JPS6330855A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having high electric chargeability by forming an a-SiC:H film as a carrier transferring layer, an a-SiC film as a carrier injection preventive layer and an a-SiGeC film as a carrier generating layer under various conditions. CONSTITUTION:A carrier injection preventive layer 5, a carrier transferring layer 2a and a carrier generating layer 3a are formed on a substrate 1 to obtain a laminated body. The layer 5 is made of a-SiC having 1:9-9:1 atomic ratio of C:Si and the layer 3a is made of amorphous silicon germanium carbide (a- SiGeC) having 1:1-19:1 atomic ratio of Si:Ge and 1:1-19:1 atomic ratio of Si:C. The layer 2a is made of a-SiC:H having 1:9-9:1 atomic ratio of C:Si, <=1,000 absorption coefft. at 2,860cm<-1> in the infrared absorption spectrum and >=1,000 absorption coefft. at 2,090cm<-1>. The dark attenuation rate of the resulting sensitive body is reduced and the electric chargeability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor that is suitable for a laser beam printer using a semiconductor laser and enables high-speed copying by improving charging ability.

[Prior art and its problems]

In recent years, electrophotographic photoreceptors have made tremendous progress, and the development of ultra-high-speed copying machines and laser beam printers is actively underway.The photoreceptors used in these devices are used at high speeds for long periods of time, so Operational stability and durability are required. In response to this demand, hydrogenated amorphous silicon is attracting attention because it has excellent heat resistance, wear resistance, non-pollution properties, and photosensitivity characteristics.

In addition, with the development of laser beam printers capable of high-speed printing, compact and highly reliable semiconductor lasers have come to be used as laser light sources. ) When a photoreceptor is mounted, there is a problem in that the oscillation wavelength of this laser light is in the vicinity of near infrared rays, so that the a-St photoreceptor on the light receiving side has poor photosensitivity characteristics. In order to solve this problem, it has been proposed to dope the a-Si carrier generation layer of the photoreceptor with an appropriate amount of Ge to shift the photosensitivity region of this layer to the longer wavelength side. There was a problem that the potential became small.

In order to solve this problem, a functionally separated type photoreceptor as shown in FIG. 2 has been proposed in Japanese Patent Application Laid-open No. 192044/1983.

That is, according to FIG. 2, a carrier transport layer (2) made of hydrogenated amorphous silicon carbide, a carrier generation layer (3) made of amorphous silicon germanium, and a surface protection layer (4) are formed on a conductive substrate (1). has been proposed, and the carrier transport layer (2) is made of hydrogenated amorphous silicon carbide (hereinafter referred to as a-3iC:H), which can be a material with high dark resistivity and carrier mobility. ) is formed by
The aim is to achieve excellent surface potential and photosensitivity, and to have a small residual potential.

However, when forming the a-5iC:H carrier transport layer disclosed in this publication, for example, when using the glow discharge decomposition method, various discharge conditions such as reaction pressure, high frequency power, type of raw material gas, gas flow rate etc. Due to these reasons, it is difficult to form a high-quality a-3iC:H film with stable characteristics, and this film itself is more difficult to form than a hydrogenated amorphous silicon (hereinafter abbreviated as a-Si:H) film. Dangling bonds tend to form easily, which makes it difficult to obtain an a-SiC:H film that has a high dark resistivity of 10 Ωcm or more as a guide and high carrier mobility. As a result, when this photoreceptor is used for high-speed copying, there is a problem that the previous image remains without being completely removed due to the optical memory effect, and the previous image reappears when the next image is formed. (This is called the ghost phenomenon).

Furthermore, in order to form this a-5iC:H film under stable conditions with good reproducibility, there is a need for a detection means that can commonly evaluate the characteristics of both dark resistivity and carrier mobility.

In addition, when forming a carrier generation layer containing Ge, stable adhesion to the carrier transport layer is not obtained, and some peeling may occur depending on discharge conditions such as gas pressure and high frequency power. There is a problem in that this becomes a pinhole and causes white spots in the image.

[Purpose of the invention]

Therefore, the present invention was completed in view of the above circumstances, and its purpose is to improve the dark resistivity and carrier mobility of the a-3iC:H carrier transport layer, thereby producing an electrophotographic photosensitive material with large charging ability. It's about offering your body.

Another object of the present invention is to provide an electrophotographic photoreceptor for semiconductor laser beam printers capable of high-speed copying and high-speed printing.

Still another object of the present invention is to provide an electrophotographic photoreceptor in which manufacturing conditions for manufacturing an a-5iC:H carrier transport layer are easy to set, and the reproducibility and stability are excellent.

Still another object of the present invention is to increase the adhesion of the carrier generation layer to the base layer to prevent the generation of pinholes, thereby preventing white spots and the like from occurring in images over a long period of time (resulting in high image quality and An object of the present invention is to provide an electrophotographic photoreceptor that achieves high photoconductivity.

[Means for solving problems]

According to the present invention, there is provided a laminate comprising at least a carrier injection blocking layer, a carrier transport layer, and a carrier generation layer formed on a substrate, the carrier injection blocking layer being a-SiC.
and the atomic composition ratio of C and Si is 1:9 to 9:
1, and the carrier generation layer is made of amorphous silicon germanium carbide (hereinafter, a-3iGe
(abbreviated as C), and the atomic composition ratio of Si and Ge is 1.
:1 to 19:1 and the atomic composition ratio of Si and C is within the range of 1:1 to 19:1, and the carrier transport layer is composed of a-5iC:H and the atomic composition of C and Si is in the range of 1:1 to 19:1. The ratio is within the range of 1:9 to 9:1 and the absorption coefficient at 2860 cm-' in the infrared absorption spectrum is 100.
0 or less and the absorption coefficient at 2090 cm-' is 10
Provided is an electrophotographic photoreceptor characterized in that it has a molecular weight of 0.00 or more.

The present invention will be explained in detail below.

As shown in FIG. 1, a typical electrophotographic photoreceptor of the present invention includes a carrier injection blocking layer (5), a carrier transport layer (2a), a carrier generation layer (3a) and a surface protection layer (1i) on a substrate (1). There is a laminate in which 4a) are sequentially laminated, and there is also a laminate in which the carrier transport layer ii (2a) and the carrier generation layer (3a) are stacked in a different order.

According to the present invention, the a-5iC:H film and the a-5iC film are used for the carrier transport layer (2a) and the carrier injection blocking layer (5) used in the functionally separated photoreceptor, respectively, and the carrier generation Jil (3a) is used. It has been discovered that the object of the present invention can be achieved by using a-5iGeC films and setting various conditions for these layers.

The a-SiC:H film used for this carrier transport layer is
For example, the dark resistivity and carrier mobility are generated by the glow discharge decomposition method described below, and the dark resistivity and carrier mobility are sensitively affected by the discharge conditions. As a result of repeated experiments, C
It has been found that the bonding state between Si and H and the bonding state between Si and H significantly affect the above characteristics.

That is, when measuring the infrared absorption spectrum of the a-5iC:H film, an absorption peak indicating the stretching mode of CH, bond, and CH3 bond appears at a wave number of 2860 cm-', and an absorption peak indicating the stretching mode of SiH bond and 5jHz bond. is 2
The absorption coefficient at 2860 cm-' is 1000 or less, the absorption coefficient at 2090 cm-' is 1000 or more, and preferably the absorption coefficient at 2860 cm-' is 500 or less. It was found that if the absorption coefficient at 2090 cm-' is 1000 or more, the number of dangling bonds decreases and the carrier mobility becomes large.

Note that the absorption coefficient value expressed in the present invention is expressed in units of cm"', which are commonly used by those skilled in the art.

According to the present invention, the atomic composition ratio of St and C in this a-5iC:H film is important, and this ratio is 1:9 to 9:1,
It has been found that when the ratio is preferably set within the range of 2:8 to 8:2, the dark resistivity becomes 10'1 Ω·cm or more.

Further, the hydrogen content in the film is related to the 5i-C atomic composition ratio, but it may be within the range of 5 to 40 atomic %, preferably 10 to 30 atomic %.

The thickness of this carrier transport layer is preferably set within the range of 1 to 50 μm1, preferably 5 to 30 μm.If it is less than 1 μm, the charge retention ability will be poor and the ghost phenomenon will become noticeable, and if it exceeds 50 μm, the image will deteriorate. As the resolution deteriorates, the residual potential increases.

Further, although this carrier transport layer requires three types of atoms, St, C, and H, there is no problem in doping with other atoms as necessary. For example, doping with a group MA element of the periodic table such as B can improve dark resistivity and increase carrier mobility.
Furthermore, since the Fermi level at the interface between the carrier generation layer and the carrier transport layer can be shifted, the photocarriers generated in the carrier generation layer can be smoothly injected into the carrier transport layer, thereby increasing photosensitivity. Residual potential can be reduced.

Since the carrier generation layer (3a) used in the present invention is made of a layer containing Ge, the spectral sensitivity characteristics are shifted to the longer wavelength side compared to the a-3i layer. This layer (3a) has an atomic composition ratio of Si to Ge of 1:1 to 19:1, preferably 2:1 to 1.
It is important to set the ratio within the range of 0:1, and as a result, the photosensitivity to semiconductor laser light with an oscillation wavelength of about 780 nm is significantly improved compared to a photoreceptor using an a-5i carrier generation layer. . According to experiments conducted by the present inventors, for a functionally separated photoreceptor formed with an a-5iC:H carrier transport layer, the atomic composition ratio of Si and Ge is 2=1 to 5: It is desirable to set it within the range of 1. Within this range, the residual potential becomes small and a photoreceptor with even higher charging ability can be obtained.

Furthermore, this carrier generation layer (3a) contains C, which makes it possible to thicken the adhesion with the underlying layer such as the carrier transport layer (2).
The atomic composition ratio of i and C is 1:1 to 19:1, preferably 2.
:1 to 10:1, and if this atomic composition ratio deviates from 1=1, the photosensitivity characteristics on the long wavelength side near 780 nm will decrease, causing a practical problem.
: If the atomic composition ratio deviates from 1, adhesion with the underlying layer cannot be expected.

This carrier generation layer contains 11 and halogen elements (F, CI).

Br, etc.), and this content is preferably 5 to 40 at%, preferably 10 to 30 at%. Chapter Va
Group elements (P, As, Sb, etc.) from 0.05 to 500
It is sufficient to contain 0 ppm, preferably 0.1 to 2000 ppm, and thereby the conductivity type of the film can be compensated or the dark resistance value can be increased, and as a result, excellent charging ability can be obtained.

a-SiC carrier injection blocking layer (5
) prevents carrier injection into the carrier transport layer (2a), thereby increasing the surface potential of the photoreceptor. This layer (5) has a content ratio of Si and C of 1
=9 to 9:1, preferably within the range of 2:8 to 8:2; if it is outside this range, dark decay will increase or the residual potential will increase.

Further, this carrier injection blocking layer (5) may contain H or a halogen element (F, CI, Br, etc.), and this content is related to the Si-C atomic composition ratio, but the present inventors According to experiments, the film contains 0.1 to 20 atoms χ, preferably 1
It has been found that it is sufficient to set the value within the range of 1 to 10 atoms χ.

Furthermore, this carrier injection blocking layer (5) is
Group Ia elements (B, AI, Ga, In, etc.) and Va group elements (P, As, Sb, etc.) are introduced into the film to change the conductivity type of the film itself to Po or No, respectively.
It is possible to further prevent the injection of carriers due to the reaction force. Therefore, the content of these group Ma and group Va elements is 50 to 5000 ppm, preferably 200 ppm.
It is preferable to set the amount to 2000 ppm to 2000 ppm.

Further, the carrier injection blocking layer (5) can be doped with at least one of oxygen or nitrogen to further enhance the carrier injection blocking effect, and the doping amount is related to the other constituent elements, but the amount of doping in the film is 0. 1 to 30 atoms χ,
It is preferable to contain 1 to 20 atoms χ.

Furthermore, the thickness of this carrier injection blocking layer (5) is preferably set within the range of 0.2 to 5.0 μm, preferably 0.5 to 3.0 μm, and if the thickness is within this range, the substrate The ability to stop carriers from the inside becomes sufficient, and the residual potential becomes small.

Various materials can be used for the surface protective layer (4a) as long as they themselves have high insulating properties, high corrosion resistance, and high hardness properties. a-3iC and S iOz +
S iO+ A lz Ox + S iC+ S
i 3 N ala −S i +a−5i:H, a−
5t:P+ a-SiC+ a-SiC:)l, a-
Inorganic materials such as SiC:F can be used.

According to the present invention, when forming a carrier injection blocking layer, a carrier transporting layer, a carrier generating layer, and a surface protective layer using the same film forming apparatus, common constituent elements of St and C are used, and the atomic composition ratio of each is increased. It has a remarkable feature in that it can be set within a range, and as a result, when these layers are continuously formed, the same gas flow rate control system using the same Si feed material and C feed material is obtained, and as a result, It becomes easy to control the flow rate of each gas.

Furthermore, according to the present invention, a-5iC film or a-SiC:H
In forming the film, glow discharge decomposition method, ion blating method, reactive sputtering method, vacuum one-piece method,
A thin film forming technique such as a CVD method can be used, and the raw material used therein may be solid, liquid, or gas. For example, 5iHt and 5izH+ are gaseous raw materials used in the glow discharge decomposition method.

, 5i3H, etc., CHa, CzHa,
C-based gases such as C2flz, CzC6°CJs (and H2, He, etc.) may be used.

Ne, Ar, etc. may be used as a carrier gas.

Further, according to the present invention, an a-SiC film or a-SiC:H
If 5if14 gas and C2H2 gas are used as raw materials for forming a film by glow discharge decomposition, a high film formation rate (about 5 to 20 crm/hour) can be obtained. Therefore, using these two gases, the carrier injection blocking layer (5
), by forming the carrier transport layer (2a) and the surface protection layer (4a) with an a-SiC film or an a-3iC:H film, they can be formed continuously using the same film forming apparatus, and the film forming time can be reduced. can be made significantly smaller.

Incidentally, when an a-5rC film or an a-5iC:H film is formed using 5iHa gas and CH4 gas, the film formation rate is approximately 0.
3 to 1 μm/hour.

Next, a capacitively coupled glow discharge decomposition device used in an embodiment of the present invention will be explained with reference to FIG.

In the figure, the first, second, third, fourth, fifth, and sixth tanks (
6) (7) (8) (9) (10)
(11) has 5iHt+CJz+GeHt+, respectively.
BzHi+)Iz+NO gas is sealed, and H2 is also used as a carry gas. These gases correspond to the first. Second. 3rd゜4th. Fifth. 6th tA valve adjustment (1
2) (13) (14) (15) (16) (17
) is released by opening the mass flow controller (1), and the flow rate is controlled by the mass flow controller (1, 1st, 2nd, 3rd).
, 4th and 5th tanks (6) (7) (8) (9) (10)
The gas from the tank goes to the first main pipe (24) and to the sixth tank (1
No gas from 1) is sent to the second main pipe (25). Note that (26) and (27) are stop valves. The gas flowing through the first and second main pipes (24) and (25) is sent to the reaction tube (2nd), and a capacitively coupled discharge electrode (29) is installed inside this reaction tube (28). The appropriate high frequency power applied thereto is 50 W to 3 Kw, and the appropriate frequency is IMH2 to 10 MHz. Inside the reaction tube (28), a cylindrical film-forming substrate (30) made of aluminum is placed on a sample holder (31), and this holder (31) is connected to a motor (32). The substrate (30
) is uniformly heated to a temperature of about 50 to 400°C, preferably about 150 to 300°C, by a suitable heating means.

Furthermore, the interior of the reaction tube (28) is connected to a rotary pump (33) and a diffusion pump (34) since a high degree of vacuum (discharge voltage 0.1 to 2.0 Torr) is required during film formation. .

In the glow discharge decomposition device configured as above,
For example, when forming an a-5iC:H film on the substrate (30) (containing N, O, B), the first and second
, fourth, fifth, and sixth regulating valves (12) (13) (15) (
16) Open (17) and add SiH4 and C2H from each
z, BJ6. Release H2, No gas. The amount of release is determined by the mass flow controller (18) (19) (21) (22)
(23) SiH4, CJz+BzHb
+Hz mixed gas is flowed into the reaction tube (28) through the first main pipe (24), and at the same time, a constant flow rate of No gas is flowed into the reaction tube (28) through the second main pipe (25). Then, the reaction tube (2
8) Inside is in a vacuum state of about 0.1 to 2.0 Torr, and the substrate temperature is 50 to 400°C1 Discharge electrode (29)
Coupled with the high frequency power of 50W to 3KW and the frequency set to 1 to 10MHz, a glow discharge occurs, and the gas decomposes into a-SiC:H containing elements of B, 0, and N. A film is formed on the substrate at high speed.

However, in the Examples described later, when measuring the film formation rate, conductivity, and infrared absorption characteristics of the a-3iC:H carrier transport layer, a 3 x 3 cm rectangular flat plate was prepared, and the aluminum cylindrical substrate described above was used. A part of the circumferential surface of is cut out, a flat plate is installed in this notch, and a is placed on this flat plate.
-3iC:H film is produced. An aluminum plate, a NESA glass plate, and a high-resistance single-crystal silicon plate are used as flat plates for measuring the film formation rate, conductivity, and infrared absorption characteristics, respectively.

〔Example〕

Next, embodiments of the present invention will be described in detail.

[Example 1] In this example, an a-3iC:H carrier transport layer was formed on an aluminum flat plate and its film formation rate was measured.

That is, using the capacitively coupled glow discharge decomposition device shown in Fig. 3, SiH4 gas is supplied from the first tank (6) and Cz) 1m gas is supplied from the second tank (7) at a total flow rate of 2.
70 sec, and if necessary, the fifth
H2 gas was released from the tank (10), an a-SiC:H film was formed based on the glow discharge decomposition method, and the film formation rate was measured, and the results shown in FIG. 4 were obtained.

Figure 4 shows the atomic composition ratio of Si and C in the film (C/Si +
It represents the film formation rate for C), and ○, △ and 0
Each mark indicates that H2 gas is not added and the flow is 1200 sec.
.

This is a plot when the flow rate is 500 sec, and a, b
, c are respective characteristic curves.

As is clear from Fig. 4, when H2 gas is not added, (
The deposition rate tends to increase as the C/Si +C) ratio increases. And the flow rate of H2 gas is 200 s
The deposition rate tends to decrease as the H2 gas flow rate increases to 500 sccm and 500 sccm.
Even in the case of sec, high-speed film formation of 6 μm/hour or more can be obtained.

[Example 2] In this example, by the same manufacturing operation as [Example 1], a
A -SiC:H carrier transport layer was produced on a NESA glass plate and the conductivity of the layer was measured. The results are shown in Table 5.

That is, FIG. 5 shows the atomic composition ratio of Si and C in the film (C/Si
+C) represents the electrical conductivity, and Q marks, △ marks, and 0
The marks indicate that H2 gas is not added, flow rate is 200 sccm,
Plot for flow rate 1500 sec, d.

e and f are respective characteristic curves. As is clear from this figure, if the (C/Si +C) ratio is within the range of o, i to 0.9, the conductivity will be 10-'' Ω·cm or less.

[Example 3] An aluminum drum for a substrate finished to a mirror finish using an ultra-precision lathe using a diamond cutting tool was cleaned by ultrasonic cleaning and steam cleaning using an organic solvent, and then by drying.
It was installed in the reaction tube (28) of the capacitively coupled glow discharge decomposition apparatus shown in FIG. Then, SiH4 gas was supplied from the first tank (6), C2H2 gas was supplied from the second tank (7), and BzHi gas (H2 dilution 200%) was supplied from the fourth tank (9).
0ppm) from the fifth tank (10), BzH6 gas (
H2 diluted to 2000 ppm), H2 gas from the fifth tank (10), and No gas from the sixth tank (11) at flow rates of 180 sccm, 90 sccm, and 90 s, respectively.
ccm.

200 sccm, discharge to 8 scCm, gas pressure to Q, 4 Torr, high frequency power to 0.2 W/c
m'', and a carrier injection blocking layer (5) with a thickness of 2 μm was formed based on the glow discharge decomposition method.

Next, close the fourth and sixth regulating valves (15) and (17),
SiH4 gas is supplied from the first tank (6) and the second tank (7
), the total flow rate of C2Ht gas is 270s.
ecm, and further H2 gas is released from the fifth tank (10) for 50 sec and 200 sc as necessary.
cm, at a flow rate of 500 sec, and the gas pressure was set to 0.
A carrier transport layer (2a) having a thickness of 25 μm was formed based on the glow discharge decomposition method described above at a pressure of 5 Torr and a high frequency power of 0.4 W/cm”.

Next, 5iHa gas, CzHz gas, GeHa gas, and H2 gas were each supplied at 200 sccm by the same operation.
, 20 sccm+90 sec, and 250 sec, the gas pressure was set to 0°5 Torr, and the high frequency power was set to 0.4 W/cm'' to form a carrier generation layer (3a) with a thickness of 5 μm.

After that, the third. Close the fifth regulating valve (14) (16) and supply 150scc of SiH4 gas and CzHz gas each.
m and 101005c, and the gas pressure was 0.3
A surface protective layer with a thickness of 0.5 μm was formed using a high-frequency power of 0.4 W/cm” under Torr.

The surface potential, photosensitivity (when a semiconductor laser with an oscillation wavelength of 780 r+m was used as a light projection source), residual potential, and image quality were measured for the photoreceptors A to I thus obtained, and the results were as shown in Table 1. Obtained.

In the table, the ◎ mark for image quality evaluation means that the image quality contrast is high and no ghost phenomenon occurs at all even when high-speed copying (copying at 50 sheets/min or more) is performed, and the O mark indicates that a slight ghost phenomenon occurs when high-speed copying is performed. However, there is no practical problem,
The mark X indicates a case where the residual potential is high and the white background is noticeably blurred, making it unsuitable for practical use.

In addition, in this example, the manufacturing conditions of the a-SiC:H carrier transport layer set for each of photoreceptors A to I,
That is, with the same (C/Si+C) ratio and H2 gas flow rate, only the a-3iC:H carrier transport layer was produced on a silicon single crystal flat plate by the same manufacturing operation as [Example 1],
In contrast, the wave number of 2090 cm-' and the wave number of 2860 cm
The infrared absorption coefficient of each wavenumber of -' was measured, and the results are shown in Table 1.

As is clear from Table 1, photoreceptors A to E and G are excellent photoreceptors suitable for practical use and can be provided as photoreceptors for high-speed copying, and photoreceptors A to C in particular have high photosensitivity. Because of its excellent charging ability, no ghost phenomenon occurred even during high-speed copying. However, the photoreceptors F, H,
I was not suitable for practical use due to the noticeable ghost phenomenon.

According to this example, the evaluation means for determining the superiority or inferiority of the photoreceptor is that the infrared absorption coefficient of the carrier transport layer has an absorption coefficient within a predetermined range for a predetermined wave number, and from Table 1, As revealed, its absorption coefficient is 2090 cm
-' wavenumber is 1000 or more and 2860
It can be seen that the photoreceptor of the present invention can be obtained if the wave number of cm-' is 1000 or less.

Furthermore, in forming the carrier transport layer (2a) in this example, the fourth regulating valve (15) was opened to supply 10% of the BzHa gas.
105e to form a layer (2a) containing B, and the same image quality evaluation was obtained for each of the nine types of photoreceptors corresponding to photoreceptors A to I obtained thereby.

Further, when the spectral sensitivity of photoreceptor A was measured, the results shown in FIG. 6 were obtained.

That is, the mark in FIG. 6 is a plot representing the spectral sensitivity of photoreceptor A, whereas the plot of the spectral sensitivity of the photoreceptor (comparative example) consisting of a carrier generation layer that does not contain Ge is O.
The curves are indicated by marks, and are characteristic curves for g and hi. The photoreceptor of this comparative example is the same as photoreceptor A except for the carrier generation layer, and when forming this carrier generation layer, GeH4 gas was not used and 5iHa gas was used.
Gas, Cz) Iz gas and H2 gas are used, and the respective flow rates are 200 sccm, 20 sccm and 2
Set the gas pressure to 50 sccm and set the gas pressure to Q, 5 Torr.
, the high frequency power was set to 0.4 W/cm'', thereby forming a carrier generation layer with a thickness of 5 μm.

As is clear from FIG. 6, it can be seen that photoreceptor A has better photosensitivity at a wavelength of about 780 nm than the photoreceptor of the comparative example.

[Example 4] In this example, when manufacturing photoreceptor A of [Example 3], the surface potential, photosensitivity, residual potential, and Adhesion was measured.

The measurement results are shown in Table 2, and the adhesion was determined by immersing the photoreceptor in liquid nitrogen and then leaving it at room temperature.
A test was conducted in which the temperature cycle of immersion in liquid nitrogen was repeated 10 times, and those in which no pinholes occurred were marked with a ◎ mark. The X mark indicates a case where pinholes exceeding 0.5 φ have occurred at a relatively high density.

As is clear from Table 2, L was added to the photoreceptor of the present invention.

The gate has excellent photosensitivity and adhesion, whereas photoreceptors J and N have poor adhesion or photosensitivity and are not suitable for practical use.

〔Effect of the invention〕

As described above, according to the electrophotographic photoreceptor of the present invention, it is possible to improve the dark resistivity and carrier mobility of the a-SiC:H carrier transport layer formed for a functionally separated photoreceptor. The dark decay rate of the photoreceptor can be reduced and the charging ability can be increased, and as a result, an electrophotographic photoreceptor suitable for high-speed copying can be provided. Since this photoreceptor has excellent photosensitivity to a wavelength of about 780 r+m, it is particularly useful for semiconductor laser printers.

Further, according to the electrophotographic photoreceptor of the present invention, the ratio of Si to C in a-5iC used in the carrier injection blocking layer, carrier transport layer, carrier generation layer, and surface protective layer can be set within a large range, and the Si and C ratios can be set within a large range. Each of the gas and the C supply gas can be used in common for forming each layer, and as a result, the same gas flow rate control system can be used, making it easy to control the individual gas flow rates.
As a result, manufacturing control becomes easier and manufacturing efficiency can be improved. Furthermore, SiH, gas and CzHz
A carrier injection blocking layer, a carrier transporting layer, a carrier generating layer, and a surface protective layer can be formed continuously and at high speed using the same film forming apparatus by a glow discharge decomposition method using gas as a raw material. Manufacturing efficiency can be increased and manufacturing costs can be significantly reduced.

Furthermore, according to the electrophotographic photoreceptor of the present invention, the adhesion of the carrier generation layer to the underlying layer is improved, and as a result,
White spots etc. do not occur in images, and long life and high reliability can be achieved.

[Brief Description of the Drawings] Fig. 1 is a sectional view showing the N structure of a functionally separated electrophotographic photoreceptor according to the present invention, and Fig. 2 is a sectional view showing the layer structure of a conventional functionally separated electrophotographic photoreceptor. , FIG. 3 is an explanatory diagram of the capacitively coupled glow discharge decomposition device used in the embodiment of the present invention, FIG. 4 is a diagram showing the film formation rate of the carrier transport layer of the photoreceptor according to the present invention, and FIG. 6 is a diagram showing the electrical conductivity of the carrier transport layer of the photoreceptor according to the present invention, and FIG. 6 is a diagram showing the spectral sensitivity of the photoreceptor. 1 ・ ・ ・ Base 2.2a...Carrier transport layer 3.3a...Carrier generation layer 4.4a...Surface protection layer 5...Carrier injection blocking layer

Claims (1)

[Claims] A laminate comprising at least a carrier injection blocking layer, a carrier transport layer, and a carrier generation layer formed on a substrate,
The carrier injection blocking layer is made of amorphous silicon carbide, and the atomic composition ratio of carbon and silicon is 1:
9 to 9:1, the carrier generation layer is made of amorphous silicon germanium carbide, the atomic composition ratio of silicon to germanium is within the range of 1:1 to 19:1, and the atomic composition ratio of silicon to carbon is within the range of 1:1 to 19:1. is in the range of 1:1 to 19:1, the carrier transport layer is made of hydrogenated amorphous silicon carbide, the atomic composition ratio of carbon to silicon is in the range of 1:9 to 9:1, and the infrared absorbing layer is 286 in the spectrum
An electrophotographic photoreceptor having an absorption coefficient at 0 cm^-^1 of 1000 or less and an absorption coefficient at 2090 cm^-^1 of 1000 or more.