JP3171972B2 - Electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms an image using electromagnetic waves such as light (here, light in a broad sense, which indicates ultraviolet light, visible light, infrared light, X-rays, .gamma.-rays, etc.). And a photoreceptor for electrophotography used for

[0002]

2. Description of the Related Art In the field of image formation, a photoconductive material for forming a photoreceptive layer in an electrophotographic photoreceptor has high sensitivity, a high SN ratio [photocurrent (Ip) / dark current (Id)], and is irradiated. It is required to have characteristics such as having an absorption spectrum suitable for the spectral characteristics of an electromagnetic wave, fast light response, having a desired dark resistance value, and being harmless to a human body during use. In particular, in the case of an electrophotographic photoreceptor incorporated in an electrophotographic apparatus used in an office as an office machine, the above-mentioned non-polluting property at the time of use is important.

[0003] Non-single-crystal silicon (hereinafter referred to as "A-Si") has recently attracted attention based on this point. For example, German Patent Application Publication No. 274696.
No. 7, No. 2,855,718 and the like describe application as a light receiving member for electrophotography.

FIG. 2 shows a conventional light receiving member 20 for electrophotography.
FIG. 2 is a cross-sectional view schematically showing a layer configuration of No. 0, wherein 201 is a conductive support, 202 is a light receiving layer made of A-Si, and the light receiving layer has a free surface 203. Such an electrophotographic light-receiving member generally heats the conductive support 201 to 50 ° C. to 400 ° C., and performs vacuum deposition, sputtering, ion plating, and the like on the support.
A photosensitive layer (light receiving layer) 202 made of A-Si is formed by a film forming method such as a thermal CVD method, a photo CVD method, and a plasma CVD method. Among them, a plasma CVD method, that is, a method in which a raw material gas is decomposed by direct current, high frequency, or microwave glow discharge to form an A-Si deposited film on a support has been put to practical use.

Japanese Patent Application Laid-Open No. Sho 54-121743 proposes an electrophotographic image forming member comprising an A-Si photoconductive layer containing a support and a photoconductive layer as constituent elements. In this publication, the generation efficiency of photocarriers is improved by forming a depletion layer in the photoconductive layer, the recombination probability is reduced, and the photoresponse speed and the residual potential are improved. In JP-A-57-4053, a depletion layer is provided between a photoconductive layer and a support by a lower barrier layer for preventing injection of carriers having the same polarity as that of minority carriers, and the charge retention ability is improved. We provide photoconductors for electrophotography with high sensitivity.

[0006]

However, a conventional electrophotographic photoreceptor having a photoconductive layer made of an A-Si material has a disadvantage in that the electrophotographic photoreceptor has a dark resistance value, photosensitivity, photoresponsiveness, etc. , Photoconductive properties, and usage environment properties, as well as aging stability and durability, each of which has been individually improved. The fact is that there is room to be done. In other words, in recent years, higher speed and higher image quality have been demanded for electrophotographic apparatuses. As a result, the electrical characteristics and photoconductive characteristics of electrophotographic photoconductors must be improved more than ever.

For example, when an A-Si material is applied to a current electrophotographic photoreceptor, an optical memory, charging ability, residual potential, sensitivity and half-length which have not been a problem in the conventional low-speed charging-exposure-development process. The sharpness of the tone is a problem. In the prior art, when the chargeability is improved, the residual potential and the optical memory tend to be relatively deteriorated, and it has been difficult to achieve both at the same time at a high level. In addition, there is a problem that as the application is made to a high-speed process, unevenness of halftone, that is, roughness becomes more remarkable. In addition, A-Si
When a material is applied, in order to improve the gradation and the color reproducibility, the optical memory and the halftone roughness are required to be more strictly improved.

For this reason, while the characteristics of the A-Si material itself are improved, when designing the electrophotographic photoreceptor, the layer constitution and the chemical composition of each layer are set so as to solve the above-mentioned problems. It is necessary to improve the production method from a comprehensive viewpoint.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and solves various problems in the conventional electrophotographic photoreceptor having a light-receiving layer composed of a material having silicon atoms as a base. It is intended to do so. In other words, even when applied to an electrophotographic apparatus using a high-speed process, it exhibits excellent electrical characteristics that do not cause a problem of charging ability, residue, sensitivity, and optical memory, and furthermore, provides a clear image without halftone roughness. Another object of the present invention is to provide a photoconductor for electrophotography which can easily obtain a high-quality image with high resolution and to which a normal electrophotographic method can be applied very effectively.

[0010]

According to the present invention, there is provided a conductive support, a photoconductive layer, and a carrier provided between the conductive support and the photoconductive layer, the carrier being prevented from being injected into the photoconductive layer from the side of the support. In an electrophotographic photoreceptor having a barrier layer having a function, the photoconductive layer and the barrier layer are made of a non-monocrystalline material containing hydrogen mainly containing silicon, and the photoconductive layer When the electrophotographic photoconductor is positively charged, the difference ΔE between the half of the optical band gap and the activation energy is 0.01 eV or more and 0.3 eV.
When the electrophotographic photoconductor is negatively charged, the ΔE is 0.01 eV or more and 0.3
eV or less, and the conductivity type of the barrier layer is ΔE when the electrophotographic photosensitive member is positively charged.
Is a p-type of 0.01 eV or more and 0.3 eV or less, and when the electrophotographic photoreceptor is negatively charged, the ΔE is 0.01 eV or more and 0.3 eV or less.
And the localized state density of the barrier layer is 1 × 10 ¹⁷
cm ⁻³ to 5 × 10 ¹⁹ cm ⁻³ , dark resistivity of the photoconductive layer
Is 5 × 10 ⁹ Ωcm or more .

[0011]

Further, the dark resistivity of the photoconductive layer is 5 × 10 ⁹ Ω.
cm or more.

The photoconductive layer has a thickness of 1 to 70 μm.
m, the thickness of the barrier layer is desirably 0.1 to 5 μm.

The local level density can be controlled by adding oxygen and / or nitrogen and / or carbon to the barrier layer.

[0015] If necessary, a charge injection blocking layer for preventing carrier injection is provided on the photoconductive layer.

Hereinafter, embodiments of the present invention will be described.

FIG. 1 is a diagram schematically illustrating the layer structure of a preferred embodiment of the electrophotographic photosensitive member of the present invention. Electrophotographic photoreceptor 1100 shown in FIG.
Is a conductive support 1101 for an electrophotographic photosensitive member.
A barrier layer 1102 made of A-Si and an AS
i. a photoconductive layer 1103 having a layer structure composed of a surface layer 1104 as a protective layer and a charge injection blocking layer provided as needed, and the light receiving layer 1105 has a free surface. 1106.

The photoconductive layer 1103 in the present invention extends the life of the photocarriers generated by image exposure by making the majority carriers the same in charge polarity, and improves the runnability. For this reason, the residual potential and the sensitivity are improved, and a remarkable effect is particularly observed in reducing the optical memory. However, if the Fermi level of the photoconductive layer 1103 deviates from the center of the optical band gap, the dark resistance decreases. Therefore, the photoconductive layer 1103 used in the present invention may have a slightly lower resistance than the conventional one. However, in order to further obtain the effect of the present invention, the difference between the activation energy and 1/2 of the optical band gap is set within 0.01 to 0.3 eV, and the dark resistance is preferably 5 × 10 5 ^It is preferably designed to be ⁹ Ωcm or more, optimally 10 ¹⁰ Ωcm or more. In this range, the improvement of the charging ability and the improvement of the optical memory are simultaneously satisfied.

The thickness of the photoconductive layer 1103 in the present invention is appropriately determined to a desired value in accordance with the process speed and purpose of the electrophotographic apparatus to be applied. Is preferably in the range of 2 to 50 μm.

The barrier layer 1102 of the present invention has a conduction type of the same polarity as the conduction type of the photoconductive layer 1103, and has a conduction type of a weak p-type that is comparable to or less than that of the photoconductive layer 1103. Alternatively, carriers are prevented from being injected from the support into the photoconductive layer 1103 by having an n-type and providing the barrier layer 1102 with an appropriate localized level density. Conventionally, in a photoreceptor having a stopping power using a depletion layer, most of the charging electric field is applied to the depletion layer.
3 tended to weaken, and the photocarriers in the photoconductive layer 1103 did not have sufficient mobility. The insufficiency of the optical carrier's running property is emphasized especially when used in a high-speed process, and the subtle film quality difference of each part of the photoreceptor is remarkably reflected, resulting in halftone density unevenness, so-called roughness. Would be. In order to prevent this phenomenon, the barrier layer 1102 of the present invention has the same conductivity type as that of the photoconductive layer 1103 and the same strength as that of the photoconductive layer 1103. Such a depletion layer is not generated. Further, by setting an appropriate localized level density in the barrier layer 1102, carriers injected from the support are captured, and a stopping power is obtained by forming a space charge. I have. With this configuration, a depletion layer is not generated at the interface between the photoconductive layer 1103 and the barrier layer 1102, and all the above-mentioned problems are solved. Further, since the traveling type of the photocarrier is sufficient because of the same conductivity type as the charging polarity, the residual potential and the sensitivity are improved.

In the present invention, if the localized level density of the barrier layer 1102 for obtaining the above-mentioned effect is too high, the traveling property of the optical carrier is deteriorated, which causes a residual potential. In addition, hopping conduction occurs, and conversely, injection from the support increases, so that the density is preferably 5 × 10 ¹⁹ cm ⁻³ or less. Also, if the localized level density is too small, the stopping power decreases,
It is preferably 1 × 10 ¹⁷ cm ⁻³ or more. To set a desired localized level density, film formation conditions, for example, a support temperature, power,
By controlling the degree of vacuum or the like, a film having a desired value can be formed. Further, the control can be made to some extent by the doping amount of the impurity for controlling the conduction type. However,
In this case, it is desirable in the present invention that the difference ΔE between 1/2 of the band gap and the activation energy is within 0.01 to 0.3 eV. Further, the local level density can be controlled by containing any, a combination, or all of impurity elements such as oxygen, nitrogen, and carbon. Further, it can be controlled even by changing the type and flow rate of the source gas.

In the case of A-Si, the localized level density is generally "photothermal defection".
spectroscopy "(PDS)," const
Antphotocurrent method "(C
PM) or the like. The present inventors mainly determined the localized level density using CPM, but partially obtained the sample having a high localized level density using PDS.

The lower limit of the thickness of the barrier layer is limited by a thickness that can sufficiently prevent carrier injection from the support 1101. Although this film thickness naturally correlates with the localized level density in the barrier layer 1102, a specific numerical value for expressing the effect of the present invention is usually 0.1 μm or more, preferably 0.1 μm or more.
It is desirable that the thickness be 5 μm or more. On the other hand, the upper limit of the film thickness is determined based on the balance between the charging ability desired for the electrophotographic photoreceptor and the residual potential.
m, preferably 3 μm.

In the present invention, in order to make the photoconductive layer 1103 and the barrier layer 1102 contain hydrogen, for example, a silane (Sil) such as SiH ₄ or Si ₂ H ₆ may be used when these layers are formed.
ane) and the like, and these compounds can be decomposed by glow discharge plasma CVD to automatically contain hydrogen in accordance with the growth of the film. Alternatively, a film containing hydrogen can be formed by a reactive sputtering method in a hydrogen atmosphere.

According to the knowledge of the present inventors, the hydrogen content of the photoconductive layer 1103 and the barrier layer 1102 of the present invention depends on whether or not the formed photoreceptor 1100 can be sufficiently applied on an actual surface. It has been found to be one of the major factors influencing and extremely important. Photoconductive layer 110 of the present invention
In order that the barrier layer 1102 and the barrier layer 1102 can be sufficiently applied to the actual surface, the amount of hydrogen contained in each layer is usually 1 to 4
It is desirably 0 atomic%, preferably 5 to 30 atomic%. In order to control the amount of hydrogen contained in each layer, for example, the temperature of the support at the time of film formation and / or the amount of the starting material used to contain hydrogen and the amount of the starting material introduced into the deposition apparatus system and the discharge power can be controlled. Good.

The photoconductive layer 1103 and the barrier layer 1102 are p
In order to obtain the type or the n-type, an atom for controlling conductivity, for example, a group III atom or a group V atom may be introduced into a deposition apparatus together with another gas when forming a layer. Examples of the atom for controlling the conductivity include so-called impurities in the semiconductor field, and an atom belonging to Group III of the periodic table that provides p-type conductivity (hereinafter referred to as “III
Group atom) or an atom belonging to Group V of the periodic table that provides n-type conduction characteristics (hereinafter referred to as “Group V atom”).

Specific examples of Group III atoms include B
(Boron), Al (aluminum), Ga (gallium),
There are In (indium), Tl (thallium) and the like, and B, Al and Ga are particularly preferable. Specific examples of Group V atoms include P (phosphorus), As (arsenic), Sb (antimony), and Bi (bismuth), and P and As are particularly preferable.

The content of atoms for controlling the conductivity contained in the photoconductive layer 1103 and the barrier layer 1102 may be such that the Fermi level is controlled so as to achieve the object of the present invention. However, specific numerical values are usually 1 × 10 ^{−3 to} 5 × 10 ⁴ atomic ppm, preferably 1 × 10 ⁻² to 1 × 10 ⁴ atomic ppm, more preferably 1 × 10 ⁻² to 1 × 10 ⁴ atomic ppm.
It is desirable that the concentration be 10 ^{-1 to} 5 × 10 ³ atomic ppm.

In the present invention, the photoconductive layer 1103 and the barrier layer 1102 are formed by appropriately setting film forming parameter numerical conditions so as to obtain desired characteristics by a vacuum deposited film forming method. Specifically, for example, a glow discharge method (a low-frequency CVD method, a high-frequency CVD method,
AC discharge CVD method such as VD method, or DC discharge CVD method
Method, a sputtering method, a vacuum evaporation method, an ion plating method, a photo CVD method, a thermal CVD method, and the like. These thin film deposition methods are appropriately selected and adopted depending on factors such as manufacturing conditions, the degree of load under capital investment, the manufacturing scale, and the characteristics desired for the electrophotographic photoreceptor to be produced. The glow discharge method, since it is relatively easy to control the conditions for producing an electrophotographic photosensitive member having
A sputtering method and an ion plating method are preferable. These methods may be used together in the same apparatus system.

The conductive support 1 used in the present invention
As 101, for example, Al, Cr, Mo, Au, I
Examples include metals such as n, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof, such as stainless steel. Also, at least the surface of the electrically insulating support such as a film or sheet of a synthetic resin such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, polyamide, etc., at least on the side on which the light-receiving layer is formed, such as a glass or ceramic. Can be used. Further, it is more preferable that the surface on the side opposite to the side on which the light receiving layer is formed is also subjected to a conductive treatment.

The shape of the support 1101 can be a cylindrical or plate-like endless belt having a smooth surface or an uneven surface, and its thickness is appropriately determined so that a desired electrophotographic photosensitive member can be formed. However, the electrophotographic photoconductor 110
When flexibility as 0 is required, it can be made as thin as possible within a range where the function as a support can be sufficiently exhibited. However, the production and handling of the support 1101 are usually 10 μm in view of mechanical strength and the like.
It is above.

In particular, when image recording is performed using coherent light such as laser light, unevenness is provided on the surface of the support 1101 in order to eliminate an image defect due to a so-called interference fringe pattern appearing in a visible image. Is also good. The irregularities provided on the surface are described in JP-A-60-168156 and JP-A-60-168156.
It is prepared by a known method described in JP-A-178457 and JP-A-60-225854. Further, as another method for eliminating the image defect, the surface of the support 1101 may be provided with a concave and convex shape by a plurality of spherical trace depressions. That is, the surface of the support 1101 is
Has finer irregularities than the required resolving power, and the irregularities are caused by a plurality of spherical trace depressions. The unevenness due to the plurality of spherical trace dents provided on the surface of the support is created by a known method described in JP-A-61-231561.

The surface layer 1104 provided as required improves the surface hardness, serves as a protective layer for improving abrasion resistance, prevents charging charges from being injected into the photoconductive layer, and improves charging performance. It has a role as a charge injection blocking layer. Typical examples of the material effectively used as the material for forming the surface layer 1104 include Si, SiC, SiN, and S
Non-single crystal materials such as iO, Al ₂ O ₃ , SiO, SiO ₂
Indefinite insulating compounds such as, polyethylene, polycarbonate, polyurethane, organic insulating compounds such as parylene,
And the like. The thickness of the surface layer 1104 is usually selected to be about 0.1 μm to 2 μm.

In the present invention, the barrier layer, the photoconductive layer, and the surface layer may contain at least one element selected from Group Ia, IIa, VIa, and VIII of the periodic table to a degree of contamination. good. The element may be uniformly distributed throughout the photoconductive layer, or may be uniformly distributed in the photoconductive layer, but may be unevenly distributed in the layer thickness direction. There may be a part containing. Specific examples of Group Ia atoms include Li (lithium), Na (sodium), and K (potassium).
Examples of group IIa atoms include Be (beryllium), Mg (magnesium), Ca (calcium), Sr (strontium), and Ba (barium). Specific examples of Group VIa atoms include Cr (chromium), Mo (molybdenum), and W (tungsten). Examples of Group VIII atoms include Fe (iron),
Co (cobalt), Ni (nickel) and the like can be mentioned.

Hereinafter, an apparatus and a method for forming a deposited film by a DC discharge plasma CVD method will be described in detail.

FIG. 3 shows a DC discharge plasma CVD (hereinafter referred to as "D
FIG. 1 is an explanatory diagram of a schematic configuration showing an example of an apparatus for manufacturing an electrophotographic photosensitive member by a method described as “C-PCVD”).

The structure of the apparatus for manufacturing a deposited film by the DC-PCVD method shown in FIG. 3 is as follows. This device is roughly composed of a deposition device (3100), a source gas supply device (3200), and an exhaust device (not shown) for reducing the pressure inside the reaction vessel (3111). A cylindrical support (3112) and a heater for heating the support (311) are provided in a reaction vessel (3111) in the deposition apparatus (3100).
3) A source gas introduction pipe (3114) is provided.

The source gas supply device (3200) is made of SiH
₄ , H ₂ , CH ₄ , NO, NH ₃ , B ₂ H _6, etc.
~ 3236,3241 ~ 3246,3251 ~ 325
6) and mass flow controllers (3211-32)
16), and the cylinder for each source gas is a valve (3
260) is connected to a gas introduction pipe (3114) in the reaction vessel (3111).

The formation of a deposited film using this apparatus can be performed, for example, as follows.

First, the cylindrical support (3112) is set in the reaction vessel (3111), and the inside of the reaction vessel (3111) is evacuated by an exhaust device (not shown) (for example, a vacuum pump). Subsequently, the temperature of the cylindrical support (3112) is controlled to a predetermined temperature of 20 ° C. to 500 ° C. by the support heating heater (3113).

A source gas for forming a deposited film is supplied to a reaction vessel (31).
In order to make the gas flow into 11), the gas cylinder valve (323)
1-3236), leak valve of reaction vessel (3117)
Is closed, and check that the inlet valve (3
241 to 246), outflow valve (3251 to 325)
6) After confirming that the auxiliary valve (3260) is open, first open the main valve (3118) and exhaust the reaction vessel (3111) and the inside of the gas pipe (3116).

Next, the reading of the vacuum gauge (3119) was about 5 × 1.
When the ^pressure reaches 0 ^-6 Torr, the auxiliary valve (3260)
Close the outlet valves (3251 to 256).

Thereafter, gas cylinders (3221 to 322)
From 6), each gas is introduced by opening the valves (3231 to 236), and each gas pressure is adjusted to ² kg / cm ² by the pressure regulators (3261 to 266). Next, the inflow valves (3241 to 246) are gradually opened, and each gas is introduced into the mass flow controllers (3211 to 216).

After the preparation for film formation is completed as described above, the barrier layer and the photoconductive layer are formed on the cylindrical support (3112).

When the temperature of the cylindrical support (3112) reaches a predetermined temperature, necessary ones of the outflow valves (3251 to 256) and the auxiliary valve (3260) are gradually opened, and a predetermined amount is opened from the gas cylinder (3221 to 226). Gas from the reaction vessel (311) via the gas introduction pipe (3114).
Introduce in 1). Next, the mass flow controller (3
According to 211 to 216), each raw material gas is adjusted so as to have a predetermined flow rate. At this time, the opening of the main valve (3118) is adjusted while watching the vacuum gauge (3119) so that the pressure in the reaction vessel (3111) becomes a predetermined pressure of 1 Torr or less. When the internal pressure is stabilized, the DC power supply (3115) is set to a desired voltage and the reaction vessel (3115) is set.
A DC voltage is applied in 11) to generate a DC glow discharge. The raw material gas introduced into the reaction vessel is decomposed by the discharge energy, and a deposited film containing silicon as a main component is formed on the cylindrical support (3112). After the formation of the desired film thickness, the supply of the DC power supply (3115) is stopped, the outflow valve is closed to stop the gas from flowing into the reaction vessel, and the formation of the deposited film is completed.

By repeating the same operation a plurality of times, a light receiving layer having a desired multilayer structure is formed.

When forming each layer, it goes without saying that all outflow valves other than necessary gas are closed, and each gas is supplied to the reaction vessel (311).
1) Close the outflow valves (3251 to 256), open the auxiliary valve (3260), and further open the main valve to avoid remaining in the piping from the outflow valves (3251 to 256) to the reaction vessel (3111). Valve (31
The operation of fully opening 18) and once evacuating the system to a high vacuum is performed as necessary.

To achieve uniform film formation, the cylindrical support (3112) is rotated at a predetermined speed by a driving device (not shown) during the film formation.

It goes without saying that the above-mentioned gas types and valve operations are changed according to the conditions for forming each layer.

[0050]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. (Example 1) Using the apparatus for manufacturing a photoreceptor for electrophotography shown in FIG. 3, on a mirror-finished aluminum cylinder, according to the procedure described in detail above, by a DC glow discharge method under the production conditions shown in Table 1. An electrophotographic photosensitive member for positive charging was prepared. In this embodiment, the value of ΔE is set to 0.05 eV (p-type) and 0.1 eV by changing the amount of B ₂ H ₆ and H ₂ in the photoconductive layer.
(P type) and 0.25 eV (p type). The value of ΔE is
A sample was prepared in advance on a glass substrate, and an electrophotographic photoreceptor was prepared under the same conditions. It was confirmed that the dark resistance of each film was 5 × 10 ⁹ Ωcm or more.

The barrier layer of this embodiment has a ΔE of 0.1 eV.
(P-type) having a localized level density of 5 × 10 ¹⁷ cm ⁻³ was used.

The produced electrophotographic photosensitive member was set in an electrophotographic apparatus in which a copying machine NP-9800 made by Canon was modified for an experiment, and the charging ability at the time of positive charging, residual potential, optical memory (ghost), and roughness were evaluated. Was done. Each item is
Evaluation was made by the following method. Electrical characteristics Charging ability: An electrophotographic photoreceptor is installed in an experimental device, a high voltage of +6 kV is applied to the charger to perform corona charging, and the surface electrometer measures the dark surface of the electrophotographic light-receiving member. Measure the potential.

Residual potential: The photoconductor for electrophotography is charged to a constant dark area surface potential. Then, a relatively strong light of a constant light amount is immediately irradiated. The light image was irradiated with light excluding light in the wavelength range of 550 nm or less using a filter using a halogen lamp light source. At this time, the surface potential of the light portion of the electrophotographic photosensitive member is measured with a surface voltmeter.

In each case, ◎ indicates “very good”, は indicates “good”, Δ indicates “no problem in practical use”, and × indicates “problem in practical use”. Image evaluation Optical memory (Coast): A ghost test chart (part number: FY9-9040) manufactured by Canon Inc. has a reflection density of 1, 1,
A た 5 mm ghost chart recognized on a halftone copy in a copy image obtained by placing a black circle of ノ ン 5 mm on the front end of the image on the platen and overlaying a halftone chart made by Canon on the そ の 5 mm The difference between the reflection density and the reflection density of the halftone portion was measured.

Gasket: A halftone chart made by Canon (part number FY9-9042) is placed on a document table and copied on a copy image obtained when a circular area having a diameter of 0.05 mm is defined as 100 units. The image density at the point was measured, and the variation in the image density was evaluated.

In each case, ◎ indicates “particularly good”, Δ indicates “good”, Δ indicates “no problem in practical use”, and x indicates “problem in practical use”.

[0057]

[Table 1] Comparative Example 1 An electrophotographic photosensitive member for positive charging was manufactured in the same manner as in Example 1 under the manufacturing conditions shown in Table 2. In this comparative example, the value of ΔE was changed to 0 eV by changing the amount of B ₂ H ₆ in the photoconductive layer.
(I-type) and 0.1 eV (n-type) dark resistance is 5 ×
Drum of 10 ⁹ Ωcm or more and ΔE of 0.2 eV (p
A photoreceptor having a dark resistance of less than 5 × 10 ⁹ Ωcm was prepared by the following method.

The produced electrophotographic photosensitive member was evaluated in the same manner as in Example 1.

Table 2 shows the results of Example 1 and Comparative Example 1. The conductivity type of the photoconductive layer is the same polarity (p-type) as the charging potential, ΔE is within 0.01 to 0.3 eV, and dark resistance is 5
It can be seen that the optical memory is improved at × 10 ⁹ or more.

[0060]

[Table 2] Example 2 In the same manner as in Example 1, an electrophotographic photoconductor for negative charging was manufactured using the apparatus for manufacturing an electrophotographic photoconductor shown in FIG. In the present embodiment, the value of ΔE is changed to 0.05 eV (n-type), 0.1 eV (n-type), 0.1 eV by changing the amount of B ₂ H ₆ or PH ₃ and H ₂ in the photoconductive layer.
25 eV (n). For the value of ΔE, a sample was prepared on a glass substrate in advance, and a photoconductor for electrophotography was prepared under the same conditions. Each film has a dark resistance of 5 × 10 ⁹ Ωcm
It was confirmed that there was.

The barrier layer of this embodiment has a ΔE of 0.3 eV.
(N-type) and those having a localized level density of 5 × 10 ¹⁷ cm ⁻³ were used.

The produced electrophotographic photosensitive member was set in an electrophotographic apparatus in which a copying machine NP-9800 manufactured by Canon Inc. was modified for experiments, and the charging ability at the time of negative charging, residual potential, roughness, and ghost were the same as in Example 1. Was evaluated.

[0063]

[Table 3] Comparative Example 2 An electrophotographic photosensitive member for negative charging was manufactured in the same manner as in Example 1 under the manufacturing conditions shown in Table 2. In this comparative example, by changing the amount of B ₂ H ₆ or PH ₃ and H ₂ in the photoconductive layer,
A value of ΔE of 0 eV (i type), a drum having a dark resistance of 0.1 eV (p type) of 5 × 10 ⁹ Ωcm or more, and a value of ΔE of 0.2
A photoreceptor having a dark resistance of less than 5 × 10 ⁹ Ωcm at eV (n-type) was prepared.

The produced electrophotographic photosensitive member was evaluated in the same manner as in Example 2.

Table 4 shows the results of Example 2 and Comparative Example 2. The conduction type of the photoconductive layer is the same polarity as the charging potential and Δ
E is within 0.01 to 0.3 eV and dark resistance is 5 × 10 ⁹
The above shows that the optical memory is improved.

[0066]

[Table 4] (Example 3) Using the apparatus for manufacturing a photoreceptor for electrophotography shown in FIG. 3, on a mirror-finished aluminum cylinder, according to the procedure described in detail above, by a DC glow discharge method under the production conditions shown in Table 5. An electrophotographic photosensitive member for positive charging was prepared. In this embodiment, the barrier layer is formed by ΔE: 0.01 eV (p-type), ΔE:
E: 0.08 eV (p-type), ΔE: 0.2 eV (p
) And ΔE: 0.3 eV (p-type).
In each case, the localized level density was 5 × 10 ¹⁷ cm ⁻³ . still,
The control of ΔE and the localized level density was performed by controlling the flow rate of the B ₂ H ₆ gas and the film formation rate during the film formation. Each parameter was measured by preparing a sample on a glass substrate in advance, and a photoconductor for electrophotography was prepared under the same conditions.

The photoconductive layer of this embodiment has a ΔE of 0.11.
eV (p type) and dark resistance of 1 × 10 ¹² Ωcm were used.

The produced electrophotographic photosensitive member was set in an electrophotographic apparatus in which a copying machine NP-9800 manufactured by Canon Inc. was modified for an experiment, and the charging ability at the time of positive charging, residual potential, roughness, and ghost were evaluated.

[0069]

[Table 5] Comparative Example 3 An electrophotographic photosensitive member for positive charging was manufactured in the same manner as in Example 3. In this comparative example, the barrier layer was set to ΔE: 0 eV
(I type), ΔE: 0.32 eV (p type), ΔE: 0.1
5 eV (n-type) types were created. The localized level density was 5 × 10 ¹⁷ cm ⁻³ as in Example 3.

The produced electrophotographic photosensitive member was evaluated in the same manner as in Example 3.

Table 6 shows the results of Example 3 and Comparative Example 3. The photoreceptor of the present invention has improved halftone roughness.

[0072]

[Table 6] Example 4 In the same manner as in Example 3, an electrophotographic photoconductor for negative charging was manufactured using the apparatus for manufacturing an electrophotographic photoconductor shown in FIG. In the present embodiment, the barrier layer is formed with ΔE: 0.01 eV (n-type) and ΔE: 0.08 eV (n
Type), ΔE: 0.2 eV (n type), ΔE: 0.3 eV
Four types (n-type) were prepared. In each case, the localized level density was 5 × 10 ¹⁷ cm ⁻³ . Note that the control of ΔE and the localized level density was performed by controlling the flow rate of the B ₂ H ₆ gas or B ₂ H ₆ gas and the deposition rate during the deposition. Each parameter was measured by preparing a sample on a glass substrate in advance, and a photoconductor for electrophotography was prepared under the same conditions.

The photoconductive layer of this embodiment has a ΔE of 0.11.
eV (n-type) with a dark resistance of 1 × 10 ¹² Ωcm was used.

The produced electrophotographic photosensitive member was set in an electrophotographic apparatus in which a copying machine NP-9800 manufactured by Canon Inc. was modified for an experiment, and the charging ability at the time of negative charging, residual potential, roughness, and ghost were evaluated.

[0075]

[Table 7] (Comparative Example 4) An electrophotographic photosensitive member for negative charging was produced under the same conditions as in Example 4. In this comparative example, the barrier layer is represented by ΔE:
0 eV (i type), ΔE: 0.32 eV (n type), ΔE:
Three types of 0.15 eV (p-type) were prepared. The localized level density was 5 × 10 ¹⁷ cm ⁻³ as in Example 4.

The produced electrophotographic photosensitive member was evaluated in the same manner as in Example 4.

Table 8 shows the results of Example 4 and Comparative Example 4. The photoreceptor of the present invention has improved halftone roughness.

[0078]

[Table 8] (Example 5) Using the apparatus for manufacturing a photoreceptor for electrophotography shown in FIG. 3, on a mirror-finished aluminum cylinder, according to the procedure described in detail above, by the DC glow discharge method under the manufacturing conditions shown in Table 9 An electrophotographic photosensitive member for positive charging was prepared. In this embodiment, the barrier layer is ΔE: 0.08 eV (p-type), and the local level density is 1 × 10 ¹⁷ cm ⁻³ and 1 × 10 ¹⁸ cm.
^-3 , 5 × 10 ¹⁹ cm ^-3 were prepared. Note that the control of ΔE and the localized level density was performed by controlling the flow rates of the B ₂ H ₆ gas and the H ₂ gas during the film formation. Each parameter was measured by preparing a sample on a glass substrate in advance, and a photoconductor for electrophotography was prepared under the same conditions.

The photoconductive layer of this embodiment has a ΔE of 0.11.
eV (p type) and dark resistance of 1 × 10 ¹² Ωcm were used.

The produced electrophotographic photosensitive member was set in an electrophotographic apparatus in which a copying machine NP-9800 manufactured by Canon Inc. was modified for an experiment, and the charging ability at the time of positive charging, residual potential, roughness, and ghost were evaluated.

[0081]

[Table 9] Comparative Example 5 An electrophotographic photosensitive member for positive charging was produced in the same manner as in Example 3. In this comparative example, the barrier layer was set to ΔE: 0.0
8 eV (p-type) and a local level density of 1 × 10 ¹⁶ c
Three types of m ^-3 , 5 × 10 ¹⁶ cm ^-3 and 8 × 10 ¹⁹ cm ^-3 were prepared.

The produced electrophotographic photosensitive member was evaluated in the same manner as in Example 5.

The results of Example 5 and Comparative Example 5 are shown in Table 10. The photoreceptor of the present invention has improved halftone roughness.

[0084]

[Table 10] (Example 6) In the same manner as in Example 3, an electrophotographic photoconductor for negative charging was manufactured under the manufacturing conditions shown in Table 11 using the apparatus for manufacturing an electrophotographic photoconductor shown in FIG. In this embodiment, the barrier layer is set to ΔE: 0.08 eV (n-type), and the localized level density is 1
× 10 ¹⁷ cm ^-3 , 1 × 10 ¹⁸ cm ^-3 , 5 × 10 ¹⁹ cm ^-3
Were created. Note that the control of ΔE and the localized level density was performed by controlling the flow rates of the B ₂ H ₆ gas and the H ₂ gas during the film formation. Each parameter was measured by preparing a sample on a glass substrate in advance, and a photoconductor for electrophotography was prepared under the same conditions.

The photoconductive layer of this embodiment has a ΔE of 0.11.
eV (n-type) with a dark resistance of 1 × 10 ¹² Ωcm was used.

The produced electrophotographic photosensitive member was set in an electrophotographic apparatus in which a copying machine NP-9800 made by Canon was modified for an experiment, and the charging ability at the time of negative charging, residual potential, roughness, and ghost were evaluated.

[0087]

[Table 11] (Comparative Example 6) In the same manner as in Example 4, an electrophotographic photosensitive member for negative charging was produced. In this comparative example, the barrier layer was set to ΔE: 0.0
8 eV (p-type) and a local level density of 1 × 10 ¹⁶ c
Three types of m ^-3 , 5 × 10 ¹⁶ cm ^-3 and 8 × 10 ¹⁹ cm ^-3 were prepared.

The produced electrophotographic photosensitive member was evaluated in the same manner as in Example 4.

Table 12 shows the results of Example 6 and Comparative Example 6. The photoreceptor of the present invention has improved halftone roughness.

[0090]

[Table 12] (Example 7) The same experiment as in Example 5 was performed. However, in the present embodiment, the local level density was controlled by adjusting the NO gas flow rate instead of the film forming speed, and a clear image was obtained in exactly the same manner as in the fifth embodiment. (Example 8) The same experiment as in Example 6 was performed. However, in this embodiment, when the local level density was controlled by adjusting the flow rate of the NO gas instead of the film forming speed, a clear image was obtained in exactly the same manner as in the sixth embodiment. (Example 9) The same experiment as in Example 5 was performed. However, in the present embodiment, the local level density was controlled by adjusting the flow rate of the CH ₄ gas instead of the film forming speed. As a result, a clear image was obtained in exactly the same manner as in the fifth embodiment. (Example 10) The same experiment as in Example 6 was performed. However, in the present embodiment, the local level density was controlled by adjusting the flow rate of the CH ₄ gas instead of the film forming speed. As a result, a clear image was obtained in the same manner as in the sixth embodiment.

[0091]

As described above, according to the electrophotographic photoreceptor of the present invention, the conventional electrophotographic photoreceptor made of A-Si has recently been required to have high speed and high image quality. It can solve various problems when applied to an electrophotographic apparatus, and exhibits particularly excellent electrical characteristics, optical characteristics, photoconductive characteristics, and image characteristics.

In particular, in the present invention, by setting the conductivity type of the photoconductive layer to a weak conductivity type having the same polarity as the charging polarity, the residual potential and the optical memory can be improved without deteriorating the charging ability. Further, by setting the conductivity type of the barrier layer to the same polarity and the same strength as that of the photoconductive layer, a depletion layer is prevented from being formed between the photoconductive layer and the barrier layer. By appropriately controlling the density, injection of carriers from the support is effectively prevented. With the above configuration, it is possible to suppress the image roughness in the halftone generated in the high-speed process.

[Brief description of the drawings]

FIG. 1 is a schematic layer configuration diagram for explaining a layer configuration of a preferred embodiment of an electrophotographic light-receiving member of the present invention.

FIG. 2 is a schematic layer configuration diagram showing an example of a layer configuration of a conventional light receiving member for electrophotography.

FIG. 3 is an example of an apparatus for forming a light receiving layer of the electrophotographic light receiving member of the present invention, and is a schematic diagram of an apparatus for manufacturing an electrophotographic light receiving member by a glow discharge method using direct current (DC). FIG.

[Explanation of symbols]

 Reference Signs List 1100,200 Electrophotographic photoreceptor 1101,201 Conductive support 1102 Barrier layer 1103 Photoconductive layer 1104 Surface layer 1105,202 Light receiving layer 1106,203 Free surface 3100 Deposition device 3111 Reaction vessel 3112 Cylindrical support 3113 Support Heater for heating 3114 Source gas introduction pipe 3115 DC power supply 3116 Source gas pipe 3117 Reaction vessel leak valve 3118 Main exhaust valve 3119 Vacuum gauge 3200 Source gas supply device 3211-316 Mass flow controller 3221-226 Source gas cylinder 3231-236 Source gas cylinder valve 3241 3246 Gas inflow valve 3251-256 Gas outflow valve 3261-266 Pressure regulator

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 5/08

Claims (4)

(57) [Claims] 1. A conductive support, a photoconductive layer, and a barrier layer provided therebetween and having a function of preventing injection of carriers into the photoconductive layer from a side of the support. In the electrophotographic photoreceptor, the photoconductive layer and the barrier layer are made of a non-single crystalline material containing silicon and mainly containing hydrogen, and the conduction type of the photoconductive layer is When the photoreceptor is positively charged, the difference ΔE between the half of the optical band gap and the activation energy is 0.01 eV or more, and the difference ΔE is 0.01 eV or more.
When the p-type is 3 eV or less and the electrophotographic photoconductor is negatively charged, the ΔE is 0.01 eV or more,
When the conductivity type of the barrier layer is positively charged, the ΔE is 0.01 eV or more, and the conductivity type of the barrier layer is 0.01 eV or more.
When the p-type is 3 eV or less and the electrophotographic photoconductor is negatively charged, the ΔE is 0.01 eV or more,
N-type of 0.3 eV or less, and the localized state density of the barrier layer is 1 × 10 ¹⁷ cm ⁻³ to 5 × 10 ¹⁹ cm ⁻³ ;
A photoconductor for electrophotography, wherein a dark resistivity of the photoconductive layer is 5 × 10 ⁹ Ωcm or more . 2. The method according to claim 1, wherein said barrier layer comprises oxygen and / or nitrogen and / or
2. The electrophotographic photoconductor according to claim 1 , further comprising carbon. 3. The electrophotographic photosensitive member according to claim 1 or claim 2, characterized in that a charge injection blocking layer for preventing injection of carriers into the upper portion of the photoconductive layer. 4. according to any one of claims 1 to 3 film thickness of the photoconductive layer is 1～70Myuemu, the thickness of the barrier layer is characterized in that it is a 0.1~5μm Electrophotographic photoreceptor.