JPS6161388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic image forming member, particularly an electrophotographic image forming member in which a photoconductive layer is composed of an amorphous semiconductor based on silicon (hereinafter referred to as an a-Si semiconductor). This is related to the improvement of.

In addition to being amorphous, a-Si semiconductors exhibit excellent photoconductive properties, are essentially non-polluting, the Si material itself can be obtained at a relatively low cost, and it is possible to dope with impurities. Since layers controlled to be p-type or n-type can be easily obtained, a wide range of applications as semiconductor devices can be considered. Among them, application to the photoconductive layer of an electrophotographic image forming member as disclosed in JP-A-54-78135 is particularly promising.

As shown in the above-mentioned Japanese Patent Application Laid-Open No. 54-78135, a-Si semiconductors exhibit a wide range of physical properties such as dark resistance, bright resistance, and photoconductive properties, depending on the manufacturing conditions. In order to match the characteristics required for the photoconductive layer of an electrophotographic image forming member, various improvements must be made including reproducibility and productivity. In particular, considering that conventional a-Si semiconductors have been developed for application to so-called solar cells as shown in USP 4064521, research and development will be renewed from the viewpoint of electrophotography. There is plenty of room for improvement, and if mass productability is taken into account, electrophotographic photoconductive layers made of a-Si semiconductors still need to be improved to meet the optimum design requirements.

The present invention is based on such a viewpoint,
The object thereof is to improve an electrophotographic image forming member having a photoconductive layer composed of an amorphous semiconductor (a-Si semiconductor) based on silicon and containing hydrogen and/or halogen atoms.

Another object of the present invention is to provide an electrophotographic imaging member having a photoconductive layer comprised of an a-Si semiconductor that satisfies optimal design requirements for electrophotography.

Another objective is to provide an electrophotographic image forming member that is excellent in reproducibility, productivity, and mass productability.

The electrophotographic image forming member of the present invention is an electrophotographic image forming member having a support and a photoconductive layer, wherein the photoconductive layer contains hydrogen atoms and/or halogen atoms based on silicon atoms. It is composed of an amorphous semiconductor and has a refractive index n of 2.5 or more.
3.5 or less and a layer thickness of 5μ or more, a filling degree of 2.15g/ ^cm3 or more and a layer thickness of 2000Å~
It is characterized by being formed by laminating layer regions having a thickness of 5μ. By configuring the photoconductive layer in this manner, the above-mentioned objects can be effectively achieved, and an electrophotographic image forming member having excellent electrophotographic properties can be obtained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrophotographic image forming member of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view schematically showing the layer structure of a preferred embodiment of the electrophotographic image forming member of the present invention.

Electrophotographic imaging member 100 shown in FIG.
A photoconductive layer 102 made of an a-Si semiconductor on a support 101 has a refractive index n from the support 101 side.
is 2.5 or more and 3.5 or less and the filling degree is
It has a layer area 104 of 2.15 g/cm ³ or more, and these layer areas are formed in a laminated state.

The imaging member 100 shown in FIG. 1 has a free surface 105 in the layer region 104 on which a so-called electrophotographic imaging process is applied to form, for example, a visible image, such as a sheet of paper or the like. This visible image is transferred and fixed onto a transfer member to provide a copy.

The layer region 104 is a region that is sensitive to the irradiated light and generates photocarriers when a photoimage is irradiated in the electrostatic image forming process, and has excellent photosensitivity and effective generation of photocarriers. As a result of extensive research and study by the present inventors, this is achieved by a layer formed under layer forming conditions such that the degree of filling is 2.15 g/cm ³ or more, as described above.

The layer region 103 has the function of transporting the carrier generated in the layer region 104, and in order to effectively transport the carrier, it is designed so that its refractive index n is 2.5 or more and 3.5 or less. given by the created layer.

In the present invention, the photoconductive layer 102 is constructed by laminating the layer region 103 and the layer region 104 that exhibit the physical properties that give the above-mentioned numerical values. The object of the invention is effectively achieved.

In the present invention, the layer 103 has a refractive index n of 2.5 or more and 3.5 or less, but a layer having a refractive index in such a range is formed at a much higher layer formation rate than in the conventional case. photoconductive layer 1
02 production time can be dramatically shortened, and productivity can be significantly increased. This means that when the photoconductive layer requires a layer thickness of more than 10 meters or more, such as an image forming member applied to the Carlson process, the comparative layer thickness may be reduced, such as the photoconductive layer when a conventional development process is applied. This is extremely advantageous when required.

This point can be cited as a very remarkable effect when considering that the layer formation speed of the a-Si semiconductor itself, which has been considered useful in the past, is much lower than that of, for example, Se. The layer region 103 provides the layer thickness required for the photoconductive layer of conventional electrophotographic imaging members, and that layer thickness can be obtained in a short period of time. Therefore, it is extremely superior in terms of productivity and mass production.

Examples of the halogen atoms contained in the a-Si semiconductor constituting the photoconductive layer 102 include elements of the so-called halogen group, and F, Br, etc. are particularly preferred and are employed in the present invention. be done. The amount of hydrogen and/or halogen atoms contained in the photoconductive layer 102 influences its electrical or photoconductive properties, and is appropriately determined to obtain desired properties.

In the present invention, layer region 103 and layer region 10
4, the amount range differs depending on the characteristics required for each layer region.

In the present invention, in the layer region 103, the amount of hydrogen and/or halogen atoms contained is usually 1 to 1.
40 atomic%, preferably 5 to 30 atomic%,
In the layer region 104, the amount is usually 5 to 5.
It is set to 40 atomic%, preferably 15 to 30 atomic%.

The layer thickness of the photoconductive layer 102 in the present invention is appropriately determined as desired depending on the electrophotographic properties of the photoconductive layer to be formed, particularly the photoconductive properties and the electrophotographic process to be applied.

In the present invention, the layer thickness of the photoconductive layer 102 is
Usually 5-80μ, preferably 10-70μ, optimally
It is desirable that the thickness be 10 to 50μ. The reason why the layer thickness of the photoconductive layer is selected in such a numerical range is due to the above-mentioned requirements, but if it is thicker than the above-mentioned numerical range, it is also due to the adhesion with the first support. These problems include: lack of quality, poor resistance to repeated thermal or mechanical action, and reduced production efficiency.Secondly, the layer formation conditions must be adjusted so that the desired properties are uniform in the thickness direction of the layer. For example, it becomes difficult to control. Photoconductive layer 1
If the layer thickness of 02 is smaller than the above value,
The potential contrast of the electrostatic image formed is low,
In addition to difficulty in development, the development speed must be reduced, and photoconductive properties sufficient for electrophotography cannot be obtained.

In the present invention, the layer thickness of the photoconductive layer 102 is
Although the thickness of the layer region 103 and the layer region 104 constituting the layer 102 can be selected and determined from the ranges described above, the present invention will be more effective if the layer thicknesses are selected and determined from the following ranges. can achieve the purpose of That is, the layer thickness of the layer region 103 is desirably set to 5μ or more, and the layer region 104
The layer thickness is desirably 2000 Å to 5 μm.

Layer regions 103 and 10 constituting the photoconductive layer 102
4 can be controlled to be p-type, i-type, or n-type by doping with n-type impurities, p-type impurities, or both impurities during the layer formation process.

The impurities doped into the layer region 103 or 104 include elements of group A of the periodic table, such as B, Al, Ga, In, and Te, to make the layer region 103 or 104 p-type.
etc. are mentioned as suitable ones, and in case of n-type, elements of group A of the periodic table, such as N, P,
Preferred examples include As, Sb, Bi, and the like.

The amount of impurity doped into the layer region 103 or 104 is determined appropriately depending on the desired electrical and optical characteristics, but in the case of p-type impurity, it is usually
10 ^-6 to 10 ^-3 atomic%, preferably 10 ^-5 to 10 ^-4 atomic
%, in the case of n-type impurities, usually 10 ^-8 ~
It is desirable that it be 10 ^-3 atomic%, preferably 10 ^-8 to ^{10 -4} atomic%.

The photoconductive layer 102 in the present invention can be formed using a glow discharge method (abbreviated as GD method), a sputtering method (abbreviated as SP method), an ion plating method (abbreviated as IP method), or an electron beam method (abbreviated as IP method). E.B.
(abbreviated as law) etc. Furthermore,
Instead of forming the entire photoconductive layer 102 using the same layer forming method, each layer region may be formed by selecting an appropriate method to obtain the characteristics required for each layer region. In the present invention, the photoconductive layer 102 is formed by the layer forming method described above, but in particular, the layer region 103 is formed by the DG method or the EB method, and the layer region 104 is formed by the DG method or the EB method.
Formation by the GD method is preferable because it provides desirable results.

An imaging member 100, such as the electrophotographic imaging member shown in FIG. In this case, it is preferable to provide a barrier layer between the photoconductive layer 102 and the support 101, which functions to prevent injection of carrier from the support 101 side during charging processing during electrostatic image formation. This is even more preferable. Such a support 10
The material forming the barrier layer that has the function of blocking carrier injection from the first side is appropriately selected depending on the type of support selected and the electrical characteristics of the photoconductive layer to be formed. is used. Examples of such barrier layer forming materials include:
Inorganic insulating compounds such as Al ₂ O ₃ , SiO, SiO ₂ , organic insulating compounds such as polyethylene, polycarbolite, polyurethane, parylene, Au, Ir, Pt,
Metals such as Rh, Pd, and Mo.

The support 2 may be electrically conductive or electrically insulating. As the photoconductive support, for example,
Stainless steel, Al, Cr, Mo, Au, Ir, Nb, Te,
Examples include metals such as V, Ti, Pt, and Pd, and alloys thereof. As the electrically insulating support, films or sheets of synthetic resins such as polyester, polyethylene, polycarbonate, cellulose triacetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, glass, ceramic, paper, etc. are usually used. . It is desirable that at least one surface of these electrically insulating supports is electrically conductive treated.

For example, if it is glass, its surface is conductive treated with In ₂ O ₃ or SnO ₂ , or if it is a synthetic resin film such as polyester film, it is treated with Al, Ag,
Pb, Zn, Ni, Au, Cr, Mo, Ir, Nb, Ta, V,
Vacuum evaporation, electron beam evaporation with metals such as Ti and Pt,
The surface is made conductive by sputtering or by laminating with the metal. The shape of the support may be any shape, such as a cylinder, a belt, or a plate, and the shape is determined depending on the need. In the case of continuous high-speed copying, an endless belt or a cylindrical shape is used. It is desirable to do so. The thickness of the support is determined appropriately so that the desired image forming member is formed, but when flexibility is required as an image forming member, the support function can be fully demonstrated. Within this range, it is made as thin as possible. However, in such cases, from the viewpoint of manufacturing and handling of the support, mechanical strength, etc., it is usually 10μ.
This is considered to be the above.

FIG. 2 shows an example of a suitable apparatus for forming the photoconductive layer of the electrophotographic imaging member of the present invention, particularly layer region 103 shown in FIG.

On the base plate 201, there is an exhaust port 2 at the top.
A gas introduction pipe 205 for introducing gas into a deposition chamber 204 in which a glass bell jar 203 having 0.02 is installed and which can reduce the pressure, and a silicon evaporator 20
An electron gun 208 for irradiating an electron beam onto a silicon evaporator 206 housed in a crucible 207 containing 6, and a shutter 209 that moves to prevent silicon from evaporating to the upper part are installed.

The gas introduction pipe 205 supplies a high frequency electric field to the deposition chamber 20.
The high-frequency coil 210 to be formed in the high-frequency coil 210 has a structure in which the tip thereof is ring-shaped and provided with a large number of pores so that gas can be uniformly introduced around the central axis of the high-frequency coil 210. The shutter 209 has a structure that can rotate as shown by arrow A so as to prevent silicon from flowing out of the crucible unless necessary.
A support 211 for forming a photoconductive layer is placed above the high-frequency coil 210, and a radiation heating device 212 is placed on the back side of the support 211 for heating the support 211 to a desired temperature. .

In the figure, two supports are provided, and the two supports 211-1 and 211-2 are arranged so that a layer can be uniformly formed with a uniform thickness over the entire layer forming surface. It is installed slantingly in an umbrella shape, and the arrow B
As shown, two supports 211-1, 211-2
It is designed so that it can be rotated around the center.

The high frequency coil 210 includes a base plate 20
1, high frequency power can be applied from an external high frequency power source 213, and an electric field is formed at a predetermined frequency.

A DC power source 214 is connected to the radiation heating device 212 .

Next, an example of forming the layer region 103 in the image forming member of the present invention using the apparatus shown in FIG. 2 will be described in detail.

A silicon evaporator 206 having a predetermined purity is placed in a crucible 207, and a predetermined cleaning treatment is performed.
The heating device 2
It is installed in the front of the high frequency coil 210 so as to form a roof shape, and rotates around the central axis of the high frequency coil 210.

After the preparations have been made in this way, the deposition chamber 2
Exhaust the inside of 04 and adjust the base pressure to about 1×10 ^-6 Torr.

After the degree of vacuum in the deposition chamber 204 reaches a predetermined value, a gas that can introduce hydrogen into the layer that can be formed, usually with a purity of 99.999% or more, is introduced through the fine holes of the stainless steel gas introduction tube 205. _O2
H ₂ containing 0.5 to 10% is introduced into the deposition chamber 204 so that the degree of vacuum is approximately 1×10 ⁻³ Torr.

The degree of vacuum in this case is not limited to the above value, and in normal cases, the degree of vacuum is 3×10 ^-3 to 5×
Supposed to be in the range of 10 ^-5 Torr.

In addition to H ₂ , the gas introduced into the deposition chamber 204 may be, for example, silane gas such as SiH ₄ or Si ₂ H ₆ , a mixed gas of H _{2 and silane gas, or diluted gases such as H 2} and silane gas. If used, Ar, He
You may use a mixture of inert gases such as.

Separately, in the region where impurities are doped into the formed a-si:H layer to control it to p-type or n-type,
It is also possible to mix doping gases such as PH ₂ and B ₂ H ₆ in a predetermined ratio and introduce the mixture into the deposition chamber 204 .

The high frequency power supply 213 is turned on and high frequency power is applied to the high frequency coil 210. Next, gas for hydrogen introduction is introduced into the deposition chamber 20 through the gas introduction pipe 205.
When the gas is introduced into the deposition chamber 204 at a pressure of 0.1 to 1 Torr, the introduced gas is activated in a spatial region within the deposition chamber 204 that includes the high frequency coil 210, thereby forming an active atmosphere. Subsequently, the hydrogen gas pressure is adjusted to the desired value.

The active atmosphere is created by the fact that the gas introduced into the deposition chamber 204 exhibits discharge development under the action of an electric field, and as a result, the gas molecules are ionized, radicalized, excited, or turned into plasma. It is formed.

With the active atmosphere formed in the deposition chamber 204 as described above, the electron gun 20
8 to irradiate the silicon evaporator 206 with an electron beam.

The silicon evaporator 208 is heated by the electron beam irradiation, and as a result, the silicon evaporates and flies above the deposition chamber 204. On the way, as it passes through the active atmosphere, activated gas is released. It collides with particles and causes a reaction.

Silicon particles that have passed through the active atmosphere are
Two supports 211-1, 211 rotating at a constant speed
-2, an a-Si:H layer is deposited on the surface of the support 21
1-1 and 211-2 with a uniform thickness over the entire predetermined area.

The supports 211-1 and 211-2 are the heating device 2
12, the support is heated to a predetermined support temperature (Ts) before layer formation, and during layer formation, it may be maintained at a predetermined temperature or an appropriate temperature change may be applied. These are selected according to the layer forming conditions to obtain the characteristics required for the layer to be formed. However, when the deposition rate exceeds 10 Å/sec, a temperature of 200°C or higher is required.

A of a predetermined thickness is placed on the supports 211-1 and 211-2.
- At the stage when the Si:H layer is formed, the operation of the electron gun 208 is stopped and the shutter 209 is rotated to cover the crucible 207, and then gas introduction and power input to the high frequency coil 210 are stopped, Finish layering.

During layer formation, the output (power) of the electron gun 208 for irradiating and heating the silicon evaporator 206 is determined as appropriate to obtain a desired deposition rate.

It has been confirmed that the power input to the high-frequency coil 210 has a large effect on the characteristics and deposition rate of the formed layer, similar to the GD method and the SP method.

In order to achieve the purpose of the present invention,
It is usually 10W to 500W, preferably 50W to 200W, and the frequency is RF (radio
frequency) region is adopted, and in the normal case
It is considered to be 0.1MHz to 100MHz.

FIG. 3 is a schematic explanatory diagram showing another suitable apparatus for forming a photoconductive layer in the present invention.

Inside the deposition chamber 301, a cathode electrode 302 and an anode electrode 303 to which high frequency power is introduced by a high frequency power source 308 are installed at an interval of about 50 mm. A conductive support 3 is placed on the anode electrode 303.
05 is placed, and the temperature of the support is freely controlled by a heater 304. The deposition chamber 301 is
The air is evacuated by opening the valve 306 leading to the rotary pump, and then evacuated to a vacuum level of ~1×10 ^-6 Torr or more by opening the main valve 307 leading to the diffusion pump. The reaction gas mainly composed of silane is supplied through the gas introduction valve 3.
09 and 310 control the gas flow rate to a desired value, and main valve 307 controls the gas pressure in the deposition chamber 301.

Next, the case where the layer region 103 is formed by the GD method using the apparatus shown in FIG. 3 will be described in detail.

First, the inside of the deposition chamber 301 is evacuated and 1×
10 ^-6 Torr Open the gas inlet valve 309 to check the purity.
99.999% silane gas is introduced at a flow rate of 80SCCM, and at the same time _O2 gas with a purity of 99.999% is introduced through valve 31.
0 and introduce at a flow rate of 0.1 to 5 SCCM. The main valve 307 is controlled to set the degree of vacuum in the deposition chamber 301 to 0.1 to Torr. Next, a high frequency power source 308 generates plasma between the cathode electrode 302 and the anode electrode 303 with an introduced power of 150 W, and a
-Si: forms H layer.

The above conditions for deposition are just an example, and it is also possible to use a mixed gas of H ₂ , Ar, or He in addition to SiH ₄ as the reaction gas.
In order to control the p-type or n-type by doping the width of the Si:H layer with impurities, a predetermined amount of impurity doping gas such as PH ₃ or B ₂ H ₆ can be introduced.

The tendency to increase the deposition rate is due to
This roughly matches the increasing trend of SiH ₄ proportion, fluororate, and high frequency power.

The gas pressure inside the deposition chamber 301 is 0.05~
Can be changed within a range of 1Torr.

The layer region 104 formed on the layer region 103 is
Although it can also be formed by SP method etc., in the following explanation, the most preferable GD method will be explained in detail.

The format of the layer region 104 is the layer region 10 according to the GD method.
The manufacturing method is basically the same as No. 3, but the manufacturing conditions are different.

The temperature of the support varies depending on the type of silane gas or a mixed gas mainly composed of silane gas, and in the case of a mixed gas, the mixing ratio thereof, but it is not desirable for the temperature to exceed 400°C. For example, in the case of a mixed gas of SiH ₄ and H ₂ , the support temperature is preferably in the range of 10° C. to 400° C., and in the case of a mixed gas of SiH ₄ and Ar, it is desirable to be in the range of 250° C. to 400° C.

Although the gas flow rate is limited by the capacity of the exhaust system, gas pressure, electrode area, etc., a higher flow rate is desirable.

The gas pressure is in the range of 0.05 Torr to 1 Torr, preferably around 0.1 Torr.

The high frequency power depends on the gas type, plate gas pressure,
Although it varies depending on the electrode area, etc., it is desirable that the deposition rate be at most 3 Å/sec, since as the power increases, it becomes difficult to obtain excellent photoconductivity.

The present invention will be specifically described below with reference to Examples.

Example 1 A layer region 103 was produced using the deposition apparatus shown in FIG.

The base pressure in the deposition chamber 204 is approximately 1×
After exhausting to 10 ^-6 Torr, gas introduction pipe 2
H ₂ gas having a purity of 99.999% or more and containing 2% O ₂ gas was introduced into the deposition chamber 204 through 05 at a partial pressure of about 1×10 ⁻³ Torr. A high frequency power of 13.56MHz was applied to the high frequency coil 210 to obtain an output of about 100W. The other support body 211-
1,211-2 is a heating device 212 while rotating.
was in operation and heated to approximately 350°C. The supports 211-1 and 211-2 are 15 cm x 15
cm Al plate was used. Next, an electron beam generated from an electron gun 208 was irradiated onto a 1.3 KΩcm silicon target housed in a crucible 207, causing silicon particles to fly. The power of the electron gun in this case was approximately 1.5KW. In this way, a layer region 10 with a layer thickness of approximately 30 μm is formed.
3 was formed in about 6 hours.

Next, a layer region 104 was provided on the layer region 103 described above in the following manner.

The support 211-1 or 211-2 provided with the layer region 103 is set on the anode electrode 303 in FIG. 3 as shown in FIG. 102 was formed.

Base pressure...~1×10 ^-6 Torr Reactive gas species...SiH ₄ 10%, H ₂ 90% mixed gas Gas flow rate...10SCCM Gas pressure...0.1Torr High frequency (13.56MHz) power...5W Support temperature: about 200° C. Deposition time: about 60 minutes The layer area obtained was about 1 μm.

Example 2 A 15 cm x 15 cm Al support was set as shown at 305 on the anode electrode 303 in FIG. 3, and a layer region 103 was produced by the 7GD method under the following deposition conditions.

Base pressure...~1×10 ^-6 Torr Reactive gas species...SiH ₄ and O ₂ Gas flow rate SiH ₄ ...80SCCM O ₂ ...1SCCM Gas pressure...0.1Torr High frequency (13.56MHz) power... 150W Support temperature...approximately 350°C Deposition time...6 hours The layer thickness of the layer region 103 obtained under the above conditions is approximately
It was 30 μm. Next, the support temperature was lowered to 200° C., and a layer region 104 having a thickness of about 1 μm was produced following the preparation of layer region 103 under the same deposition conditions as in the production of layer region 104 in Example 1.

Example 3 The electrophotographic image forming members obtained in Examples 1 and 2 were subjected to negative corona charging using a turntable and then exposed to light to measure the surface potential in bright and dark areas.
A schematic diagram of the measuring device in that case is shown in FIG.

The dark area surface potential is DC power supply 401 for corona charging.
The imaging member 40 is charged at a negative charging voltage of about 7 KV using
Negative corona charging was performed on the photoconductive layer of No. 4 for about 0.1 seconds, and the photoconductive layer was moved in the direction of the arrow x, and after 0.1 seconds, the surface potential was measured using a vibrating capacitance probe 405 and an electrometer 406. The distance between Kona charging wire 402 and imaging member 404 is approximately 10 mm.

The bright area surface potential was charged using a tungsten lamp 403 under the same conditions as above, and at an illuminance of 100 lux.
The surface potential was measured after exposure for 0.1 seconds.

The dark area surface potential of the image forming member obtained in Example 1 was approximately 350V, the bright area surface potential was approximately 40V, and the dark area surface potential of the image forming member obtained in Example 2 was approximately 400V.
The bright area surface potential was approximately 60V.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view for explaining the layer structure of the electrophotographic image forming member of the present invention, and FIGS. FIG. 4 is a schematic explanatory diagram for explaining the measuring device in the embodiment. 100... Image forming member, 101... Support, 1
02... photoconductive layer, 103, 104... layer region,
105...Free surface, 201...Base plate, 202...Exhaust port, 203...Belgear,
204...deposition chamber, 205...gas introduction pipe, 20
6...Silicon evaporator, 210...High frequency coil, 211...Support, 212...Radiation heating device, 213...High frequency power supply, 214...DC power supply, 301...Bergear, 302...Cathode electrode, 303 ... Anode electrode, 304 ... Heater, 305 ... Support, 306 ... Rotary pump valve, 307 ... Diffusion pump main valve, 308 ... High frequency power supply, 30
9,310... Reaction gas introduction valve, 401...
DC high voltage power supply, 402...Charging wire, 403
... Tungsten lamp, 404 ... Image forming member, 405 ... Probe, 406 ... Electrometer.

Claims (1)

[Scope of Claims] 1. In an electrophotographic image forming member having a support and a photoconductive layer, the photoconductive layer is composed of an amorphous semiconductor based on silicon atoms and containing hydrogen atoms and/or halogen atoms. and the refractive index n is
A layer area with a layer thickness of 5 μ or more and a filling degree of 2.15 g/cm ³ or more and a layer thickness of 2.5 or more and 3.5 or less.
An electrophotographic image forming member characterized in that it is formed by laminating layer regions having a thickness of 2000 Å to 5 μ. 2. The electrophotographic image forming member according to claim 1, wherein the photoconductive layer contains a p-type or n-type impurity. 3. The electrophotographic imaging member according to claim 1, further comprising a barrier layer between the support and the photoconductive layer.