JPH0117572B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an electrophotographic photoreceptor.

One of the conventional photoreceptors for electrophotography is made by depositing a Se film on a conductive substrate such as aluminum using a vacuum evaporation method, and such Se photoreceptor has a low spectral sensitivity.
It has a wavelength of only around 500 nm, and is unstable and easily crystallized. In order to improve the stability of this Se photoreceptor, there is a Se--As photoreceptor in which a small amount of As is added to Se.

In addition, we have also developed Se, which has extended spectral sensitivity to longer wavelengths.
There is a Se-Te photoreceptor made by adding Te (tellurium), but as the amount of Te added increases, the electrical resistance of the Se-Te film decreases, resulting in poor surface charge retention properties, and in fact It can no longer be used as a photoreceptor.

Furthermore, Se-Bi alloy photoreceptors made by adding Bi to Se have low sensitivity at long wavelengths, and Se-Bi-I alloy photoreceptors made by adding I (iodine) to these have low spectral sensitivity. is known to have sufficiently high sensitivity even at 800 nm. However, such photoreceptors require a special flash deposition method to form the Se-Bi-I alloy film (for example,
49-104594), but also the resulting alloy film was unstable, making it difficult to put the Se-Bi-I alloy photoreceptor into practical use.

For example, FIG. 4 shows an example of such a method, in which 11 is an aluminum substrate, 12 is a crucible, 13 is a material supply device, and 14 is a vacuum chamber. That is, a method of preparing a Se-Bi-F mixture in advance, pulverizing it into fine particles, supplying it little by little to the heating crucible 2, evaporating the supplied amount in a short time, and vacuum-depositing it on the aluminum substrate 1. It is. However, although this method requires a homogeneous mixture of Se--Bi--F, it is difficult to make this mixture itself, and even if this mixture is obtained, it is very difficult to control the supply of the mixture.

Next, FIG. 4 shows a three-temperature method using a vacuum evaporation method. Three types of materials, Se, Bi, and BiF _3, are placed separately in three crucibles 2, and the temperature of each crucible 2 is controlled to the optimum temperature using a thermocouple (not shown), etc., and the amount of evaporation of each is controlled. It is something that we try to control. However, in this case as well, it takes a considerable amount of time for each temperature to reach a constant temperature and for the amount of evaporation to become constant, and evaporation of the material during that time is unavoidable. In addition, it is difficult to control the composition of the deposited film only by controlling the temperature of the crucible 2. For example, if a shutter 15 is provided,
It was necessary to control the amount of evaporation by adjusting the opening.

That is, all of these methods have had difficult problems that have not been solved in practice.

On the other hand, laser beam printers using the electrophotographic photoreceptor mentioned above currently use 633n as a light source.
A He--Ne laser with a wavelength of m is used. Recently, attempts have been made to use semiconductor lasers as light sources, and the wavelength of such light sources has been
700 to 900 nm, and photoreceptors with high sensitivity and high charge retention ability at longer wavelengths are increasingly required.

The present invention has been made by focusing on the above points,
Conventionally, it has been difficult to add F as a component of the alloy to the above-mentioned Se-Bi alloy system because it is highly corrosive, corroding silica glass, and is highly toxic and difficult to handle. We provide a new method that enables the formation of a Se-Bi-F alloy film by easily adding Se-Bi-F, and this provides a photoresist film with sufficiently high sensitivity in the long wavelength range and high stability for electrophotography. The purpose is to provide a photoreceptor.

Embodiments of the present invention will be described below with reference to the drawings.

In Fig. 1, 1 is an aluminum substrate supported by a support 5, 2 is a target made of Se-Bi-F mixed powder, and 3 is a quartz dish, which are placed in a vacuum chamber 4 and exposed to a vacuum atmosphere. It is maintained.

Pre-prepared Se-Bi alloy powder and
Put BiF ₃ powder in a glass ball mill, add methanol, and ball mill for about 24 hours.
A pulverized mixture of this is placed in a quartz dish 3 and used as a target 2. By the sputtering method, in which the target 2 is placed on the lower side and the substrate 1 is placed on the upper side as shown in the figure, and sputtered, the sputtered atoms are uniformly mixed in space, and these atoms are mixed uniformly on the aluminum substrate. 1 to form a Se-Bi-F alloy film on the substrate surface. This is processed into a photoresist film to obtain a desired electrophotographic photoreceptor. It should be noted that a conventionally used high frequency sputtering device can be used for the sputtering method.

Regarding the composition of the SE-Bi-F alloy film, Bi
40g of Se-Bi alloy powder containing 2.0 atomic percent of
and 0.4 g of BiF ₃ powder were placed in the glass ball mill, thoroughly mixed and pulverized, and used as a target with Se as 96.8 atomic percent, Bi as 2.3 atomic percent, and F as 0.9 atomic percent, and the photoresist film thickness was
It was 50 μm. Note that the substrate temperature was 50°C.

Next, in the same manner as above, a mixed powder similar to the first example described above containing 40 g of Se-Bi alloy powder containing 2.0 atomic percent Bi and 0.4 g of BiF ₃ powder was prepared.
0.4 g of As powder was added and the same manufacturing process as described above was carried out to obtain an aluminum substrate 1 having a photoresist film with a thickness of 40 μm. Note that the substrate temperature at this time was 60°C.

When the composition of the alloy film obtained by sputtering in the above manufacturing method of the present invention was analyzed, it was found that it was almost the same as the composition of the sputtering target powder, and a stable photoresist film could be easily obtained with this alloy film. Ta. Next, FIG. 2 shows another embodiment, in which the substrate 1 is formed into a drum-shaped body 1', and sputtering can also be applied to this in the same manner.

Example 1 The composition ratio of the Se-Bi-F alloy film was 97 atomic percent Se, 2 atomic percent Bi, and 1 atomic percent F, and the film was sputtered to a thickness of 50 μm.
An alloy film was created on the substrate.

The obtained Se-Bi-F alloy photoreceptor has sufficiently high spectral sensitivity up to 850 nm, for example, the half-decreased exposure amount at 800 nm is 0.4 μJ/cm ² and the surface potential is
720V, and the residual potential was as small as 30V, which is sufficient for practical use.Moreover, the photoresist film showed high stability without any crystallization or cracking.

When this method was carried out using targets with various compositions, it was found that the composition of the Se-Bi-F alloy film was 0.5-10 atomic percent Bi, 0.01-10 atomic percent Bi,
Good properties were shown when F was 10 atomic percent and the balance was Se.

Figure 3 shows the sensitivity characteristics of the Se-Bi-F alloy photoreceptor.
The half-decreased exposure amount (μJ/cm ² ) is illustrated using the composition ratio of Bi and F as a variable.

As shown in the shaded area in the same figure, in the case of 1 to 5 atomic percent Bi and 0.5 to 4 atomic percent F,
The half-decrease exposure amount at 800 nm was 0.5 μJ/cm ² or less, showing extremely good sensitivity characteristics.

Example 2 This is a case where As is added to the Se-Bi-F alloy film. As a powder target for the high-frequency sputtering device, a powder target with a composition ratio of 95.8 atomic percent of Se, 2.2 atomic percent of Bi, 0.9 atomic percent of F, and 1.1 atomic percent of As was used, and a photosensitive material with a thickness of 40 μm was prepared in the same manner as above. A membrane was obtained. The half-decrease exposure amount at 800 nm of this Se-Bi-F alloy photoreceptor with As added is 0.6 μJ/cm ² , which is slightly worse than that without As added, but it has higher surface hardness and thermal stability. This further improved reliability as a photoreceptor.

As explained above, according to the method for manufacturing an electrophotographic photoreceptor according to the present invention, the Se-Bi alloy and
Using a mixed powder with BiF ₃ as a target, F can be easily added to the Se-Bi alloy by sputtering without considering the high corrosivity and strong toxicity mentioned above, and the Se-Bi-F alloy film can be applied to a conductive substrate. As a result, electrophotographic photoreceptors with high spectral sensitivity can be produced stably and inexpensively, and furthermore, the composition of the desired photoresist film can be roughly matched to the composition of the mixed powder target by the sputtering. This has the effect that the composition of the photoresist film described above can be controlled very easily.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams showing an embodiment of the electrophotographic photoreceptor manufacturing method according to the present invention, and FIG. 3 is a Se-
Sensitivity characteristics diagram of Bi-F alloy photoreceptor, Figures 4 and 5
The figure is an explanatory diagram showing a conventional method of forming a Se-Bi-F alloy film. 1...Alumina substrate, 2...Target, 4...
...vacuum chamber.

Claims (1)

[Claims] 1 Consists of a step of preparing a conductive substrate and a photoresist film forming step of forming a photoresist film on the conductive substrate, the photoresist film forming step using a powder target consisting of Se-Bi alloy powder and BiF ₃ powder. A method for manufacturing an electrophotographic photoreceptor, characterized in that a film is formed on the conductive substrate by a high-frequency sputtering method.