness of the a-SiC layer (5) is set so that the transmittance of the a-SiC layer (5) to incident light is 30% or less, preferably 20X or less, no light will reach the substrate (1). As the thickness of this layer (5) increases, its transmittance can be reduced, but on the other hand, the residual potential of this photoreceptor tends to increase. Therefore, the a-SiC layer (
The thickness of 5) is determined by the transmittance and residual potential of the layer, and according to repeated experiments conducted by the present inventors, the thickness is 1 to 10 μm, preferably 1 to 30 μm,
It has been found that the optimum thickness may be set within the range of 1 to 10 μm.

Hydrogen element (H) is included as an element for dangling bond termination so that a-SiC1i (5) has photoconductivity.
and halogen elements, and the content of these elements is 5 to 50 atoms χ, preferably 5 to 40 atoms χ, optimally 10
It is preferable to have χ to 30 atoms, and H element is usually used. Since this H element is easily taken into the terminal portion, the localized level density in the band gap is reduced, thereby providing excellent semiconductor characteristics.

In addition, a part of this H element may be replaced with a halogen element, which lowers the localized level density and increases photoconductivity and heat resistance (temperature characteristics), and the substitution ratio is dangling. Out of all the elements for bond termination, 0.01 to 50 atoms χ, preferably 1 to 30 atoms 2 are preferred. In addition, this halogen element includes F, C1゜Br, I, At, etc.
In particular, the use of F is desirable because its large electronegativity increases the bonding between atoms, thereby providing excellent thermal stability.

It is necessary that the a-Si layer (6) also contain a dangling bond termination element, and the type and content of the element are determined as appropriate under the same conditions as the a-SiC layer (5) described above.

According to the present invention, based on the laminated type photoreceptor having the above-described two-layer structure, electrophotographic characteristics can be improved by laminating other layers as shown in FIGS. 3 to 5.

That is, according to FIG. 3, the substrate (1) and the a-Si layer (6)
A carrier injection blocking layer (7) is interposed between the a-Si
efficiently injecting carriers from the layer (6) into the substrate (1) and blocking injection of carriers from the substrate (1);
This allows the surface potential to be further increased. This carrier injection blocking layer (7) is made of an organic material such as polyimide resin, SiO□+ S I O+ A ] z 03
1 S i C + 5iiN4 + amorphous carbon,
It is formed of an inorganic material such as Bj;i, a-5iC.

In forming this carrier injection blocking layer (7) from a semiconductor material, the conductivity type is controlled to be P type when the photoreceptor is charged to positive polarity, and to N type when charged to negative polarity. It is preferable to control this, and thereby the carrier injection blocking effect is further improved. For example, this P-type semiconductor material contains Group IIIa elements of the periodic table such as B, and N
The a-type semiconductor material contains elements of Group Va of the periodic table such as P within a range of 50 to 110,000 pp.
There is St or a-SiC.

Furthermore, when a photoconductive amorphous layer containing carbon is formed on the surface side of the photoreceptor as shown in FIGS. -Hardness is smaller than that of the 3iC surface protective layer,
Thereby, even if the surface is repeatedly polished and regenerated using an abrasive or the like, the initial characteristics of the photoreceptor can be maintained without being limited in the amount of polishing. For example, even if the surface deteriorates due to exposure to corona discharge or filming on the surface of the photoreceptor due to the resin component of the developer, good images can be stably supplied over a long period of time by this polishing regeneration.

Furthermore, according to FIG. 4, a surface protection @ (8) is formed on the surface of the basic laminated photoconductor shown in FIG. Various materials can be used as long as they have high corrosion resistance and hardness properties. For example, the carrier injection prevention N(7)
The same inorganic or organic materials used in the photoreceptor can be used, thereby increasing the durability and environmental resistance of the photoreceptor.

Furthermore, a carrier injection blocking layer (7) as shown in FIG.
) and a surface protective layer (8), the electrophotographic properties can be further improved.

In addition, a bonding layer (6) is added to the interface between the a-Si layer (6) and the a-SiC layer (5) to bond both layers to improve electrophotographic properties.
The thickness of this layer is preferably 3 μm or less). In this bonding layer, for example, after forming a thin a-Si layer (6), the content of each of carbon (C) and/or group a elements is gradually increased in the layer thickness direction,
At the end of forming the bonding layer, the content of each a-Si
There is a layer thickness set to achieve the required amount of CM and Group IIIa elements in the C layer (5).

Thus, according to the electrophotographic photoreceptor of the present invention, a-SiF
! (6) and a-3iC layer (5) in combination, carriers are not trapped inside the layers of the photoreceptor, thereby achieving high photosensitivity and a reduction in residual potential, as well as increasing the surface potential. Moreover, since the incident light does not reach the substrate, the photoconductor is suitable for use in semiconductor laser beam printers, which eliminates the need for surface roughening treatment of the substrate.

Next, based on the above results, the present inventors further devoted themselves to research and found that the carbon (C) of the a-5iC layer (5)
) content and I[Group Ia element content were varied in the layer thickness direction, thereby making it possible to obtain photoreceptors with various embodiments.

That is, according to FIGS. 6 to 13, the horizontal axis represents a-SiC
It represents the layer thickness from the interface (a) with the a-SiF of layer (5) to the surface (b) on the opposite side, and the vertical axis represents the C content and I[[group a element content] All amounts are relative amounts. Incidentally, in these figures, the solid line and the broken line indicate the C content and the group (■a) element content, respectively.

As is clear from these figures, in the layer region close to the 5th surface on the incident light side inside the a-3iC layer (5), IIIa
The group element content is relatively low or the C content is relatively high, thereby reducing the 71! fi
The bandgap becomes larger in the Jl region, resulting in higher photoconductivity, and as a result, incident light is photoelectrically converted with high efficiency, and photosensitivity can be increased.

On the other hand, N% close to the a-side! In this region, the content of Group A elements is relatively high or the C content is relatively low, which increases the absorption coefficient in this layer region and allows the incident light to pass through this layer region. completely absorbed.

Therefore, by forming both of the layer regions as described above, it is possible to obtain an electrophotographic photoreceptor having high photosensitivity characteristics and further suppressing the generation of interference fringes.

Also, according to FIGS. 7, 9, 10, and 13, r
The content of group IIIa elements in the fi region is relatively low, and the content of group ll1a elements is relatively high in the Nil region near the a-plane, which makes the Fermi level tilted inside the a-5iC layer (5). , which results in
There are fewer traps for excited carriers under the low electric field region,
As a result, residual potential can be reduced.

Next, a method for manufacturing the electrophotographic photoreceptor of the present invention will be described.

For the a-5i layer (6) and the a-3iCPi (5), a thin film forming method such as a glow discharge decomposition method, an ion blating method, a reactive sputtering method, a vacuum evaporation method, a thermal CVD method, etc. can be used, and The raw material used for this may be solid, liquid, or gas.

In addition, when forming layers other than the a-5i layer (6) and the a-SiC layer (5), these layers may be
-3iC is preferable in that similar thin film forming means can be used, and furthermore, when the same film forming apparatus is used, it is possible to continuously stack layers by a common thin film forming means. There are advantages.

For example, using a glow discharge decomposition device, a-Si layer or a-
When manufacturing a photoreceptor consisting of a 5iC layer, gaseous raw materials include Si-based gases such as SiH4, 5iJ6, and 5iJs, C-based gases such as CHa, Crt, CzHa, CzHb, and CxHs, and He gas + L gas, etc. may be used as a carrier gas.

According to this glow discharge decomposition method, a-
Forming a 5iC layer is desirable in that a significantly high speed of film formation can be achieved.

Next, when the electrophotographic photoreceptor described in the embodiment of the present invention is formed from a-3i or a-5iC using the glow discharge decomposition method, the manufacturing method is performed using the capacitively coupled glow discharge decomposition apparatus shown in FIG. explain.

In the figure, tanks (9) (10) (11) (12)
(13) have SiH4, CzHz, and BzHb (
Hz gas (containing dilution Teo, 2Z), H, and NO gases are sealed, and H2 is also used as a carrier gas.

These gases are controlled by the corresponding regulating valves (14) (15) (
16) (17) It is released by opening (18), and its flow rate is controlled by the mass flow controller (19) (
20) (21) (22) (23), gas from tanks (9), (10), (11), and (12) is sent to the main pipe (24), and NO gas from the tank (13) is sent to the main pipe (25). ). Note that (26) and (27) are stop valves. The gas flowing through the main pipes (24) and (25) is fed into the reaction tube (28);
) is equipped with a capacitively coupled discharge electrode (29), and the high frequency power applied to it is 50W to 3K.
W and a frequency of IMHz to 50 MFIz are appropriate. Inside the reaction tube (28), a cylindrical film-forming substrate (30) made of aluminum is placed on the sample holding table (31). This holding stand (31) is connected to the motor (3
2), and
The substrate (30) is heated to approximately 200 to 400 mL by suitable heating means.
It is heated uniformly to a temperature of 0°C, preferably about 200 to 350°C. Furthermore, inside the reaction tube (28) is a-SiC.
A rotary pump (
33) and a diffusion pump (34).

In the glow discharge decomposition device configured as above,
For example, when forming an a-5iC film containing B on the substrate (32), the regulating valve (14: l (15) (16
) (17) and each 5iHa+CzHz+B
Release zHb+Ht gas. The discharge amount is controlled by mass flow controllers (19), (20), (21), and (22), and these mixed gases are flowed into the reaction tube (28) via the main pipe (24). Then, the reaction tube (28
) is in a vacuum state of about 0.1 to 2.0 Torr,
The substrate temperature is 200 to 400°C, the high frequency power of the capacitively coupled discharge electrode (29) is 5 to 3 W, and the frequency is 1.
In conjunction with the setting of 50MHz to 50MHz, glow discharge occurs, and the gas decomposes and a-SiC containing B.
A film is formed on the substrate at high speed.

(Example) Next, examples of the present invention will be described.

(Example 1) In this example, an a-3i film or an a-5iC film having a single composition was formed over the layer thickness direction, and the spectral sensitivity characteristics were measured.

That is, a 3 x 3 cm square aluminum flat plate was prepared, and an aluminum cylindrical group Fi (3
A part of the circumferential surface of 0) is cut out, and this flat plate is installed in this notch, and an a-5i film or an a-3iC film is produced on this flat plate.

First, add SiH4 gas to 101005e from the tank (9).
H2 gas is supplied from the tank (12) for 300 seconds at a flow rate of
Then, the substrate temperature was set to 300° C., the gas pressure was set to 0.45 Torr, and the high frequency power was set to 150 W, and a 5 μm thick a-Si film was formed on the above flat plate by glow discharge decomposition method. Formed.

In addition, in the above manufacturing method, C from the tank (10) is further added.
2H2 gas is released at a flow rate of 10105e, and B10. Gas was released at a flow rate of 5 sec, and a 5 μm film was deposited on a flat plate under the same manufacturing conditions.
An a-5iC film with a thickness of .

The spectral sensitivity characteristics of the a-5i film and the a-SiC film thus obtained were measured, and the results were as shown in FIG. In the figure, the marks ○ and * are a-Si, respectively.
A plot of the spectral sensitivity of the film and the a-SiC film, a,
b is each spectral sensitivity curve. Note that the measured value of the spectral sensitivity indicates the photoconductivity when equal energy light is irradiated at each wavelength by the comb snow shoveling method.

As is clear from this result, the a-5iC film containing B has lower spectral sensitivity than the a-5i film in the wavelength region of 700 nm or less, but has higher spectral sensitivity than the a-Si film in the wavelength region of 700 nm or more. Sensitivity.

(Example 2) In this example, a carrier injection blocking layer (7) and an a-5i carrier transport layer were formed on a substrate (30) under the manufacturing conditions shown in Table 1 using the glow discharge decomposition apparatus shown in FIG. (6), an a-SiC carrier generation layer (5), and a surface protective layer (8) were sequentially formed to produce an electrophotographic photosensitive drum. Note that NO gas is used to form the carrier injection blocking N(7) and doped with oxygen and nitrogen to improve adhesion to the substrate.

[Margin below]

This drum is attached to a semiconductor laser beam printer (wavelength 7).
70nm, printing speed 20 sheets/min), high-quality images were obtained with high image density, high contrast, and no ghost phenomenon, and also no interference fringes or fog. .

According to Kodama, an a-SiC layer (5) is formed on a glass substrate under the same conditions, and its transmittance (wavelength 7700 m) is
When measured, it was 25χ. Also, this a-S
The B content of the iC layer (5) was about 1100 pp.

(Example 3) In (Example 2), C, Hz gas was further released at a flow rate of 10105e during the formation of the a-St carrier transport layer, and a photoreceptor drum was manufactured under the same manufacturing conditions as in (Example 2) except for the following: As the carrier transport layer of this drum, a-
When forming 5iCN, this photoreceptor drum (Example 2)
When printed using the same laser beam printer, the image density was high and there was no ghosting phenomenon.
Furthermore, although interference fringes did not occur in the image, on the other hand, fogging occurred in the image.

(Example 4) In (Example 2), C
, +1, If a photoreceptor drum is manufactured under the same manufacturing conditions as in Example 2 except that the gas emission is stopped, and an a-5+ layer is formed as the carrier generation layer of this drum, this photoreceptor drum will be When mounted on the same laser beam printer as in Example 2 and printed, no interference fringes were produced in the image, but the image density was low, the contrast was poor, and a ghost phenomenon occurred.

(Example 5) In this example, the carrier injection targeting layer, the a-5i carrier transport layer and the
An electrophotographic photoreceptor as shown in FIG. 3 was manufactured by sequentially forming -5iC carrier generation layers and without forming a surface protective layer.

This photosensitive drum is connected to a semiconductor laser beam printer (
When installed and printed at a wavelength of 770 nm and a printing speed of 20 sheets/min, a high-quality image with high image density, high contrast, and no ghost phenomenon was obtained, with no interference fringes or fog. Ta.

Next, this photosensitive pair was subjected to a polishing and regeneration evaluation test.

That is, the surface of this photoreceptor drum is forcibly polished with diamond powder to a depth of about 0.3 μm and about 0.0 μm from the surface.
The photoreceptor was polished away over a thickness of 7 μm, about 1.2 μm, and about 2.0 μm, and then the photoreceptor was positively charged with +5.6 KV corona discharge, and then irradiated with monochromatic light (770 nm). The saturated surface potential and photosensitivity were measured with The results shown in the table were obtained.

Furthermore, as a comparative example, an a-5i photoreceptor as shown in FIG. 2 was manufactured under the conditions shown in Table 3, and then an evaluation test of polishing and regeneration was performed on this photoreceptor, as shown in Table 2. The results were obtained.

[Margin below]

As is clear from Table 2, the surface potential and sensitivity of the photoreceptor of the present invention do not change significantly from the initial characteristics even after polishing approximately 2.0 μm from the surface, and the image characteristics also maintain the initial good image. was completed.

However, according to the comparative example, the initial characteristics could be maintained until the presence of the surface protective layer (0.3 μm polishing), but the image deteriorated at the edge of the edge after exceeding 0.7 μm. , after polishing by 2.0 μm, the surface potential decreased significantly.

From these experiments, it was confirmed that the photosensitive drum of this example maintains its initial characteristics at least up to a polishing amount of 2.0 μm when re-polishing is performed using the desired polishing means described above.

(Effects of the Invention) As described above, according to the electrophotographic photoreceptor of the present invention, a-3iCN containing group a elements can be used as a carrier generation layer for long-wavelength light, and thereby, semiconductor laser beams This resulted in a photoreceptor suitable for printers. Furthermore, according to this photoreceptor, since the incident light does not reach the substrate, interference fringes do not occur in the image, and there is no need to roughen the surface of the substrate to increase its surface roughness.
This provides a low-cost electrophotographic photoreceptor.

Further, according to the electrophotographic photoreceptor of the present invention, it is possible to prevent photoexcited carriers from being trapped in the layer region of the photoreceptor, thereby achieving high photosensitivity characteristics and a reduction in residual potential, and increasing the surface potential. We were able to.

Furthermore, according to the present invention, the surface layer of the photoreceptor is formed as an a-3iC layer without forming a surface protective layer, and even when using the photoreceptor obtained with this, a clear image with high black background density and no fog can be obtained. Furthermore, since this a-5iC layer is a photoconductive layer, there is no limit to the amount of polishing even if the surface is repeatedly polished and regenerated with an abrasive, thereby maintaining the initial characteristics of the photoreceptor. be able to.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic layer structure of the electrophotographic photoreceptor of the present invention, FIG. 2 is a sectional view showing the layer structure of a conventional general amorphous silicon photoreceptor, and FIGS. Fifth
6, 7, 8, 9, 10, 11, 12, and 13 are cross-sectional views showing other layer structures of the electrophotographic photoreceptor of the present invention, respectively. The figure is a diagram showing the carbon content in the layer thickness direction of the amorphous silicon carbide layer of the electrophotographic photoreceptor according to the present invention and the content of elements in group 1a of the periodic table. Schematic diagram of a capacitively coupled glow discharge decomposition device used in
FIG. 5 is a diagram showing a spectral sensitivity curve of an amorphous silicon carbide layer. l...Conductive substrate 4.8...Surface protection layer 5...Amorphous silicon carbide layer 6...Amorphous silicon layer 7...Carrier injection blocking layer Patent applicant (663) Kyocera Corporation Contaminant Takaoyo Rihito Patent Attorney (889B) Katsuhiko Tahara Figure 1 - Figure 2 Figure 3 Figure 6 Figure 7 a Shi α
Shizuo front (n nail)

Claims (1)

[Claims] At least an amorphous silicon layer on a conductive substrate and 0
．． An electrophotographic photoreceptor characterized in that amorphous silicon carbide layers containing 1 to 10,000 ppm of Group IIIa elements of the periodic table are sequentially laminated, and photocarriers are substantially generated in the amorphous silicon carbide layers.