JPH0495965A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance photosensitivity from a shorter wavelength region to the long wavelength region of the whole visible light region by forming a carrier exciting layer comprising an a-SiC layer and an a-SiGe layer of a laminated tandem structure. CONSTITUTION:The first amorphous silicon carbide a-Si1-xCx layer 2, (0.2 < x < 0.5), the amorphous silicon-germanium a-SiGe layer 3, and the second a-Si1-yCy layer 4 (0 < y < 0.5), are successively laminated on a substrate 1, and further, an organic semiconductor layer 5 is laminated, thus permitting light incident on the surface side of the layer 5 to have the short wavelength side mainly absorbed by the layer 4 and the long wavelength side mainly absorbed by the layer 3, and therefore photosensitivity in the whole visible light region to be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor comprising a laminated layer of an amorphous silicon carbide layer or an amorphous silicon germanium layer and an organic optical semiconductor layer.

[Prior art and its problems]

The electrophotographic photoreceptor proposed in JP-A-56-14241 has a structure in which amorphous silicon carbide (hereinafter amorphous silicon carbide is abbreviated as a-3iC) and an organic optical semiconductor layer are laminated on a substrate. −
The 3iC layer is used as a carrier excitation layer.

However, according to the electrophotographic photoreceptor having the above structure, the a-SiC layer has a large optical bandgap, so the sensitivity on the short wavelength side is good, but on the other hand, the sensitivity on the long wavelength side is insufficient. As a result, when used in a PPC (plain paper copier), the sensitivity is insufficient in the wavelength range of 60 Qnm or more, which ranges from yellow to red, and as a result, for color originals, etc., the sensitivity is poor in the visible range. The problem is that it cannot be done. Furthermore, when used in printers that use long-wavelength light sources, such as laser beam printers and LED printers, there is also the problem of insufficient sensitivity.

Furthermore, in the electrophotographic photoreceptor proposed in JP-A No. 56-25743, an amorphous silicon photosensitive layer (hereinafter amorphous silicon is abbreviated as a-3i), an a-3iC transition layer, and an organic photoconductor are formed on a substrate. The a-3i layer and the a-SiC layer are stacked one after another.
When multiple layers are stacked, the sensitivity characteristics are improved, but on the other hand, the dark decay characteristics of the surface potential deteriorate, and the dark decay becomes faster. There is a problem that large surface potential unevenness occurs in the subsequent developing section, and as a result, density unevenness of the image becomes noticeable, making it impossible to obtain a good image. Furthermore, when used in printers that use long wavelength light sources, such as laser beam printers and LED printers, there is also the problem of insufficient sensitivity.

Further, when the a-3i layer is laminated directly on the substrate, there is a problem that the adhesion between the layer and the substrate is insufficient and peeling occurs.

Therefore, the purpose of the present invention is to obtain high photosensitivity over the entire visible light range from short wavelengths to long wavelengths, improve the dark decay characteristics of the surface potential, and achieve high reliability in which good images can be stably obtained. An object of the present invention is to provide an electrophotographic photoreceptor.

[Means for solving problems]

The electrophotographic photoreceptor of the present invention has an atomic composition ratio of S1□ on a substrate.
- the first y-value of C, in the range 0.2<x<0.5
a-3iC layer and amorphous silicon germanium layer (hereinafter amorphous silicon germanium is referred to as a-3i
a second a-3iC layer having an atomic composition ratio of si, a y value of -yCy (1<y<Q, 5);
It is characterized by sequentially stacking organic optical semiconductor layers.

Further, in the electrophotographic photoreceptor of the present invention, the first a-3iC layer contains 1 to 10.000 ppm of a group Iua element of the periodic table or 5.000 ppm or less of a group Va element, and is positively charged or negatively charged, respectively. Another feature is that it is a charged type.

Furthermore, the electrophotographic photoreceptor of the present invention has the above-mentioned first a-3i
Another feature is that the C layer contains 0.01 to 30 atomic percent of oxygen and/or nitrogen.

The present invention will be explained in detail below.

1 and 2 show the layer structure of the electrophotographic photoreceptor of the present invention. Both have a first a-3iC layer 2, a-3 on the substrate l.
An iGe layer 3 and a second a-SiC layer 4 are sequentially laminated, and an organic optical semiconductor layer 5 is further laminated. FIG. 2 shows another example, in which an inorganic protective layer 6 is laminated on the organic optical semiconductor layer 5.

In the above layer structure, the first a-3iC layer 2 has the function of blocking the injection of carriers from the substrate 1 when the photoreceptor is charged, and also improves the adhesion between the photosensitive layer and the substrate 1 to form a film. It has a function to prevent peeling.

The a-3iGe layer 3 and the second a-3iC layer 4 have a function of generating charges, and the organic optical semiconductor layer 4 has a function of transporting charges.

According to this layer structure, the second a-8iC layer 4 absorbs mainly the light on the short wavelength side of the light incident from the surface side of the organic optical semiconductor layer 5, and then the remaining light mainly on the long wavelength side is absorbed. is a-
3iGe layer 3, and as a result, the photosensitivity is increased in the entire visible region.

First, for the first a-3iC layer 2, the range of element ratios is set as follows.

5t1-xCx 0.2<x<0.5 Preferably 0.3x<0.5 If the X value is less than 2, carrier injection from the substrate 1 cannot be sufficiently prevented, and Attenuation characteristics cannot be improved, and adhesion to the substrate 1 cannot be sufficiently ensured. When the X value is 0.5 or more, the a-3iGe layer 3 and the second a
-3 Photocarriers generated in the iC layer 4 do not flow smoothly to the substrate 1, resulting in a decrease in photosensitivity and an increase in residual potential.

Moreover, the thickness of the first a-3iC layer 2 is 0.01 to 1.0
μm, preferably within the range of 0.05 to 0.5 μm,
Within this range, good dark decay characteristics can be obtained and the adhesion of the film will also be good.

Furthermore, the optical energy gap of the first a-3iC layer 2 is preferably increased to provide a difference of 0.1 eV or more, preferably 0.2 eV or more, compared to the a-3iGe layer 3. injection of carriers can be effectively prevented.

Further, in the present invention, the first a-3iC layer 2 may contain 1 to 10.000 ppm, preferably 100 to 5.000 ppm, of an element from group Ia of the periodic table. Among the carriers, injection of particularly negative charges can be prevented, and dark decay characteristics can be improved. Its content is 1
If it is less than ppm, the above effects cannot be obtained, and 1
If it exceeds 0.000 ppm, defects inside the layer increase and the film quality deteriorates, resulting in a decrease in surface potential and an increase in residual potential.

In addition, in incorporating the first group a element, the substrate 1
By gradually decreasing the photocarriers, especially positive charges, generated in the excitation layer in the layer thickness direction toward the surface of the photoreceptor, it is possible to smoothly flow the photocarriers, especially positive charges, generated in the excitation layer toward the substrate side. It can be prevented from flowing into the layer, thereby further improving the dark decay properties, further increasing the photosensitivity, and further reducing the residual potential. When a gradient distribution is provided in this way, the maximum content is also 1 to 10.00.
0 ppm, preferably 100-5. Just set it to oooppm.

Above 1 [group a elements include B, AI! , Ga, I
Among them, element B is desirable because it has excellent covalent bonding properties and can sensitively change semiconductor properties, and also because it can provide excellent charging ability and photosensitivity.

Further, in the present invention, the first a-3iC layer 2 contains an element of Group Va of the periodic table in an amount of 5.000 ppm or less, preferably 3.
00 to 3.000 ppm may be contained, in this case,
Among carriers from the substrate 1, injection of positive charges in particular can be prevented, and dark decay characteristics can be improved. Its content is 5,000
If it exceeds ppm, defects inside the layer will increase, the film quality will deteriorate, and the surface potential will decrease and the residual potential will increase.

In addition, when including the Group Va element, by gradually decreasing it in the layer thickness direction from the substrate 1 toward the surface of the photoreceptor, photocarriers, especially negative charges generated in the excitation layer can smoothly flow toward the substrate. Furthermore, it is possible to prevent carriers, particularly positive charges, from the substrate side from flowing into the photoreceptor layer, thereby further improving dark decay characteristics, further increasing photosensitivity, and further reducing residual potential. When a gradient distribution is provided in this way, the maximum content is also 5.000 ppm.
The following range is preferably 300 to 3. It can be set to OOOppm.

The Group Va elements include N, P, As, Sb,
Bi, especially P, is desirable because it has excellent covalent bonding properties and can sensitively change semiconductor properties, and also because it provides excellent charging ability and photosensitivity.

In the a-3iGe layer 3, carriers are well excited by long wavelength light, and its photosensitivity can be increased.

For this purpose, the thickness of the layer is desirably set within the range of 0.05 to 5.0 μm, preferably 0.1 to 3.0 μm.

Furthermore, when the optical energy gap (hereinafter abbreviated as Eg Opt) of this a-3iGe layer 3 is set within the range of 1.4 to 1.8 eV, good photoconductivity and high photosensitivity can be obtained. It will be done.

The element ratio of the a-3iGe layer 3 is 5ll-IQ Ge
, where m value is 0.05<m<0.5, preferably 0.1
<m<O; It is desirable to set it within the range of 4, and within this range, the photoconductivity can be increased and the photosensitivity on the long wavelength side can be significantly increased.

Regarding the second a-3iC layer 4, the element ratio is set as follows.

St+-yCy o<y<0. s Preferably 0.05 < 7 < 0.4 Optimally Q, l < y < 0.3 If the y value is 0.5 or more, the photoconductivity will be extremely low and the photocarrier excitation function will be impaired. As a result, the photosensitivity decreases, and the residual potential also increases.

Further, the thickness of the second a-3iC layer 4 is set to 0.05 to 3.01.
When t m is preferably set within the range of 0.1 to 2.5 μm, carrier excitation by short wavelength light is performed satisfactorily, and the photosensitivity on the short wavelength side can be sufficiently increased.

Furthermore, E opt of the second a-SiC layer 4 is a-S
0. compared to iGe layer 3. tev or more, preferably 0.2
What is necessary is to set it so that it becomes larger than eV, so that light on the long wavelength side reaches the a-3iGe layer 3 without being absorbed much.

In addition, if it is a positively charged electrophotographic photoreceptor, a-S iGe
The layer 3 and/or the second a-3iC layer 4 each contain 500 ppm or less of Group Va elements of the periodic table, preferably 110 ppm or less.
When the content is within the range of 0 pp or less, the photosensitivity can be further increased. This group Va element includes NP, As
, Sb, Bi, or the P element is desirable because it has excellent covalent bonding properties and can sensitively change semiconductor properties, and also because it provides excellent charging ability and photosensitivity.

Furthermore, in the case of a negatively charged electrophotographic photoreceptor, the a-3iGe layer 3 and/or the second a-3iC layer 4 contain 1 to 11,000 pp or less, preferably 3 to 11,000 pp of an element from group IV of the periodic table.
When contained within the range of 0 to 300 ppm, photosensitivity can be further enhanced. This first [a group element includes B,
Aβ, Ga, In, etc., or B elements are desirable because they have excellent covalent bonding properties and can sensitively change semiconductor properties, and also provide excellent charging ability and photosensitivity.

Each of the above three types of layers 2. 3. 4 are amorphous layers, and their dangling bonds are terminated with hydrogen (H) elements or halogen elements. The content of the element A (H or halogen) in the a-3iGe layer 3 and the second a-3iC layer 4 is preferably set within the following ranges.

When expressed as a binary value by a (StGe) + - z A z a - (SiC) + - z A, 0.05 < z < 0.5, preferably 0.1 < z < 0.45. The photographic photoreceptor can be of a negatively charged type or a positively charged type depending on the material selection of the organic photosemiconductor layer 5. That is, in the case of a negatively charged electrophotographic photoreceptor, an electron-donating compound is selected for the organic photosemiconductor layer 5, while in the case of a positively charged electrophotographic photoreceptor, an electron-withdrawing compound is selected for the organic photosemiconductor layer 5. To be elected.

The electron-withdrawing compound may have a high molecular weight, such as poly-
These include N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, pyrene-pormaldehyde condensation polymers, and low molecular weight ones such as oxadiazole, oxazolepyrapurine, triphenylmethane, hydrazone, triarylamine, and N-phenyl. Examples include carbazole and stilbene, and these low-molecular substances are used after being dispersed in binders such as polycarbonate, polyester, methacrylic resin, polyamide, acrylic epoxy, polyethylene, phenol, polyurethane, butyral resin, polyvinyl acetate, and urea resin. .

Examples of the electron-withdrawing compounds include 2.4.7-IJ nitrofluorenone.

The substrate 1 may be a metal conductor such as copper, brass, SO3, AA', or Ni, or an insulator such as glass or ceramics coated with a conductive thin film.

This substrate 1 may be a flexible conductive sheet in the form of a sheet, belt or web. Such a sheet has 81, N
i. Metal sheets such as stainless steel, or polymer resins such as polyester films, nylon, and polyimide are coated with metals such as AA and Ni, or SnO□, and composite oxides of indium and tin: ITO (Indium Tin).
A transparent conductive material such as (Oxide) or an organic conductive material that has been subjected to conductive treatment such as vapor deposition is used.

Furthermore, a protective layer 6 may be provided as shown in FIG. This layer 6 is an a-3i layer or an a-3iC layer (its elemental ratio is in the range of 0≦a<0.95, preferably 0.5<a<0.95 with a value of 5ll-aca) ), or the aSi layer or the a-3iC layer may contain elements such as nitrogen or oxygen. By providing such a layer as the protective layer 6, wear resistance is improved compared to when the organic optical semiconductor layer is exposed on the surface. Moreover, since the surface of the protective layer 6 is chemically stable and does not undergo deterioration, only image fading occurs during long-term use.

Furthermore, when the first a-3iC layer 2 contains the element B of oxygen and/or nitrogen in the total amount as shown below, the adhesion to the substrate 1 and the release from the substrate 1 are improved compared to the case where the element B is not contained. The ability to stop carrier injection is enhanced.

(Si+-8C8)14B.

0.0001<b<0.3 Preferably 0.001<b<0.1 Next, a method for manufacturing the electrophotographic photoreceptor of the present invention will be described.

a first a-3iC layer 2, an a-3iGe layer 3 and a second a-3iC layer 2;
The -3iC layer and the protective layer 6 made of a-3i, a-3iC, amorphized Si-C-N elements, Si-C-0-N elements, etc. are formed using glow discharge decomposition method, ionization method, etc. There are thin film forming methods such as a brating method, a reactive sputtering method, a vacuum evaporation method, and a CVD method.

When forming a SiC layer using glow discharge decomposition method, S
A gas containing an i element and a gas containing a C element are combined, and this mixed gas is subjected to plasma decomposition to form a film.

This Si element-containing gas contains SiH4, Si2Hs, S
i3Hs.

5IF4.5IC14, SiHC1s, etc., and C element-containing gases include CH4, C2H4, C2H2, C
-Ha, etc., and C2H2 is particularly desirable in that it can provide high-speed film formation.

The organic photosemiconductor layer is formed by a dip coating method or a coating method. According to the latter coating method, a photosensitive material dispersed in a solvent is applied using a coater, and then dried with hot air.

Thus, according to the electrophotographic photoreceptor of the present invention, since the carrier excitation layer has a tandem structure in which the a-3iC layer and the a-3iGe layer are laminated, light incident from the organic optical semiconductor layer 5 side is transmitted to the second layer. The a-3iC layer 4 mainly absorbs light on the short wavelength side, and then the a-3iGe layer 3 absorbs mainly the light on the long wavelength side that has passed through the layer 4.
Compared to an excitation layer consisting of a -3iC layer alone, the photosensitivity is increased over the entire visible region, and the residual potential is reduced.

Furthermore, as shown in Fig. 3, if the electrophotographic photoreceptor R has a structure in which an a-SiGe layer and an a-3iC layer are laminated directly on the substrate, the a-3iGe layer can effectively inject carriers from the substrate. Since this cannot be prevented, the dark decay of the surface potential becomes faster due to the injected carriers, and as a result, the decrease in the surface potential from the charging section to the developing section in the electrophotographic process increases.

Further, small unevenness in charging at the charging section results in large unevenness in surface potential at the developing section, which results in large unevenness in image density, making it difficult to obtain good image characteristics. Furthermore, if the dark decay is fast, fluctuations in the surface potential at the developing section tend to be large, making it difficult to stably obtain images of good quality during continuous use. On the other hand, in the case of the electrophotographic photoreceptor T of the present invention, the dark resistance is higher than that of the a-3iGe layer, and the first a-
Since the 3iC layer 2 is provided and can effectively block carrier injection from the substrate 1 and slow dark decay, the above-mentioned problems can be solved.

〔Example〕

Next, examples of the present invention will be described.

(Example 1) AI! A first a-3iC layer 2, an a-3iGe layer 3 and a second a-3i
C layers 4 were sequentially laminated.

Next, an organic optical semiconductor layer 5 was formed to a thickness of 15 μm.

In its formation, 2.4.7-trinitorenone was dissolved in a solvent of 1.4-dioxane, a polyester resin (Refsan-LS2-11) was added, and ultrasonic dispersion was performed for 40 minutes. The resulting solution was applied using a bar coater and then dried with hot air at 80°C.

[Left below] In the positively charged electrophotographic photoreceptor thus obtained,
Carbon content ratio (X value and y value), germanium content ratio (m value), H content ratio (Z value), and Eg of each layer
opt was determined by plotting (αhν)1'' versus hν of the transmitted light spectrum measured by X-ray microanalysis, infrared absorption method, and visible light spectrometer, and the results shown in Table 1 were obtained. .

Further, in producing the electrophotographic photoreceptor of this example, the first a-3iC layer and the a-3iGe layer were not formed, and the second a-3iC layer and the a-3iGe layer were not formed.
Comparative Example A was obtained by forming only the 3iC layer and forming the rest in the same manner as in this example.

Furthermore, in producing the electrophotographic photoreceptor of this example, the first a-3iC layer was not formed, only the a-3iGe layer and the second a-3iC layer were formed, and the rest was the same as in this example. Comparative Example B was formed.

When the spectral sensitivities of the electrophotographic photoreceptor of the present invention and Comparative Example A were measured, the results shown in FIG. 4 were obtained. In the figure, the horizontal axis is the wavelength, and the vertical axis is the photosensitivity, and the change in surface potential in response to exposure with a light intensity of 0.3 μW/cm at each wavelength was measured using a surface electrometer with a light transmission probe. It was determined by the reciprocal of the exposure amount required to halve the surface potential.

As is clear from the results shown in FIG.
It can be seen that the photosensitivity is higher on the long wavelength side of 600 nm or more compared to the above.

In addition, the photosensitivity of Comparative Example B was similar to that of this example, but on the other hand, when we followed the progress of the surface potential in the dark after charging, we found that the photosensitivity of this example was as shown in Figure 5. It can be seen that the dark decay of the surface potential is faster than that of the body, the charge is low, and the potential unevenness is large.

Furthermore, when the photoreceptor of this example and Comparative Example B were left in an environment of 35°C and 95% RH for 24 hours, no change was observed in the photoreceptor of this example, whereas in Comparative Example B, the substrate It was also confirmed that the film peeled off from the a-3iGe layer and there was a problem with the adhesion of the film.

(Example 2) In producing an electrophotographic photoreceptor similar to (Example 1),
By changing the film forming conditions, the first a-3iC layer, a-3iG
Ten types of photoreceptors A to J shown in Table 2 were prepared by changing the composition and thickness of the e layer and the second a-3iC layer, and the dark decay, photosensitivity, and residual amount of each photoreceptor were measured. The potential was evaluated. When the Z value of each layer in the table was measured by IR method, all of them were within the range of 0.05<z<0.5.

In addition, regarding dark decay, photosensitivity, and residual potential in the table, ◎ marks are cases where the best results were obtained, ○ marks are cases where somewhat better results were obtained, and Δ marks are cases where slightly better results were obtained. This is a case where an inferior result is obtained.

[Margin below]

As is clear from the results shown in Table 2, it can be seen that photoreceptors D to G are excellent in all of dark decay, photosensitivity, and residual potential.

(Example 3) A [first a
-3iC layer 2, a-3iGe layer 3 and second a-3iC
Layers 4 were laminated in sequence.

Next, the organic optical semiconductor layer 5 was formed to a thickness of 15 μm in the same manner as in (Example 1).
It was formed with

[Margin below]

In the positively charged electrophotographic photoreceptor thus obtained,
When the total content of N and O elements in the first a-SiC layer was measured, it was 4.0 at%, and the carbon content ratio (X value and y value) and germanium content ratio (
When the H content ratio (Z value) and Eg Opt were determined, the results shown in Table 3 were obtained.

Further, in producing the electrophotographic photoreceptor of this example, the first a-SiC layer and the a-SiGe layer were not formed, and the second a-SiC layer and the a-SiGe layer were not formed.
Comparative Example C was obtained by forming only the -SiC layer and forming the others in the same manner as in this example.

Furthermore, in producing the electrophotographic photoreceptor of this example, No gas was not introduced during the formation of the first a-3iC layer;
The 3iGe layer and the second a-3iC layer were formed in the same manner, and the others were formed in the same manner as a comparative example.

When the spectral sensitivities of the electrophotographic photoreceptor of the present invention and Comparative Example C were measured, the same results as shown in FIG. 4 were obtained.

In addition, the photosensitivity of the comparative example was similar to that of this example, but on the other hand, when we followed the progress of the surface potential in the dark after charging, the surface potential was higher than that of the photoreceptor of this example. It was found that the dark decay was about 20% faster, the charge was low, and the potential unevenness was large.

(Example 4) In producing an electrophotographic photoreceptor similar to (Example 3),
By changing the No gas and changing the total content of 0 and N elements in the first a-3iC layer, eight types of -R photoreceptors were prepared as shown in Table 4. Attenuation, photosensitivity and residual potential were evaluated. When the Z value of each layer in the table was measured by IR method, all were 0.05<z<0
．． It was within the range of 5.

[Margin below]

As is clear from the results shown in Table 4, it can be seen that photoreceptors L to Q are excellent in all of dark decay, photosensitivity, and residual potential.

(Example 5) Using a capacitively coupled glow discharge decomposition apparatus for producing an electrophotographic photoreceptor, the first a
-SiC layer 2, a-SiGe layer 3 and second a-3iC
Layers 4 were laminated in sequence.

Next, an organic optical semiconductor layer 5 was formed to a thickness of 15 μm.

In its formation, 2.4.7-)linitrofluorenone was dissolved in a 1.4-dioxane solvent, a polyester resin (Refsan-LS2-11) was added, and ultrasonic dispersion was performed for 40 minutes. The resulting solution was applied using a bar coater and then dried with hot air at 80''C.

[Margin below] *marks are outside the scope of the present invention.

In the positively charged electrophotographic photoreceptor thus obtained,
When the B element content of the first a-3iC layer was measured using a secondary ion mass spectrometer, it was 1.000 ppm,
Furthermore, when the carbon content ratio (X value and y value), H content ratio (Z value), and Egopt of each layer were determined, the results shown in Table 5 were obtained.

Further, in producing the electrophotographic photoreceptor of this example, the first a-3iC layer and the a-3iGe layer were not formed, and the second a-3iC layer and the a-3iGe layer were not formed.
Comparative Example E was obtained by forming only the 3iC layer, and forming the rest in the same manner as in this example.

Furthermore, in producing the electrophotographic photoreceptor of this example, the first a-3iC layer was not formed, only the a-3iGe layer and the second a-3iC layer were formed, and the rest was the same as in this example. Comparative Example F was prepared.

When the spectral sensitivities of the electrophotographic photoreceptor of the present invention and Comparative Example E were measured, the results shown in FIG. 4 were obtained.

As is clear from the results shown in FIG.
It can be seen that the photosensitivity is higher on the long wavelength side of 600 nm or more compared to the above.

In addition, the photosensitivity of Comparative Example F was similar to that of this example. On the other hand, when we followed the progress of the surface potential in the dark after charging, we found that the surface potential was lower than that of the photoreceptor of this example. It was found that dark decay was fast, charging was low, and potential unevenness was large.

Furthermore, when the photoconductor of this example and Comparative Example F were left in an environment of 35°C and 95% RH for 24 hours, no change was observed in the photoconductor of this example, whereas in Comparative Example F, the substrate It was also confirmed that the film peeled off from the a-3iGe layer, and there was a problem in the adhesion of the film.

Furthermore, in producing the photoreceptor of this example, the first a-
B2Hg gas was not introduced during the formation of the 3iC layer, and the other conditions were set to be exactly the same, thereby producing a positively charged electrophotographic photoreceptor having the first a-3iC layer containing no B element. Created.

When the characteristics of this electrophotographic photoreceptor were evaluated, the spectral sensitivity on the long wavelength side of 600 nm or more was almost the same as that of the photoreceptor of this example, but on the other hand, compared to the photoreceptor of this example, The dark decay of the surface potential was about 20% faster, the charging was low, and the potential unevenness was large.

(Example 6) In producing an electrophotographic photoreceptor similar to (Example 5),
Ten types of photoreceptors A to J shown in Table 6 were prepared by changing the B2H and gas flow rates and the B element content of the first a-3iC layer 2, and the dark decay of each photoreceptor was , photosensitivity and residual potential were evaluated.

[Margin below] No. table *marks are outside the scope of the present invention.

As is clear from the results shown in Table 6, it can be seen that photoreceptors B to (2) are excellent in all of dark decay, photosensitivity and residual potential.

(Example 7) Using a capacitively coupled glow discharge decomposition apparatus for producing electrophotographic photoreceptors, the first a was deposited on an Al substrate under the film forming conditions shown in Table 7.
-3iC layer 2, a-3iGe layer 3 and second a-3iC
Layers 4 were laminated in sequence.

Next, the organic optical semiconductor layer 5 was formed to a thickness of 15 μm in the same manner as in (Example 5).
It was formed with

[Margin below]

In the electrophotographic photoreceptor thus obtained, the first a-
When the content of B element and the total content of O and N elements in the 3iC layer were measured using a secondary ion mass spectrometer, they were found to be 1.000 ppm and 4 atomic %, respectively.

Further, in producing the electrophotographic photoreceptor of this example, the first a-SiC layer and the a-3iGe layer were not formed, and the second a-SiC layer and the a-3iGe layer were not formed.
Comparative Example G was obtained by forming only the 3iC layer and forming the other parts in the same manner as in this example.

Furthermore, in producing the electrophotographic photoreceptor of this example, the first a-3iC layer was not formed, but the a-3iGe layer and the second a-3iC layer were formed in the same manner, and the rest was the same as in this example. Comparative Example H was obtained.

When the spectral sensitivities of the electrophotographic photoreceptor of the present invention and Comparative Example G were measured, results similar to those shown in FIG. 4 were obtained.

In addition, the photosensitivity of Comparative Example H was similar to that of this example, but on the other hand, when we followed the course of the surface potential in the dark after charging, we found that the surface potential was higher than that of the photoreceptor of this example. It was found that the dark decay was fast, the charge was low, and the potential unevenness was large.

Furthermore, when the photoconductor of this example and Comparative Example H were left in an environment of 35°C and 95% RH for 24 hours, no change was observed in the photoconductor of this example, while the substrate of Comparative Example H It was also confirmed that peeling of the film occurred between the film and the a-3i layer, and that there was a problem with the adhesion of the film.

Furthermore, in producing the electrophotographic photoreceptor of this example, B2H@ gas and NO gas were not introduced during the formation of the first a-3iC layer, and the other conditions were set to be exactly the same. A positively charged electrophotographic photoreceptor including a first a-3iC layer containing no element, 0 element, and N element was produced.

When the characteristics of this electrophotographic photoreceptor were evaluated, the spectral sensitivity on the long wavelength side of 600 nm or more was almost the same as that of the photoreceptor of this example, but on the other hand, compared to the photoreceptor of this example, The dark decay of the surface potential was about 25% faster, the charging was low, and the potential unevenness was large.

(Example 8) In producing an electrophotographic photoreceptor similar to (Example 6),
By changing the 82H6 gas flow rate and the NO gas flow rate, the first a
-3 Eleven types of photoreceptors of -U as shown in Table 8 were prepared by changing the B element content and the total content of 0 element and N element in the iC layer, and the dark decay, photosensitivity and The residual potential was evaluated.

[Margin below]

As is clear from the results shown in Table 8, it can be seen that the photoreceptors M to S are excellent in all of dark decay, photosensitivity, and residual potential.

(Example 9) Using a capacitively coupled glow discharge decomposition apparatus for producing an electrophotographic photoreceptor, the first a
-3iC layer 2, a-3iGe layer 3 and second a-3iC
Layers 4 were laminated in sequence.

Next, an organic semiconductor layer 5 was formed to a thickness of 15 μm.

According to its formation, hydrazone is dissolved in a solvent of 1,4-dioxane, and then polyester resin (Refsan-LS2-11) is added in the same weight as hydrazone, and
Ultrasonic dispersion was performed for 40 minutes, and the resulting solution was applied using a bar coater, followed by hot air drying at 80°C.

[Margin below]

*marks are outside the scope of the present invention.

In the negatively charged electrophotographic photoreceptor thus obtained,
P element content of first a-3iC layer and second total SiC
When the B element content of the layers was measured, they were 2. O
OOppm and 1100pp.

Further, in producing the electrophotographic photoreceptor of this example, the first a-3iC layer and the a-3iGe layer were not formed, and the second a-3iC layer and the a-3iGe layer were not formed.
Comparative Example I was obtained by forming only the 3iC layer and forming the other parts in the same manner as in this example.

Furthermore, in producing the electrophotographic photoreceptor of this example, the first a-3iC layer was not formed, only the a-3iGe layer and the second a-3iC layer were formed, and the rest was the same as in this example. Comparative Example J was formed.

When the spectral sensitivities of the electrophotographic photoreceptor of the present invention and Comparative Example (2) were measured, the results shown in FIG. 4 were obtained.

As is clear from the results shown in FIG.
It can be seen that the photosensitivity is higher on the long wavelength side of 600 nm or more compared to the above.

In addition, the photosensitivity of Comparative Example J was similar to that of this example, but on the other hand, when we followed the progress of the surface potential in the dark after charging, we found that the surface potential was higher than that of the photoreceptor of this example. It was found that the dark decay was fast, the charge was low, and the potential unevenness was large.

Furthermore, when the photoconductor of this example and Comparative Example J were left in an environment of 35°C and 95% RH for 24 hours, no change was observed in the photoconductor of this example, whereas in Comparative Example J, the substrate It was also confirmed that the film peeled off from the a-3iGe layer, and there was a problem with the adhesion of the film.

Furthermore, in producing the photoreceptor of this example, the first a-
During the formation of the 3iC layer, PH and gas were not introduced, and the other conditions were set to be exactly the same, thereby producing a negatively charged electrophotographic photoreceptor with the first a-3iC layer containing no P element. Created.

When the characteristics of this electrophotographic photoreceptor were evaluated, the spectral sensitivity on the long wavelength side of 600 nm or more was almost the same as the photoreceptor of this example, but on the other hand, compared to the photoreceptor of this example, The dark decay of the surface potential was about 20% faster, the charging was low, and the potential unevenness was large.

In producing an electrophotographic photoreceptor similar to (Example 9),
P of the first a-3iC layer 2 by changing the PH and gas flow rate.
Ten types of Alco photoreceptors shown in Table 1O were prepared with varying element contents, and the dark decay, photosensitivity, and residual potential of each photoreceptor were evaluated.

[Margin below]

No. table *marks are outside the scope of the present invention.

As is clear from the results shown in Table 10, it can be seen that photoreceptors A to A are excellent in all of dark decay, photosensitivity, and residual potential.

(Example 10) AI! 1st on the board
a-3iC layer 2, a-SiGe layer 3 and a second a-S
The iC layers 4 were sequentially laminated.

Next, the organic optical semiconductor layer 5 was formed to a thickness of 15 μm in the same manner as in (Example 8).
It was formed with

[Margin below]

In the negatively charged electrophotographic photoreceptor thus obtained,
The P element content and the total content of each 0°N element in the first a-3iC layer were measured and found to be 2,000pp each.
m, 4 at%.

Further, in producing the electrophotographic photoreceptor of this example, the first a-3iC layer and the a-3iGe layer were not formed, and the second a-3iC layer and the a-3iGe layer were not formed.
A comparative example was prepared in which only the 3iC layer was formed and the others were formed in the same manner as in this example.

Furthermore, in producing the electrophotographic photoreceptor of this example, the first a-3iC layer was not formed, but the a-3iGe layer and the second a-3iC layer were formed in the same manner, and the rest was the same as in this example. A comparative example was prepared.

When the spectral sensitivities of the electrophotographic photoreceptor of the present invention and the comparative example were measured, results similar to those shown in FIG. 4 were obtained.

In addition, the photosensitivity of the comparative example was similar to that of this example, but on the other hand, when we followed the progress of the surface potential in the dark after charging, the surface potential was higher than that of the photoreceptor of this example. It was found that the dark decay was fast, the charge was low, and the potential unevenness was large.

Furthermore, when the photoconductor of this example and the comparative example were left in an environment of 35°C and 95% RH for 24 hours, no change was observed in the photoconductor of this example, while the substrate of the comparative example It was also confirmed that peeling of the film occurred between the a-3iGe layer and the a-3iGe layer, and that there was a problem in the adhesion of the film.

Furthermore, in producing the electrophotographic photoreceptor of this example, PH, gas, and NO gas were not introduced during the formation of the first a-3iC layer, and the other conditions were set to be exactly the same, whereby the P element , the first a- which does not contain 0 element and N element
A negatively charged electrophotographic photoreceptor including a 3iC layer was produced.

When the characteristics of this electrophotographic photoreceptor were evaluated, the spectral sensitivity on the long wavelength side of 600 nm or more was almost the same as the photoreceptor of this example, but on the other hand, compared to the photoreceptor of this example, The dark decay of the surface potential was about 20% faster, the charging was low, and the potential unevenness was large.

(Example 11) In producing an electrophotographic photoreceptor similar to (Example 10), the PH3 gas flow rate and NO gas flow rate were changed, and the first a
-3 Eleven types of photoreceptors shown in Table 12 were prepared by changing the P element content and the total content of O and N elements in the iC layer, and the dark decay, photosensitivity and The residual potential was evaluated.

[Margin below]

As is clear from the results shown in Table 12, it can be seen that the photoreceptor ST is excellent in all of dark decay, photosensitivity and residual potential.

〔Effect of the invention〕

As described above, according to the present invention, high photosensitivity can be obtained over the entire visible light range, the residual potential is small, and there is little density unevenness in the image, which makes it possible to stably produce good images. A high-performance and highly reliable electrophotographic photoreceptor could be provided.

Furthermore, in the electrophotographic photoreceptor of the present invention, the film has excellent adhesion to the substrate, and reliability is also improved in this respect.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing the layer structure of the electrophotographic photoreceptor of the present invention, FIG. 3 is a diagram illustrating attenuation of surface potential, and FIG. 4 is a diagram illustrating photosensitivity with respect to wavelength. Figure 5 is a diagram showing surface potential. 2: First amorphous silicon carbide layer 3: Amorphous silicon germanium layer 4: Second amorphous silicon carbide layer Those marked with * are outside the scope of the present invention. :Organic optical semiconductor layer:Protective layer

Claims (4)

[Claims] (1) A first amorphous silicon carbide layer having an atomic composition ratio of Si_1_−_xC_x with an x value in the range of 0.2<x<0.5 is formed on the substrate, and the first amorphous silicon carbide layer is Amorphous silicon germanium layer on top, atomic composition ratio Si_1_-_yC_y
An electrophotographic photoreceptor characterized in that a second amorphous silicon carbide layer and an organic optical semiconductor layer having a y value in the range of 0<y<0.5 are sequentially laminated. (2) A first amorphous film having an atomic composition ratio of Si_1_-_xC_x in the range of 0.2<x<0.5 and containing 1 to 10,000 ppm of Group IIIa elements of the periodic table on the substrate. A silicon carbide layer is formed, and an amorphous silicon germanium layer is formed on the first amorphous silicon carbide layer, and an atomic composition ratio of Si_1_
- The second y value of _yC_y in the range 0<y<0.5
An electrophotographic photoreceptor characterized in that an amorphous silicon carbide layer and an organic photoconductor layer are sequentially laminated. (3) First amorphous silicon having an atomic composition ratio in the range of 0.2<x<0.5 in the x value of Si_1_-_xC_x and containing 5,000 ppm or less of Group Va elements of the periodic table on the substrate. A carbide layer is formed, and an amorphous silicon germanium layer is formed on the first amorphous silicon carbide layer, and an atomic composition ratio of Si_1_-_
An electrophotographic photoreceptor characterized in that a second amorphous silicon carbide layer and an organic optical semiconductor layer having a y value of yC_y in the range of 0<y<0.5 are sequentially laminated. (4) Claim (1), Claim (2), or Claim (3), characterized in that the first amorphous silicon carbide layer contains 0.01 to 30 atomic percent of oxygen and/or nitrogen. electrophotographic photoreceptor.