JPS6270855A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having superior electrostatic chargeability, low residual potential and high sensitivity by providing a laminated structure having an amorphous silicon carbide layer between microcrystalline silicon layers to a photoconductive layer. CONSTITUTION:A blocking layer 3, the 1st photoconductive layer 5, the 2nd photoconductive layer 7 and the 3rd photoconductive layer 9 are successively formed on an Al substrate 1 as an electrically conductive support. The 1st and the 3rd photoconductive layers 5, 9 are made of microcrystalline silicon and the 2nd photoconductive layer 7 is made of amorphous silicon carbide. The resulting electrophotographic sensitive body has superior and stable electrical and optical characteristics, superior electrostatic chargeability, low residual potential and high sensitivity in a wide wavelength region extending to the near infrared region. The adhesion of the layers to the substrate is satisfactory and the sensitive body has superior environmental resistance, is hardly fatigued and also has superior repetitive characteristics.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is used, for example, in an electrophotographic recording device or a copying device, and improves charging characteristics, dark decay characteristics, light sensitivity characteristics, and environmental resistance. The present invention relates to an electrophotographic photoreceptor having excellent performance.

(Prior Art) Conventionally, materials constituting the photoconductive layer of an electrophotographic photoreceptor used in, for example, a Carlson type electrophotographic recording device include CdS, Zno, and Se.

Inorganic materials such as 3e-Te, amorphous silicon, or poly-N-vinylcarbazole (PVCz), t-
Organic materials such as linitrofluorenone (TNF) are mainly known.

(Problems to be Solved by the Invention) However, there are various problems when using these photoconductive materials, and it is necessary to sacrifice some of the characteristics of the device and use these materials depending on the situation. The current situation is that

That is, for example, Se and Cd S are materials that are inherently harmful to the human body, and when manufacturing them, special considerations are required for safety measures, which may complicate the manufacturing equipment. Extra costs are required for its production, and Se and the like also need to be recovered, and these costs are added to the price of the materials. More specifically, for example, Se
(or 5e-Te system) has a low crystallization temperature of 65°C, so crystallization occurs during repeated copying operations.

Practical problems tend to occur due to remaining snow and other problems, and the service life is short.

Furthermore, ZnO has the problem of low reliability because it is easily subject to oxidation-reduction due to its material properties and is extremely susceptible to the influence of the environmental atmosphere.

Furthermore, in organic photoconductive materials, PVCz and TNF
These materials have recently been suspected of being harmful to the human body, and because they are organic materials, they have poor thermal stability and wear resistance, resulting in a short product life.

On the other hand, amorphous silicon (hereinafter abbreviated as a-3i) has attracted attention as a photoelectric conversion material in recent years, and is being actively applied to solar cells, thin film transistors, image sensors, etc.; It is also being studied as a photoconductive material for electrophotographic photoreceptors. This a-8i material has the following advantages which are not found in the other materials mentioned above as a photoreceptor for electrophotography.

(1) It is a non-polluting material and does not require collection treatment.

(2) It has higher spectral sensitivity in the visible light region than conventional materials.

(3) High surface hardness, excellent wear resistance and impact resistance.

As a result, it is a material that is highly anticipated as a photoreceptor for electrophotography. A-8 with such excellent characteristics
i is already being considered as a photoreceptor for Carlson-type electrophotographic recording devices, but the characteristics of the photoreceptor are required to be high resistance and high photosensitivity. Due to its characteristics, it is quite difficult to simultaneously satisfy these requirements with a photoreceptor. For this reason, the characteristics of the electrophotographic recording device described above are obtained using a laminated type a-3i photoreceptor in which a barrier layer is provided between the a-3i photoconductive layer and the support layer, and a surface charge retention layer is further provided on the photoconductive layer. Efforts are being made to satisfy the following.

a-3i is usually formed by a glow discharge decomposition method using cyranos as a raw material;
The electrical and optical properties are greatly influenced by the amount of hydrogen incorporated into the film.

In other words, as more hydrogen is incorporated into the a-8i film, the optical bandgap becomes larger and the resistance becomes higher, but along with this, the photosensitivity to long wavelength light decreases, for example. It becomes difficult to use it in a laser beam printer equipped with a semiconductor laser. Also, a-
When the hydrogen content in the 8i film is high, depending on the film formation conditions, those with bonding structures such as (Si H2)n and Si H2 become dominant in the film, and as a result, the film contains many voids. Since the silicon dangling bonds increase, the photoconductivity deteriorates, making it difficult to use as an electrophotographic photoreceptor.

Conversely, when the amount of hydrogen incorporated into the a-3i film decreases, the optical bandgap becomes smaller and the resistance becomes lower, but the photosensitivity to long wavelength light decreases. However, if the hydrogen content is small, the dangling bonds of silicon are not guaranteed, and the mobility and lifetime of the generated carriers decreases, resulting in poor photoconductivity, making it difficult to use as a photoreceptor for electrophotography. Become something. In addition, as a method to increase the sensitivity to long wavelength light, for example, a film with a narrow optical band gap is formed by mixing cyranos and germane GeH4 and performing glow discharge decomposition. Cyranos and Ge t-1
Since the optimum substrate temperature is different between No. 4 and No. 4, the formed film has many structural defects and good photoconductivity cannot be obtained. Furthermore, G
Since eH4 waste gas becomes toxic when oxidized, there is a problem in that waste gas treatment is also complicated.

This invention was achieved as a result of many experiments in view of the above, and its objectives are to have excellent charging characteristics, low residual potential, and high sensitivity over a wide wavelength range up to the near-infrared region. Another object of the present invention is to provide an electrophotographic photoreceptor that has good adhesion to a substrate and excellent environmental resistance.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, an electrophotographic photoreceptor having a conductive support and a photoconductive layer provided on the conductive support is provided. , the invention has a blocking layer between the conductive support and the photoconductive layer, the photoconductive layer is adjacent to the blocking layer, and has a first photoconductive layer comprising microcrystalline silicon; a second photoconductive layer having amorphous silicon carbide adjacent to the first photoconductive layer on a side opposite to the blocking layer; The gist is that one photoconductive layer has an adjacent side and an adjacent third photoconductive layer having microcrystalline silicon on the opposite side.

(Function) In the electrophotographic photoreceptor according to the present invention, the photoconductive layer formed on the conductive support is improved by having a laminated structure in which amorphous silicon carbide is sandwiched between microcrystalline silicon. There is.

(Example) Hereinafter, the present invention will be described in detail using the drawings.

FIG. 1 is a partial sectional view of an electrophotographic photoreceptor according to an embodiment of the present invention. This electrophotographic photoreceptor has an aluminum base 1 as a conductive support at the bottom layer, and a blocking layer 3, a first photoconductive layer 5, and a second photoconductive layer are formed on the base 1. Layer 7 and third photoconductive layer 9 are formed in sequence.

The base body 1 has a diameter of, for example, 80 m111. Length 350+
It is formed of an aluminum drum of size 111,
The electrophotographic photoreceptor shown in FIG. 1 is formed on the surface of a base 1 made of this drum, and FIG. 1 shows a partial cross section thereof.

In this electrophotographic photoreceptor, the photoconductive layer has first, second, and third photoconductive layers.
The first photoconductive layer 5 and the third photoconductive layer 9 are made of microcrystalline silicon, and the second photoconductive layer 7 is made of amorphous silicon carbide. It is formed of.

As described above, the electrophotographic photoreceptor according to the embodiment of the present invention is
The photoconductive layer is not only made of amorphous silicon as in the prior art, but also contains microcrystalline silicon, which is laminated with amorphous silicon carbide. Microcrystalline silicon is clearly distinguished from amorphous silicon, polycrystalline silicon, etc., and is microcrystalline silicon that is thought to be formed by aggregation of microcrystals with a grain size of about several tens of angstroms or more. In other words, when performing X-ray diffraction measurements, since amorphous silicon is amorphous, only a halo appears and no diffraction pattern can be observed, but microcrystalline silicon has a crystalline diffraction pattern around 27° to 28°. show. Also,
The dark resistance of polycrystalline silicon is 10θΩ・Cl1l
microcrystalline silicon is 10Ω·01 or more.

To form an electrophotographic photoreceptor made of microcrystalline silicon, as in the case of forming an electrophotographic photoreceptor made of amorphous silicon, silane gas is used as a raw material gas, and the support is decomposed by high-frequency glow discharge decomposition. It is formed by depositing microcrystalline silicon on top, but it is easier to form by setting the temperature of the support higher and increasing the high frequency power than when forming amorphous silicon. In this way, by raising the temperature of the support and increasing the high-frequency power, it is possible to increase the flow rate of the raw material gas such as cyrano, and as a result, the speed at which a microcrystalline silicon film is formed can be increased. . In addition, S of the raw material gas
! When a gas diluted with hydrogen is used, including a higher order silano gas such as H4 or Si2H6, microcrystalline silicon is particularly easily formed effectively.

In addition, the present electrophotographic photoreceptor is safe because it can be manufactured using closed system manufacturing equipment, similar to those using conventional amorphous silicon, and the product is harmless to the human body. Additionally, it has excellent heat resistance, moisture resistance, and abrasion resistance, so it does not deteriorate even after long-term use and has a long lifespan. Furthermore, since a gas for increasing or decreasing long wavelengths such as Qe 84 is not required, there is no need for extra waste gas treatment equipment, and there is an advantage that industrial productivity is extremely high.

Furthermore, the microcrystalline silicon that forms the photoconductive layer contains hydrogen at 0.1 to 30 atomic percent, resulting in a harmonious ratio of dark resistance to bright resistance, resulting in excellent photoconductive properties. .

The optical energy gap (E 2 ) of microcrystalline silicon is smaller than that of amorphous silicon, which is 1.65 to 1.70 eV. Furthermore, the optical energy gap of microcrystalline silicon depends on the grain size and crystallinity of the microcrystalline silicon microcrystal grains contained therein. Since the optical energy gap (E) of crystalline silicon is as small as 1.10 V, the optical energy gap of microcrystalline silicon decreases as the microcrystallinity of microcrystalline silicon increases.

In recent years, printers using semiconductor lasers as light sources have been actively developed, and some of them use amorphous silicon photoreceptors. However, since the wavelength of semiconductor laser light is 790 nm, which is longer than the high-sensitivity region of amorphous silicon, when an amorphous silicon photoreceptor is used, a laser intensity exceeding the capability of the semiconductor laser is required, which poses a problem in use.

Microcrystalline silicon has a smaller optical energy gap (E) than amorphous silicon,
The high sensitivity range extends to the near infrared range, and it has very good characteristics as a photoreceptor for semiconductor laser printers.

As mentioned above, the photoconductive properties can be improved by incorporating hydrogen into microcrystalline silicon, but in order to dope hydrogen into the microcrystalline silicon layer for this purpose, for example, when doping is carried out by a glow discharge decomposition method, Glow discharge is performed by introducing cyranos such as SiH4 and 3i2He as a raw material gas and hydrogen or the like as a carrier gas into the reaction chamber. Also, as another method, 5iF
A mixed gas of silicon halide and hydrogen such as s or 3i 014 may be used as the raw material gas, or microcrystalline silicon containing hydrogen may be obtained by reacting in a mixed gas system of cyranos and silicon halide. be able to. Furthermore, it can also be formed by a physical method such as sputtering, without relying on the glow discharge decomposition method. The film thickness of the photoconductive layer containing microcrystalline silicon in this electrophotographic photoreceptor is 1-8.
It is preferably 0 μm, more preferably 5-50 μI.

In addition, as an impurity element to be doped into microcrystalline silicon, in order to make it p-type, it is necessary to
Group elements such as B, AI, Ga.

In, Ti, etc. are preferred. To make it n-type, use elements from group V of the periodic table, such as N, P, AS, and Sb.

Bi and the like are preferred. Doping with these n-type impurities or n-type impurities is used to prevent charges from being injected from the support into the photoconductive layer, to improve photosensitivity characteristics, or to make the layer i-type and increase its resistance. This is done for the following purposes.

Furthermore, it is desirable to dope the microcrystalline silicon with at least one of nitrogen, carbon, and oxygen in order to increase its dark resistance and enhance its photoconductive properties. It is thought that these elements precipitate at the grain boundaries of microcrystalline silicon and act as terminators of dangling bonds of silicon, reducing the density of states existing in the forbidden band between bands, and producing the above effect. .

Since microcrystalline silicon has a relatively large refractive index of 3 to 4, light reflection easily occurs on the surface.

Therefore, the proportion of light absorbed by the photoconductive layer decreases,
Since light loss increases, it is preferable to provide an anti-reflection device on the surface. Further, it is desirable to provide a surface protective layer to protect the light guiding N layer. As a material for such a surface protective layer, 513N4. Sl○2, SiC,
AI203, a-8in; H, a-8i O:
There are inorganic compounds such as H, a -8i C:), and organic materials such as polyvinyl chloride and polyamide.

FIG. 2 is a partially enlarged sectional view of an electrophotographic photoreceptor according to another embodiment of the present invention. layer 1
1, and the other configurations are the same as the electrophotographic photoreceptor shown in FIG. This surface protective layer 11 is made of amorphous silicon carbide formed to a thickness of 2 μm.

As mentioned above, in order to have excellent photoconductive properties, the first photoconductive layer 5 and the third photoconductive layer 9 of the electrophotographic photoreceptor shown in FIGS. 1 and 2 are configured. Microcrystalline silicon contains hydrogen (μc-3
i:H), and the amorphous silicon carbide constituting the second photoconductive M7 contains hydrogen and is
i C:H).

Furthermore, it is preferable that such hydrogen-containing amorphous silicon carbide and microcrystalline silicon be doped with either one of Group I or Group V elements of the periodic table as described above.

In addition, in order to improve the charging ability and charge retention ability of the electrophotographic photoreceptor, carbon is added to the microcrystalline silicon.
It is preferable to contain at least one of nitrogen and oxygen. First, second and third photoconductive layers 5.7
．． One of the important functions of 9 is the generation of charge, and the optical energy gap (E') of the microcrystalline silicon of the first photoconductive layer 5 and the third photoconductive layer 9
Because it has a smaller optical energy gap than amorphous silicon, it has the ability to absorb nearer infrared light and generate charges, making it suitable for photoreceptors for printers using semiconductor lasers.

In the electrophotographic photoreceptor shown in FIGS. 1 and 2, a blocking layer 3 is provided between the substrate 1 and the photoconductive layers 5 to 9.
, that is, a barrier layer is provided, which is similar to the substrate 1
This is provided to prevent injection of electrons or holes from.

More specifically, when positively charging the surface of a photoreceptor using the Carlson method, for example, the blocking layer 3 is formed as a p-type layer to prevent injection of electrons from the substrate 1 side, and the blocking layer 3 is formed as a p-type layer on the surface of the photoreceptor. When negative charging is performed, blocking 3 is formed as an n-type to prevent injection of holes from the base 1 side. In addition to the above, it is basically possible to provide an insulating film as a blocking layer and charge the photoreceptor positively or negatively. In any case, a microcrystalline silicon type material is used for part or all of the photoconductive layer, and the substrate 1 is
By providing the blocking layer 3 between the photoreceptor and the electrophotographic photoreceptor, it is possible to construct an electrophotographic photoreceptor that has excellent charge retention ability, good photoconductivity, and remarkable performance in optical fatigue characteristics, cycling characteristics, and the like. Further, the thickness of the blocking layer H3 is preferably in the range of 100 Å to 10 μm, and the blocking layer 3 may be formed of amorphous silicon or microcrystalline silicon.

FIG. 3 is a schematic diagram of a film forming apparatus for manufacturing the electrophotographic photoreceptor of the present invention. In the same figure, 13.15.17
．． Reference numeral 19 indicates reaction gas cylinders, and each cylinder contains, for example, Si H4, 82Ha, CH4, etc. as source gas. 21, 23, 25, 27 are gas pressure regulators, valves 29.31, 33.3 respectively.
5 allows the flow rate to be set. 37 is a gas mixer, and the reaction gases are sufficiently mixed within this mixer. Three are reaction containers, and a drum base 41 constituting the support base of the electrophotographic photoreceptor of the present invention is housed in this and placed on a support base 45 . 43 is a cylindrical electrode, and this cylindrical electrode 43 is connected to the high frequency power source 5.
7 is connected. Further, a heating heater 51 is provided inside the drum base 41 so that the drum base 41 can be heated. Drum base 41
The support table 45 on which the
It is connected to and is designed to be rotationally driven.

Reference numeral 55 denotes an exhaust gate valve, and the inside of the reaction vessel 39 is connected to an exhaust system (not shown) through this exhaust gate valve 55, so as to form a vacuum necessary for generating glow discharge inside the reaction vessel 39. It has become. The drum base 41 is made of aluminum, for example, and has a diameter of 8 Q mm and a length of 350111 m.

Next, a method of manufacturing the electrophotographic photoreceptor shown in FIGS. 1 and 2 using this apparatus by a glow discharge method will be described.

First, the drum base 41 is degreased with trichloride and placed on the support stand 45 inside the reaction vessel 39 .

In this case, the drum base 4 may be
The surface of 1 is subjected to acid treatment, alkali treatment, sandblasting, etc. Next, the inside of the reaction vessel 39 is evacuated through the exhaust gate valve 55 and set to a degree of vacuum of about 0°11” or less, for example, 10-5 Torr.Then, the drum base 41 is uniformly heated by the heater 51. After the temperature of the drum base 41 is maintained at 300°C, the exhaust gate valve 55 is closed, and the valve 21 of the cylinder 13 filled with S!H4 is opened to discharge S!H4 at a flow rate of 5008 CCM.
iH4 is introduced into reaction vessel 39. At this time, the drum base 41 is being rotated by the motor 49 at a speed of 10 revolutions per minute. Next, B2 H8 was added from cylinders 15 and 17 in the same manner.

CH4 to B2 H8/Si H4=10-3.1008
A ratio of 0 CM is introduced into three reaction vessels. Then, the reaction vessel 39 is pumped by a mechanical booster pump, rotary pump, etc. (not shown) via an exhaust gate valve 55.
Evacuate the inside and reduce the internal pressure to 1 Torr 1. :adjust.

Next, the frequency is 13.56 MHz by the high frequency power supply 57.
300W of power was supplied to the cylindrical electrode 43, and the SiH
4, B2 H8, Cl-14 plasma is generated to form p-type amorphous silicon carbide as the blocking layer 3 on the drum base 41, that is, on the base 1 shown in FIGS. 1 and 2.

Next, squeeze the valve 29.31 of the cylinder 13.15, and
iH4 200 S CCM, B 2 Ha /
Adjust the SiH4 to 10-7, close the valve 33 for SiH4, open the pressure reducing valve 27 of the cylinder 19 filled with H2, and use the valve 35 to pump H2 at a flow rate of 28LM.
2 is introduced into the reaction vessel 39. Then, the reaction pressure was increased to 1.
After adjusting to 2 Torr, 2 kW of power is supplied from the high frequency N source 57 to form a 25 μm microcrystalline silicon layer as the first photoconductive layer 5 on the blocking layer 3 .

Subsequently, Si was applied at a flow rate of 500 SCCM by valve 29.
H4 is introduced into the reaction vessel 39, and further B2Ha/Si
CH at a flow rate of 1008CCM after setting H4 to 10-6
4 is introduced into the reaction vessel 39. Then, after adjusting the reaction pressure to 1°0 Torr, the high frequency power supply 57
A power of 00 W is supplied to form an amorphous silicon carbide layer of 5 μm as a second photoconductive layer 7 on the first photoconductive layer 5 .

Next, as in the case of forming the first photoconductive layer 5, a third photoconductive layer 9 is formed on the second photoconductive layer 7.
A microcrystalline silicon layer of μm is formed.

The electrophotographic photoreceptor shown in FIG. 1 is formed through the above manufacturing process, and a second photoreceptor is formed by further forming a 2 μm thick amorphous silicon carbide on the third photoconductive layer 9 as a surface image: flW111. The electrophotographic photoreceptor shown in the figure is thus formed.

When the drum of the electrophotographic photoreceptor formed as described above was incorporated into a semiconductor laser printer and image formation was performed using the Carlson method, the exposure tube on the surface of the photoreceptor was 25 e.
Clear and high-resolution images could be obtained even at ra/cm2. Furthermore, when copying was repeated to examine the reproducibility and stability of this transfer process, the transferred images were extremely good. It has also been demonstrated that it has excellent durability such as abrasion resistance.

In the above embodiments, the electrophotographic photoreceptor has a support base 1, a blocking M3, a light mW layer 5, 7, and a surface protection layer 11, but in addition to these, a support base and a charge transport layer are also provided. , a charge generating layer or a supporting substrate, a blocking layer, a charge transport layer, a charge generating layer. Part or all of the charge generation layer is formed from microcrystalline silicon, and the thickness of the charge generation layer in this case may be as thin as 0.1 to 10 μm.
is preferred. The charge transport layer allows carriers generated in the charge generation layer to efficiently reach the expected support side, thereby forming a layer with a long carrier life and high mobility, improving carrier transportability. The charge transport layer may be formed of amorphous silicon or microcrystalline silicon, and in order to increase the dark resistance and improve the charging ability, the charge transport layer may be formed of an element from Group I or V of the periodic table. It is preferable that either one of them be lightly doped, that is, doped at a low concentration.

Furthermore, in order to improve charging ability and provide both charge transport and potential retention, it is also possible to contain at least one of carbon, nitrogen, and oxygen. Furthermore, if the thickness of the charge transport layer is too thin, it will not perform its function satisfactorily, and the preferred thickness is 3 to 80 um.
It is. In addition, the blocking layer is formed on the supporting substrate in order to improve the charge retention ability of a photoreceptor in which the functions of the charge transport layer and the charge generation layer are separated. It is necessary to use the mold layer appropriately depending on the charging characteristics. Furthermore, this blocking layer may be formed of amorphous silicon as described above, or may be formed of microcrystalline silicon.

[Effects of the Invention] As explained above, according to the present invention, the photoconductive layer formed by laminating microcrystalline silicon and amorphous silicon carbide has excellent and stable electrical and optical properties. It has excellent charging properties, low residual potential, high sensitivity over a wide wavelength range up to the near-infrared region, good adhesion to the substrate, excellent environmental resistance, low fatigue, and excellent repeatability. Are better.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged sectional view of an electrophotographic photoreceptor showing one embodiment of the present invention, FIG. 2 is a partially enlarged sectional view of an electrophotographic photoreceptor showing another embodiment of the invention, and FIG. 2 is a configuration diagram of a film forming apparatus for manufacturing the electrophotographic photoreceptor shown in FIGS. 1 and 2. FIG.

Claims (15)

[Claims] (1) An electrophotographic photoreceptor having a conductive support and a photoconductive layer provided on the conductive support, comprising a blocking layer between the conductive support and the photoconductive layer; The photoconductive layer is adjacent to the blocking layer and is adjacent to a first photoconductive layer having microcrystalline silicon on a side opposite to the side where the blocking layer is adjacent to the first photoconductive layer. , a second photoconductive layer comprising amorphous silicon carbide; and a third photoconductive layer adjacent to the second photoconductive layer on a side opposite to the side adjacent to the first photoconductive layer and comprising microcrystalline silicon. An electrophotographic photoreceptor comprising a photoconductive layer. (2) The electrophotographic photoreceptor according to claim 1, wherein the microcrystalline silicon contains hydrogen atoms. (3) The microcrystalline silicon is listed in the periodic table.
The electrophotographic photoreceptor according to any one of claims 1 to 2, characterized in that it contains a group III element. (4) The electrophotographic photoreceptor according to any one of claims 1 to 2, wherein the microcrystalline silicon contains an element of group V of the periodic table. (5) The electrophotographic photoreceptor according to any one of claims 1 to 4, wherein the microcrystalline silicon contains at least one of carbon, oxygen, and nitrogen. (6) The electrophotographic photoreceptor according to claim 1, wherein the amorphous silicon carbide contains hydrogen atoms. (7) The amorphous silicon carbide is found in III of the periodic table.
7. The electrophotographic photoreceptor according to claim 1 or 6, characterized in that it contains an element of the above group. (8) Claim 1, wherein the amorphous silicon carbide contains an element of Group V of the periodic table.
6. The electrophotographic photoreceptor according to item 6. (9) The electrophotographic photoreceptor according to claim 1, wherein the blocking layer is made of microcrystalline silicon containing at least one element among carbon, oxygen, and nitrogen. . (10) Claim 1, wherein the blocking layer is made of amorphous silicon.
The electrophotographic photoreceptor described in Section 1. (11) The electrophotographic photoreceptor according to claim 1, wherein the blocking layer is made of amorphous silicon carbide. (12) The electrophotographic photoreceptor according to claim 1, wherein the blocking layer is made of amorphous silicon nitride. (13) Claims 9 to 1, wherein the blocking layer contains at least one element from either Group III or Group V of the periodic table.
The electrophotographic photoreceptor according to any one of Item 2. (14) The blocking layer simultaneously contains at least one element from Group III and Group V of the periodic table, respectively, according to any one of claims 9 to 12. photoreceptor for electrophotography. (15) Claim 1, wherein the photoconductive layer has a protective layer adjacent to the third photoconductive layer on a side opposite to the side adjacent to the second photoconductive layer. to 14th
3. The electrophotographic photoreceptor according to any one of the items.