JPS62115456A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having superior electrostatic chargeability, low residual potential, high sensitivity in a wide wavelength region and superior environmental resistance by forming a laminate consisting of amorphous silicon and microcrystalline silicon as a photoconductive layer. CONSTITUTION:The 1st a-Si layer 106, a muC-Si layer 104 and the 2nd a-Si layer 105 are successively laminated on a support 101 to form a photoconductive layer 103. The 2nd a-Si layer 105 contains at least one among C, O and N. The 1st a-Si layer 106 contains an atom for controlling the type of conductivity and at least one among C, O and N. The 1st a-Si layer 106 is composed of the 1st region 107 and the 2nd region 108 each having photoconductivity. The concns. of the atom for controlling the type of conductivity and at least one among C, O and N in the 1st region 107 are higher than those in the 2nd region 108 and the atoms in the 1st region 107 have ununiform concn. distributions in the thickness direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor having excellent charging characteristics, photosensitivity characteristics, environmental resistance, and the like.

[Prior art and its problems] Conventionally, as materials for forming the photoconductive layer of an electrophotographic photoreceptor, inorganic materials such as CdS, ZnO, Se, 5e-Te, or amorphous silicon, or poly-N-vinylcarbazole (PVCz) have been used. Or trinitrofluorene (T
Organic materials such as NF) are used. however,
These conventional photoconductive materials have various problems in terms of photoconductive properties or manufacturing, and these materials are used depending on the purpose of use, sacrificing the properties of the photoreceptor system to some extent.

For example, Se and CdS are materials that are harmful to the human body, and special consideration must be given to safety measures when manufacturing them. Therefore, there are problems in that the manufacturing equipment becomes complicated and the manufacturing cost is high, and in particular, Se needs to be recovered, which adds to the recovery cost. Also,
In the Se or 5e-Te system, the crystallization temperature is 65°C
Therefore, during repeated copying, problems with the photoconductive properties arise due to residual snow, etc., and therefore, the service life is short and practicality is low.

Furthermore, ZnO is susceptible to oxidation-reduction and is significantly affected by the environmental atmosphere, resulting in a problem of low reliability in use.

Furthermore, organic photoconductive materials such as PVCz and TNF are suspected to be carcinogens and present human health concerns, and organic materials have low thermal stability and abrasion resistance. , has the disadvantage of short lifespan.

On the other hand, amorphous silicon (hereinafter abbreviated as a-3i)
has recently attracted attention as a photoconductive conversion material, and is being actively applied to solar cells, 1llI transistors, and image sensors. As part of this application of a-3i, attempts have been made to use a-8i as a photoconductive material for electrophotographic photoreceptors, and photoreceptors using a-3i are recycled because they are non-polluting materials. It has advantages such as no need for treatment, higher spectral sensitivity in the visible light region than other materials, high surface hardness, and excellent wear resistance and impact resistance.

This a-8: is being studied as a photoreceptor based on the Carlson method, but in this case, the photoreceptor characteristics are required to be high resistance and photosensitivity. Because it is difficult to satisfy the photoreceptor of the light guide! A blocking layer was provided between the i-layer and the conductive support, and a surface charge retention layer was provided on the photoconductive layer! These requirements are satisfied by adopting a one-layer structure.

By the way, a-3i is usually a glow ti! that uses silane gas. It is formed by the i1 decomposition method, but at this time hydrogen is incorporated into a-8iPIA, and the electrical and optical properties vary greatly depending on the difference in hydrogen seedlings. That is, a
When the amount of hydrogen that permeates into -8il increases, the optical bandgap increases and the resistance of a-8i increases, but this also reduces the photosensitivity to long wavelength light, so for example, semiconductor lasers It is difficult to use with laser beam printers equipped with Also, a-
When the hydrogen content in the 3i film is high, depending on the film forming conditions, those having bonding structures such as (SiH2)n and SiH2 may occupy most of the area in the film. In this case, voids increase and silicon dangling bonds increase, resulting in deterioration of photoconductive properties and rendering the material unusable as an electrophotographic photoreceptor. Conversely, reducing the amount of hydrogen penetrating into a-8i reduces the optical band gap and its resistance, but increases photosensitivity to long wavelength light. However, when the hydrogen content is low, there is less hydrogen to combine with and reduce silicon dangling bonds. For this reason, the mobility of the generated carriers is reduced, the life span is shortened, and the photoconductive properties are deteriorated, making it difficult to use as an electrophotographic photoreceptor.

In addition, as a technique to increase the sensitivity to long wavelength light, there is a method of mixing silane-based gas and germane GeH4 and performing glow discharge decomposition to produce a film with a narrow optical band gap.In general, however, silane-based gas Since the optimum substrate temperature is different between GeH+ and GeH+, the produced film has many structural defects and cannot obtain good photoconductive properties. Furthermore, waste gas treatment is complicated because GeH+ waste gas becomes toxic gas when oxidized. Therefore, such technology is not practical.

The present invention has been made in view of the above circumstances, and provides an electrophotographic photoreceptor that has excellent charging ability, low residual potential, high sensitivity over a wide wavelength range, and excellent environmental resistance. The purpose is to

[Means for Solving the Problems] An electrophotographic photoreceptor according to the present invention includes an electrically conductive support and a photoconductive layer formed on the electrically conductive support. In the photoconductive layer, a first amorphous silicon layer, a microphone, locrystalline silicon layer, and a second amorphous silicon layer are sequentially laminated from the conductive support side, and the second amorphous silicon layer In the first amorphous silicon layer, at least one kind of atoms selected from carbon, nitrogen, and oxygen forms a non-uniform concentration distribution in the layer thickness direction, and the first amorphous silicon layer has at least one kind of atoms selected from carbon, nitrogen, and oxygen. having a first region and a second region containing at least one or more atoms selected from at least one kind of atoms selected from oxygen;
The first region has photoconductivity, the concentration of the atoms in the first region is higher than IIrx in the second region, and the concentration distribution in the first region changes non-uniformly in the layer thickness direction. It is characterized by

The present inventor has developed an electrophotographic photoreceptor according to the present invention in order to overcome the drawbacks of the prior art described above and to develop an electrophotographic photoreceptor that has both excellent photoconductive properties (single-child photographic properties) and environmental resistance. As a result of various experimental studies, they found that this objective could be achieved by making part or all of the photoconductive layer consist of microcrystalline as a seed, or by making it a laminate of amorphous silicon and microcrystalline silicon. This invention was completed after coming up with the idea that this could be done.

This invention will be specifically explained below.

This invention includes amorphous silicon (hereinafter referred to as a-8i) or microcrystalline silicon (hereinafter referred to as μC-8i).
8i) is used. μC-3i is clearly distinguished from a-3i and polycrystalline silicon (polycrystalline silicon) by the following physical characteristics. That is, in X-ray diffraction measurements, since a-3i is amorphous, only a halo appears and no diffraction pattern can be observed, but μC-3i has a 2θ of around 27 to 28.5°. The crystal diffraction pattern is shown. Also,
Polycrystalline silicon has a dark resistance of 10"Ω·cm, whereas μC-8i has a dark resistance of 10"Ω·α or more.

This μC-S + is formed by aggregation of microcrystals having a particle size of approximately several tens of angstroms or more.

Similar to a-3i, such a μC-8i layer can be manufactured by depositing μC-8i on a conductive support using silane gas as a raw material by a high frequency glow discharge decomposition method. In this case, the temperature of the support is set to a-8
It is set higher than when forming i, and the high frequency power is also a-
If it is set higher than in the case of 3i, it becomes easier to form μC-8i. Furthermore, by increasing the support temperature and high frequency power, the flow rate of source gas such as silane gas can be increased, and as a result, the film formation rate can be increased. Further, by using a gas obtained by diluting SiH4 and a high-order silane gas such as 5i2Hs as a raw material gas with hydrogen, μC-8i can be formed with higher efficiency.

FIG. 1 is a diagram showing an apparatus for manufacturing an electrophotographic photoreceptor according to the present invention. The gas cylinders 1.2° and 3.4 are filled with, for example, SiH+ and B2 Hs, respectively.

Source gases such as H2 and CH4 are contained. The gas in these gas cylinders 1.2.3.4 is supplied to a mixer 8 via a flow rate adjustment valve 6 and piping 7. Each cylinder is equipped with a pressure gauge 5, and by monitoring the pressure gauge 5 and adjusting the valve 6, the flow rate and mixing ratio of each raw material gas supplied to the mixer 8 can be adjusted. can. The gases mixed in the mixer 8 are supplied to a reaction vessel 9. A rotating shaft 10 is attached to the bottom 11 of the reaction vessel 9 so as to be rotatable around the vertical direction, and a disk-shaped support 12 is attached to the upper end of the rotating shaft 10 with its surface perpendicular to the rotating shaft 10. It has been fixed. Inside the reaction vessel 9, a cylindrical electrode 13 is installed on the bottom 11 with its axial center aligned with the axial center of the rotating shaft 10.

A drum base 14 of a photoreceptor is placed on a support base 12 with its axial center aligned with the axial center of the rotating shaft 1o, and a heater 15 for heating the drum base is arranged inside the drum base 14. It is set up. A high frequency power source 16 is connected between the nozzle 13 and the drum base 14, and a high frequency current is supplied to the electrode 13 and the drum base 14B. The rotating shaft 10 is rotationally driven by a motor 18. The pressure inside the reaction vessel 9 is monitored by a pressure gauge 17, and the reaction volume B9 is connected via a gate valve 18 to an appropriate evacuation means such as a vacuum pump.

When manufacturing a photoreceptor using an apparatus configured as described above, after installing the drum base 14 in the reaction vessel 9, the gate pulp 19 is opened to control the inside of the reaction vessel 9 at approximately 0.1 Torr. Evacuate to below pressure. Next, cylinder 1
, 2.3.4, the required reaction gases are mixed at a predetermined mixing ratio and introduced into the reaction vessel 9. Next, the motor 18 is operated to rotate the drum base 14, the heater 15 heats the drum base 14 to a constant temperature, and the high frequency electric current 116 supplies a high frequency current between the electrode 13 and the drum base 14. A glow discharge is formed between the two. As a result, μC-8i is deposited on the drum base 14. Note that N20. NH3, NO2, N2, C
l-14.

These atoms can be contained in μC-Sr by using C2H4,02 gas or the like.

In this way, the electrophotographic photoreceptor according to the present invention has a conventional a
Similar to those using -3i, it can be manufactured using the manufacturing equipment of the Rised System, and is therefore safe for the human body. Furthermore, this electrophotographic photoreceptor has excellent heat resistance, moisture resistance, and abrasion resistance, so it has the advantage of having a long lifespan with little deterioration even after repeated use over a long period of time. Furthermore, since a long wavelength sensitizing gas such as GeH4 is not required, there is no need to provide waste gas treatment equipment, and industrial productivity is significantly improved.

It is preferable that μC-8i contains 0.1 to 30 at % of hydrogen. As a result, the dark resistance and bright resistance become harmonious, and the photoconductive properties are improved. μC-
The optical energy gap Ea of 8i is the optical energy gap Ea of a-8i (1,65 to 1.70 eV
) is small compared to In other words, the optical energy gap of μC-8i changes depending on the grain size and crystallinity of the μC-sr microcrystal, and as the grain size and crystallinity increase, the optical energy gap decreases. , approaches the optical energy gap of crystalline silicon, 1.18V. By the way, the μc-3il and a-S'i layers absorb light with a larger energy than this optical energy gap, and transmit light with a smaller energy. For this reason, a-8i
absorbs only visible light energy, but μc-sr, which has a smaller optical energy gap than a-3i, can even absorb near-infrared light, which has a longer wavelength and lower energy than visible light. Therefore, μC-S t has high photosensitivity over a wide wavelength range.

μc-s i having such characteristics is suitable as a photoreceptor material for a laser printer using a semiconductor laser as a light source. When a-8i is used as a photoconductor for a laser printer, the light wavelength of the semiconductor laser is 790 nm, which is 790 nm.
Since i is longer than the wavelength range in which it is highly sensitive, the sensitivity of the photoreceptor becomes insufficient, and therefore it is necessary to apply a laser intensity to the photoreceptor that exceeds the ability of the semiconductor laser, which is a practical problem. On the other hand, when a photoreceptor is formed using μC-SR, its high sensitivity region extends to the near-infrared region, so it is possible to obtain a photoreceptor for semiconductor laser printers with extremely excellent photosensitivity characteristics. .

In order to further improve the photoconductive properties of μC-8i, which has such excellent photosensitivity characteristics, μC
-8i preferably contains hydrogen.

Hydrogen doping to μC-81m is carried out, for example, by glow electrolysis, using Si+-1+ and 5i2Hs.
Either a silane-based source gas such as S t F and a carrier gas such as hydrogen are introduced into the reaction vessel to cause glow discharge,
A mixed gas of a silicon halide such as 4 and 5iC1+ and hydrogen gas may be used, or a mixed gas of a silane gas and a silicon halide may be used.

Furthermore, the μC-8i layer can be formed not only by the glow discharge decomposition method but also by a physical method such as sputtering. Note that the photoconductive layer containing μC-8i preferably has a thickness of 1 to 80 μm in terms of photoconductive properties.
Furthermore, it is desirable that the film thickness be 5 to 50 μm.

Substantially the entire region of the photoconductive layer may be formed of μC-8i, or may be formed of a mixture or a laminate of a-8i and μC-8i. The charging ability is higher in the laminate, and the photosensitivity is higher in the long wavelength region of the infrared region, although it depends on the volume ratio, in the mixture, and in the visible light region, the two are almost the same.

Therefore, depending on the use of the photoreceptor, substantially all the regions may be made of μC-8i, or may be made of a mixture or a laminate.

Preferably, μC-8i is doped with at least one type of atom selected from nitrogen, N, carbon, and oxygen. Thereby, the dark resistance of μC-8i can be increased and the photoconductive properties can be improved.

These atoms precipitate at the grain boundaries of μC-8i and act as terminators for silicon dangling bonds,
It is thought that the density of states existing in the forbidden band between bands is reduced, thereby increasing the dark resistance.

A blocking layer may be provided between the conductive support and the photoconductive layer. This blocking layer suppresses the flow of charge between the conductive support and the photoconductive layer, thereby increasing the charge retention function on the surface of the photoconductive member and increasing the charging ability of the photoconductive member. . In the Carlson method, when the surface of the photoreceptor is positively charged, the blocking layer is made p-type in order to prevent electrons from being injected from the support side to the photoconductive layer. On the other hand, when the surface of the photoreceptor is negatively charged, the blocking layer is made of n-type in order to prevent holes from being injected from the support steel into the photoconductive layer. It is also possible to form an insulating film on the support as a blocking layer. The blocking layer may be formed using μC-8i, or it may be formed using a-8i.

In order to make μC-8i and a-8i p-type, it is preferable to dope them with atoms belonging to Group Ⅰ of the periodic table, such as boron B, aluminum AI, gallium Ga, indium In1, and thallium T1. , μC-8i
In order to make the layer n-type, atoms belonging to group V of the periodic table, such as nitrogen N, phosphorus P, arsenic As, and antimony S, must be added.
It is preferable to dope with B, bismuth Bi, or the like.

This doping with p-type impurities or n-type impurities prevents charges from moving from the support side to the photoconductive layer.

A surface layer may be provided on top of the leading M layer. μC of photoconductive layer
-8i has a relatively large refractive index of 3 to 4, so
Light reflection on the surface is likely to occur. When such light reflection occurs, the proportion of the amount of light absorbed by the photoconductive layer decreases, increasing optical loss.

For this reason, it is preferable to provide a surface layer to prevent reflection. Also, by providing the surface layer, the photoconductive layer is protected from scratches. Furthermore, by forming the surface layer, the charging ability is improved, and the charge can be easily deposited on the surface.

The material forming the surface layer is Si3N4.5i02
, SiC.

Al1 03, a-8iN:H, a-8iO:H.

and a-8iC:H, and organic materials such as polyvinyl chloride and polyamide.

As mentioned above, electrophotographic photoreceptors are not limited to those in which a photoconductive layer is formed on a support, but also those in which a charge transfer layer (C) is formed on a support.
A charge generation layer (CGL) is formed on the charge transfer layer.
) can also be constructed in a functionally separated form. In this case, a blocking layer may be provided between the charge transfer layer and the support. The charge generation layer generates carriers upon irradiation with light. The charge generation layer is preferably made of μC-S+ or a-8i in part or in its entirety, and has a thickness of 0.1 to 10 μm. The charge transfer layer is a layer that allows carriers generated in the charge generation layer to reach the support side with high efficiency, and because of this, it is necessary that the carriers have a long life, have high mobility, and have high transportability. The charge transfer layer can be formed of a-3i. In order to reduce dark resistance and improve charging ability,
It is preferable to light-dope atoms belonging to either group or group (IV). Furthermore, in order to further improve the charging ability and to have the functions of both a charge transfer layer and a charge generation layer, one or more of C, N, and O atoms may be contained. If the charge transport layer is too thin or too thick, it will not perform its function satisfactorily. Therefore, the thickness of the charge transport layer is preferably 3 to 80 μm.

By providing a blocking layer, even in a functionally separated photoreceptor having a charge transfer layer and a charge generation layer, its charge retention function and charging ability can be improved. Note that whether the blocking layer is p-type or n-type is determined depending on its charging characteristics. This blocking layer may be formed of a-8i or μC-S
It may be formed by +.

The feature of the invention according to this application is that the photoconductive layer includes a first amorphous silicon layer, a microcrystalline silicon layer, and a second amorphous silicon layer stacked in order from the conductive support side, In the second amorphous silicon layer, at least one kind of atoms selected from carbon, nitrogen, and oxygen forms a non-uniform concentration distribution in the layer thickness direction, and the first amorphous silicon layer has a conductivity type that is dominant. a first region and a second region containing at least one or more atoms selected from carbon, nitrogen, and oxygen;
The first region has photoconductivity, the concentration of the atoms in the first region is higher than the concentration in the second region, and the concentration distribution in the first region changes non-uniformly in the layer thickness direction. It is in the fact that

[Example] Next, the structure of the layers of an electrophotographic photoreceptor embodying the present invention will be described with reference to FIG.

In the electrophotographic photoreceptor shown in FIG. 2, a leading N layer 103 is laminated on an aluminum conductive support 101. The photoconductive layer 103 includes, in order from the support 101 side, an 8-3i layer 106 of the tube 1, an ac-8i layer 104,
The second (7) a-8i 1105 is laminated. This second a-8i layer 105 contains at least one of CSO and N atoms. 1st a-8
The i-layer 106 contains atoms that control the conductivity type, as well as C and O.

At least one atom of N is contained. This first a-8i layer 106 has photoconductivity and the support 1
01, and a second region 108 formed on the first region 107. The concentration of the atoms controlling the conductivity type and at least one or more atoms of C10 and N contained in the first region 107 is higher than that of 8IrIJ in the second region,
Moreover, it is distributed non-uniformly in the layer thickness direction.

According to the electrophotographic photoreceptor of the present invention, the photoconductive layer 103 includes the photoconductive first a-3i layer 1 sequentially from the support 101.
06, μc-s r layer 104, and second a-8i layer 1
They are stacked in the order of 05.

Although the μC-8i layer 104 has excellent long wavelength sensitivity, it has a drawback of low dark resistance. However, according to the structure of such an electrophotographic photoreceptor, this μC-8i layer 104 is
-3 is sandwiched between the second region 108 of layer 106 and the second a-8i layer 105 to compensate for the low dark resistance of the μC-8i layer 104. Therefore, when this electrophotographic photoreceptor is irradiated with light around visible light, the second area 108 and μ
C-8i) 1104 is absorbed. In addition, when irradiated with long wavelength light such as a semiconductor laser, μC-8i
Layer 104 can absorb most of it.

If only a-5i is used as a photoconductive layer,
The sensitivity is high near visible light, and the photosensitivity drops sharply to light with a wavelength near infrared rays, which is normally used in laser printers, resulting in image fogging, fogging, fading, uneven density distribution of images due to buffering, etc. There is an inconvenience that defects occur. However, according to the electrophotographic photoreceptor of the present invention, as described above, the μC-8i layer 104 is provided between the second region 108 of the second A-8i layer 105 and the first A-8i layer 106. This allows it to absorb light of a wide range of wavelengths, resulting in clear images.

When the electrophotographic photoreceptor is charged, the second a-3i
The layer 105 retains a charge on its free surface side, and then when irradiated with light, the second layer 105 of the first a-3i layer 106
Optical carriers are generated in the region 10B and μC-81) 1104. The generated optical carriers are instantaneously transported and neutralize the charges held on the free surface side of the second amorphous silicon III 05. In this case, the second a-3i
Since the layer 105 contains at least one of C10 and N atoms, the non-photoconductivity is increased and the charging ability is improved.

The first region 107 of the first a-8i layer 106 includes C1
Since at least one atom of 0 and N atoms is contained, it is possible to prevent charges from flowing from the support 101 toward the second a-8i layer 105.

Each of the first region 107 of the first a-8i layer 106 and the second a-8i layer 105 contains at least one atom of C10 and N, and the concentration of this content is The distribution is non-uniform in the layer pressure direction. In this case, peeling of the layer or occurrence of cracks can be prevented, and furthermore,
Since trapping of the carrier is prevented, blurring or blurring of the image can be prevented. If the concentration distribution of the inclusions is constant in the layer pressure direction, if a layer with a relatively large optical band gap is formed in this layer, there will be a problem of poor adhesion between these two layers after film formation. There is. As a result, the adhesion between the two layers is poor and peeling or cracking occurs. Or, because the characteristics of the two layers are different, carriers may be trapped between these layers, causing the image to blur or flow.

According to this invention, it is highly sensitive to light with wavelengths from visible light to near infrared rays, so it is highly sensitive to long wavelength light, and can be used as a photoreceptor for laser printers. A photoreceptor with high resolution, high cost, and excellent charging ability can be provided.

Next, embodiments of the invention will be described.

Example 1 An AI drum (diameter: 80 mm, length: 350 mm) serving as a conductive substrate was degreased with trichlene, washed and dried, and then loaded into a reaction vessel. The surface of this drum is subjected to acid treatment, alkali treatment, or sandblasting treatment as necessary to prevent interference. Drum base 101
is heated and held at approximately 320°C. Next, B2 Hs gas with a flow rate ratio of 5X10' to the SiH+ gas flow rate,
A mixture of 25% CH4 gas and 70% H2 gas was supplied to the reaction vessel. Thereafter, the inside of the reaction vessel was evacuated using a mechanical booster pump and a rotary pump, and the reaction pressure was adjusted to 0.6 Tor. motor 18
While rotating the base 14, a high frequency power of 200 W (watts) was applied to the electrode to generate plasma (glow discharge) between the electrode and the drum base to form a film. During film formation, the flow rates of B2Ha and CH4 gas were gradually reduced,
Finally CH4 gas 0.5%, 82 H6 gas 10=
lowered to Under these conditions, film formation was continued for about 45 minutes to form a first region 107 of the first a-8i layer 106 with a thickness of 4 μm on the support 101.

After the film formation of the first region 107 was completed, 0.5% of CH4 gas and 82 H6 gas were supplied at 10-7 with respect to the SiH+ gas flow rate. The film was formed under these conditions for 25 minutes to form the second region 108 of the first a-8i layer 106 with a film thickness of 2 μm.

After forming the first a-3i layer 106, H2 gas was supplied to the S i H4 gas stream at a ratio of 10 times, the reaction pressure was 1.2 Torr, and a high frequency electric cuff of 50 W (watts) was applied for 6 hours. Film formation was continued to form a μC-8i layer 104 having a thickness of 15 μm, a crystal grain size of 35, and a crystallinity of 65%.

Next, increase the N2 gas to 30% of the S i H4 gas flow rate.
The reaction pressure was 0.6 Torr, and high frequency power of 300 W was applied to start discharge. During film formation, N2
Continue to gradually increase the supply amount of N2 gas and increase the flow rate of N2 gas to 600%.
The film was formed for 30 minutes. In this way, 3μ
m second a-3i layer 105 was formed.

Stop" port 1 In the above-mentioned Example 1, the first a-3i111106
The first area 107 of
The film was formed for 30 minutes. After that, the second a-3i layer 105
was deposited. That is, in this comparative example, all layers were formed only from the a-3i layer without forming μC-8il. Incidentally, the total film thickness of this comparative example was 24 μm.

A comparative experiment was conducted on the photoreceptors of Example 1 and Comparative Example formed as described above. When a voltage of 6.5 KV (kilovolts) was applied to each photoreceptor, the surface potential of Example 1 was 5.
The retention rate at 50V for 15 seconds was 60%. On the other hand, the surface potential of the comparative example was 400V, and the retention rate for 115 seconds was 30%.

Further, as shown in the graph of FIG. 3, the photosensitivity to wavelength of each photoreceptor in this example and comparative example was measured.

In FIG. 3, the horizontal axis represents the wavelength of light (nm), and the vertical axis represents the sensitivity (cm/erg), and the sensitivity at multiple wavelengths of light was measured. In this graph, the solid line shows the measurement results of Example 1, and the broken line shows the measurement results of the photoreceptor of Comparative Example. As is clear from this graph, according to this Example 1,
Compared to the conventional method, it was possible to obtain good sensitivity for light in a long wavelength region of about 700 to 800 nm.

Next, each photoreceptor was attached to a laser printer, an image was formed by the laser printer, and the images were compared. In this case, in Example 1, a clear image with high resolution and high contrast was obtained, but in Comparative Example, fog and MIj
Image defects such as uneven image density due to stripes occurred.

fi In Example 1, electrophotographic photoreceptors were formed by varying the flow rate ratio of CH4 gas to SiH4 gas. The film was formed under the same conditions as in Example 1 in other respects, and the concentration of carbon C added was non-uniformly distributed in the layer thickness direction. The layer thickness in this case and CH4 for 5i84 gas flow rate
The relationship with the gas flow rate ratio is shown in the graphs for the fourth to twelfth factors. 4 to 12, the horizontal axis shows the flow rate ratio of gas containing at least one of C10 and N atoms, the vertical axis shows the layer thickness, and the solid line shows at least one of CSO and N atoms. The flow rate of a gas containing one of the above and the broken line indicates a gas containing an atom of group Ⅰ or group V of the periodic table.

In any of these graphs, the concentration of atoms contained in each gas is non-uniform in the thickness direction of the layer. In the case of this Example 2, the same effects as in Example 1 could be obtained.

N2 gas was supplied in place of the CH4 gas supplied in LLL Support Example 2. That is, nitrogen N was added to the electrophotographic photoreceptor, and its concentration was made non-uniform in the film thickness direction. In the electrophotographic photoreceptor according to the third example, similar results to those of the first example could be obtained.

[Effect of the invention] .

According to the present invention, it is possible to obtain an electrophotographic photoreceptor that has high resistance and excellent charging characteristics, has high photosensitivity characteristics in the visible light and near infrared light regions, is easy to manufacture, and is highly practical. I can do it.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a manufacturing apparatus for an electrophotographic photoreceptor according to the present invention, FIG. 2 is a sectional view showing an electrophotographic photoreceptor according to an embodiment of the invention, and FIG. 3 is a diagram showing the relationship between the wavelength of light and the sensitivity. Graphs showing the relationship, Figures 4 to 12, show the relationship between the layer thickness when forming a layer, the gas flow ports of C10 and N, and the supply amount of gas containing atoms of Groups I and V of the periodic table. It is an Arab diagram showing the relationship between the two. 1.2.3.4: Cylinder, 5; Pressure gauge, 6; Valve, 7
; Piping, 8; Mixer, 9: Reaction container, 10; Rotating shaft, 1
3; Electric vapor, 14; Drum base, 15; Heater, 16; High frequency N source, 19; Gate valve, 101; Support, 10
3; photoconductive layer, 104: microcrystalline silicon layer, 105; second amorphous silicon layer, 106;
first amorphous silicon layer, 107; first region;
108: 2nd (7) ffa area. Applicant's representative Patent attorney Takehiko Suzue Figure A34 Figure S5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Showa year
Director of the Patent Office Michibe Uga 1, Indication of the case Japanese Patent Application No. 60-256062 2, Name of the invention Electrophotographic photoreceptor 3, Annex IV-, Relationship with the case Patent applicant (307) Toshiba Corporation 4, agent ('1 force, 1 person) 6 Specification subject to oil stop -1-1-11' G7.
:, I ++] 7. Contents of the amendment (the scope of the claim is revised as shown in the attached sheet). (2) In the specification, page 7, lines 12 and 13, page 20, line 7 In lines 8 through 8, the words "at least one or more of at least one type of atoms" should be corrected to "at least one type of atom." (3) In the specification, page 7, line 14 No. 9, page 20
In the second line, ``the first m area'' is corrected to ``the second area''. (4) In the specification, on page 8, line 3, the word ``seed'' should be changed to ``main''. (5) In the specification, page 22, line 14, page 28, line 10
In the second row, the words "buffer fringes" are corrected to "interference fringes." (6) In the specification, page 24, line 1, page 24, line 5
2゜(7) In the specification, on page 25, line 12, "TO" should be corrected from "layer pressure" to "layer thickness."
" is corrected to l'-Torrj. (8) In the specification, page 30, line 9, “bluff”
Correct the word "graph" to "graph". 2. Claims (1) In an electrophotographic photoreceptor comprising an electrically conductive support and a photoconductive layer formed on the electrically conductive support, the photoconductive layer has a surface on the electrically conductive support side. A first amorphous silicon layer, a microcrystalline silicon layer, and a second amorphous silicon layer are sequentially stacked, and the second amorphous silicon layer includes carbon,
At least one type of atom selected from nitrogen and oxygen forms a non-uniform concentration distribution in the layer thickness direction, and the first amorphous silicon layer includes atoms that dominate the conductivity type and atoms selected from carbon, nitrogen and oxygen. a first region and a second region containing at least one kind of atom, the second region having photoconductivity and a concentration of the atoms contained in the first region being a second region; The concentration in the area is also high,
An electrophotographic photoreceptor characterized in that the concentration distribution in the first region changes non-uniformly in the layer thickness direction. (2) The microcrystalline silicon layer and the second amorphous silicon layer are arranged in groups Xia and V of the periodic table.
The electrophotographic photoreceptor according to claim 1, characterized in that the electrophotographic photoreceptor contains at least one type of atom selected from the group consisting of:

Claims (2)

[Claims] (1) In an electrophotographic photoreceptor having a conductive support and a photoconductive layer formed on the conductive support, the photoconductive layer includes a first amorphous layer formed from the conductive support side. A silicon layer, a microcrystalline silicon layer, and a second amorphous silicon layer are sequentially stacked, and the second amorphous silicon layer includes carbon,
At least one type of atom selected from nitrogen and oxygen forms a non-uniform concentration distribution in the layer thickness direction, and the first amorphous silicon layer includes atoms that dominate the conductivity type and atoms selected from carbon, nitrogen and oxygen. a first region and a second region containing at least one kind of atoms, the first region having photoconductivity and the atoms contained in the first region; An electrophotographic photoreceptor characterized in that the concentration of the first region is higher than that of the second region, and the concentration distribution of the first region changes non-uniformly in the layer thickness direction. (2) The microcrystalline silicon layer and the second amorphous silicon layer are made from Group III and Group III of the periodic table.
The electrophotographic photoreceptor according to claim 1, which contains at least one type of atom selected from Group IV.