JPS5824148A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To improve the environmental pollution resistance, heat resistance, surface hardness, wear resistance, etc. by providing a laminated structure composed of amorphous silicon and amorphous silicon nitride formed by a glow discharge decomposition method to the potoconductor layer. CONSTITUTION:An amorphous silicon nitride film contg. a doped element such as boron is formed on a substrate of glass or the like by a glow discharge decomposition method. On the film an amorphous silicon film contg. a doped elemet is formed by a similar method to obtain a potoconductor layer having a 2-layered structure. Thus, a thin electrophotographic receptor can be manufactured, the amorphous silicon nitride film is made dense to easily attain insulation, and the manufacturing yield of electrophotographic receptors is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor whose photoconductor is amorphous silicon produced by an overlapping light lamp and glow discharge decomposition method.

Various forms of electrophotographic photoreceptors have already been investigated, but one that has been widely put into practical use is one made of selenium or 7? on a conductive substrate. : A so-called laminated photoreceptor made of haselen alloy r to a thickness of several tens of microns by vacuum evaporation, or by coating zinc oxide or cadmium sulfide together with a resin binder to a thickness of several tens of microns, for example, as described in Japanese Patent Publication No. 45-5549 No. 4. There is a so-called laminated photoreceptor in which a selenium or selenium alloy photoconductor layer has a thickness of 1 micron or less and a polyvinyl carbazole layer, which is a translucent organic semiconductor, is formed between the layers.

These photoreceptors, regardless of whether they are single or laminated, have excellent electrophotographic properties, but on the other hand, they have drawbacks such as problems in environmental pollution, heat resistance, surface creases, and abrasion resistance. Do t'*. In other words, in a photoreceptor with a selenium or selenium alloy tube photoconductor layer, when the temperature inside the copying machine increases, crystallization is promoted, and due to this thermal instability, not only does it deteriorate to an unusable state, but the selenium Toxicity to the human body A photoreceptor with strong selenium exposed on its surface is heated.As mentioned above, a photoreceptor with a laminated structure must be handled with great care in view of environmental pollution. There is also a problem of toxicity in photoreceptors that use a photoconductor layer formed by bonding zinc oxide or cadmium sulfide resin, and this type of photoreceptor also has the disadvantage of an extremely complicated manufacturing process. have Furthermore, selenium and zinc oxide have insufficient surface hardness and abrasion resistance, and cannot be used repeatedly over a long period of time in a copying machine that uses a fur brusher elastic blade as a means for removing residual toner.

The present invention has been made in view of the above facts, and provides an electrophotographic photoreceptor that is excellent in environmental pollution, heat resistance, surface hardness, abrasion resistance, etc., and has electrophotographic properties similar to or better than conventional ones. Specifically, it is an object of the present invention to provide an electrophotographic photoreceptor having a KH amorphous silicon photoconductor layer.

The present invention will now be described. As a result of searching for a photosensitive material with excellent environmental pollution and heat resistance, the present inventor discovered amorphous silicon produced by a glow discharge decomposition method, which is currently being researched and developed in the semiconductor field. (aymorpho
(hereinafter abbreviated as a-si) K, and is intended to be applied to the field of electrophotographic photoreceptors.

A-AL produced by the glow discharge decomposition method has a low density of defect levels in the energy gap, and general amorphous exhibits rather exceptional electrical properties as a semiconductor, as well as being relatively low-cost and large-area. Because of its usefulness in terms of manufacturing, which allows the production of films such as Progress is being made rapidly.

As a result of research into A-SI brass electrophotographic photosensitive materials, which are increasingly being recognized for their usefulness in the nine semiconductor application technology fields, and in particular their application as photoconductors, we have discovered that they are non-polluting, which conventional photoconductors lack. It has been found that the tube has ideal properties in terms of heat resistance, surface hardness and abrasion resistance, and electrophotographic properties sufficient to form clear images.

Substrate temperature fr approximately 5 in a-siij glow discharge decomposition method
Impurity sounds can be reduced by setting the temperature between 0℃ and 250℃.
Even when it is not contained, its volume resistivity decreases from about 1010 to 1011 as the substrate temperature f' decreases.
It has a spectral property close to that of pure A-81 IH and is excellent as a photoconductor, and its volume resistivity is 10110. When the boron content is about 90 to 160 ppm, A-61 becomes an intrinsic semiconductor, and its charge retention and dark decay rate are further improved, and it can be used as a single layer photoreceptor in the Carlson method; Furthermore, even when phosphorus is contained up to about 5 ppm, although the volume resistivity decreases, it can be used as a photoreceptor with a laminated structure;
Overall, we found that the A-61 photoreceptor is pollution-free, has excellent heat resistance, surface hardness, and abrasion resistance, and its electrophotographic properties are comparable to those of conventional photoreceptors. To explain the glow discharge decomposition method here, Fig. 1 shows a glow discharge decomposition device r for generating a-si'.
1 in the figure. Second. Third pump (1).

81H4 and PH3@Bt for +21 and +31 respectively
) T6 gas is sealed. These gases correspond to the first. Second. @3p valve adjustment i41 I 15+, +61
'j is released by opening, and its flow rate is regulated by metering valve +71 s +81 m (91 and sent to main pipe α@.Ql), (13
.

(13 is a flow meter and an a4H stop valve. The gas flowing through the main pipe 011 is sent to the reaction tube al, but a resonant vibration coil αQ is wound around this reaction tube and its own resonance The vibration power is, for example, 100 to 300 Wa.
tts is appropriate. Inside the reaction tube C19, there is a
-81 film is formed. For example, aluminum or NKSA
A glass-like substrate aη is mounted on a turntable that can be rotated by a motor αIIK, and the substrate itself is heated to a temperature of about 50 to 2.50°C by a suitable heating means. . The inside of the door of the reaction tube is in a highly vacuum state (gas pressure: α5 to 2.
orr) k is connected to the rotary pump (2) and the diffusion pump t2υ by necessity.

In the glow discharge decomposition apparatus with the above configuration, pure a-
When forming the Si film on the substrate, the first regulating valve (4)
When SiH, gas r1, or phosphorus or borium is present, the second straddle m5vI4 is adjusted, valve +5+, 161 Y 4 is opened. The amount of 0 discharged from the third pump +21, +31 is the metering pulp Cfl,
(regulated by 81, 191, 81H, gas or #
'j81H, mixed gas reaction tube a with gas, PH, and H B, E-gas! Sent to 9.

And reaction tube a! 9 inside is α5 to 2. OTorr
gas pressure, substrate temperature [50 to 250°C, and power of resonant vibration coil 100 to 300 Watts+
Together with these settings, a glow discharge occurs,
When the fed gas is only 81H4, 81H4 → 8
A pure a-81 film is produced by the reaction of 1 + 2 H, but in the case of a mixed gas, 2 (81H4+ PH1) → 281+
2F+7H.

In addition, due to the reaction of No. 8^■+B, H-→day 1+B, +5H snow, the a-Si film containing boron is approximately (lL
It is formed on the substrate aη at a rate of l to α5 microns/min.

Here, the setting of the substrate mf has a great effect on the volume resistance of the obtained a-BL film, and #1 shows a tendency for the volume resistance to decrease in proportion to the rise in substrate temperature. Accordingly, in the present invention, the substrate temperature is desirably about 50 to 250 DEG C., and an a-Si film having a maximum resistance of 103 Ω/mm can be obtained.

Furthermore, this glow waste electrolysis method can be applied to a wider range of substances, and silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, and other various substances, oxides, carbides, and indentations can be obtained. Moreover, it can be formed into an amorphous state.

When forming amorphous narrowed silicon (a-giNX), N-gas or
Due to the reaction between 'xNt gas and 5IH4. That is, 811
(, +NH, → B i N + 5 H.

Or day 1H, +N! →It seems to be a reaction of SiN+NH, etc. However, it is desirable that the substrate temperature Ifij be approximately 50 to 400 DEG C., and a maximum resistance value of 10@11 .OMEGA..multidot., which is greater than that of the a-81 film described above, can be obtained.

Examples will be described below.

Example 1 The glow discharge decomposition apparatus shown in FIG.
IH number and Na1 are decomposed and placed on an aluminum eyebrow board with a thickness of α
1 micron (D a -13i N x film is formed.

The manufacturing conditions were: gas composition f 154 SiH + N containing;
Gas, gas pressure f (L S Torr & aluminum substrate temperature t350℃, resonance dynamic power 4Q outlet wat
ts, and the film formation rate was set at α04 microns per minute. Subsequently, a purple A-81 film is deposited on the A-81 film to form a laminated structure. Substrate warm 120℃
Under a -BINx film, a 50 micron thick a
- On day 1, membrane tubes were formed. This photoreceptor sample is referred to as W (C). The photoreceptor was then charged to a surface potential of about 100 volts by corona charging and irradiated with light. The irradiation light was varied in seven steps in the wavelength range of 4,000 to 8,000 angstroms using a filter, and the sound relationship with the photocurrent was measured. The results are as shown by curve (C)- in the F1tm3 diagram, and as is clear from this, a-81 has a spectral sensitivity characteristic of about 6700 angstroms, which is close to the relative luminous efficiency, and excellent peak stability.

Next, under the same conditions, aluminum substrate J: VC20
A 30 micron thick A-81 film containing ppm boron was formed and the spectral sensitivity was measured in the same manner.The results are as shown by the curve φ)K in Figure 3, with a peak of about 6000. angstrom, which also has good spectral sensitivity characteristics.

Here, H, Sin is used to contain boron r.

Glow discharge is performed by causing a mixture of B and H gases to flow into the gas. In this case, it is important to control the molar ratio of B*'Hm/BIH+. This situation is shown in FIG. is the well-known data of W, E, Elpear,
BFi is a numerical value in this experiment.

Next, a-81 films r having thicknesses of 10.5 and 3.1 microns were formed in exactly the same manner. Furthermore, for charging tests,
Instead of the aluminum substrate, a-8iNx/a-Eli films of various types were similarly formed on Nesa glass.

Concerning these samples, author experiments and charging characteristics.

The dark decay characteristics and light decay characteristics were measured. The writing experiments are conducted using the simultaneous electromagnetic transfer method.

First, a sample having a 30 micron thick A-81 film was brought into contact with electrostatic transfer paper (manufactured by Crown Zeroback Co., Ltd.) having a dielectric layer on conductive base paper J: over the entire surface, and Nl!:
The upper part of the 8A glass substrate was connected to a negative polarity voltage source, while the transfer paper r was grounded. In this state, a voltage of 1500 volts was applied between the sample and the transfer paper from the voltage source, and at the same time image exposure was performed from the substrate side.The voltage application time was 1005 seconds, and the fog light was 80 lux/second. . (In this way, the reason why the voltage application time is short and the exposure time is high brightness darkness is because the resistance of sample E is low. Usually, for a photoreceptor with a resistance of 1010Ω・α or less, the voltage application time is H1n, ot to α001 seconds. (It is necessary to set the exposure amount to 100 to several tens of thousands of uX/sec.) The transfer paper on which the rays of light are formed is then developed by the shading brush method using a two-component developer to improve the image quality.
Although the image density f was somewhat low, the image was good overall. , similar experiment t, each thickness, $0.5,
Performed on a sample with 3.1 micron t*, t result,
With the exception of the last one with a thickness of 1 micron, ie, with a thickness of 1 micron or more, palatable images were obtained. This is a different phenomenon from the previously known fact that a thickness of 20 to 50 microns is required.

It has been revealed that the thickness of the a-St film can be reduced to 21 microns by laminating the a-131NX layer 17a-E11 film and the substrate.

Next, an experiment was conducted to investigate the charging ability, dark decay rate, and light decay rate characteristics of the sample ■■■■■■. First, an experiment on chargeability characteristics was carried out by charging each sample in the dark with a corona charger connected to 50 high voltage sources and measuring the surface potential. The characteristics of the dark decay rate were determined by leaving each charged sample tube in a dark place and measuring the decay of the surface potential. These results are as shown in FIG. 4, and the charging ability is improved in proportion to the volume resistance value. In other words, the IL-81 film (sample ■) containing 150 ppm boron formed at a plate temperature of 200°C has a volume resistivity of 8.
The surface potential charged by corona charging was approximately 400 volts due to the fact that the surface voltage was approximately 520 volts, and the surface potential of sample ■, which had a volume resistance of approximately 9×10□0 scratches, was approximately 520 volts. The resistance is a x't o□Ω・
The sample has an improved charging capacity of approximately 500 volts.

Here, ■ is 30. ■ and ■ are 10. ■ is 5. ■Vise
■ is 1 micron thick.

Next, the samples were corona-charged in the same manner as above, and the entire surface was exposed to light using a 2800 gamma tungsten lamp, and the light attenuation characteristics r of each sample were measured. As shown in FIG. 5, the results show good characteristics in all cases, with the exception of (2).

As explained above, a −SiNx #lI'(a
-S i / a -S by stacking under the -8i film
The electrophotographic photoreceptor having the i N It is valid. Also, a-11111NX
Since it is easy to form densely, it is easy to ensure insulation, and therefore manufacturing yield can also be improved.

Also, a-81NK is! The above-mentioned effect has been confirmed even with a film whose crystal pattern can be confirmed as #, and the same effect has been confirmed even with a film whose composition of a-81NXOyCz can be confirmed with an ion microanalyzer. Due to the characteristics of glow discharge decomposition, the film is hydrogenated and naturally contains Hf.

[Brief explanation of the drawing]

Figure 1 shows chromatography for producing amorphous silicon.
- Schematic diagram of the discharge dispersion device, Figure 2 shows the change in volume resistance when amorphous silicon contains boron and phosphorus, Figure 3 shows the spectral sensitivity characteristics of the amorphous silicon film, Figure 4 5 is a diagram showing the charging and dark decay characteristics of amorphous silicon, and FIG. 5 is a diagram showing the light attenuation characteristics of amorphous silicon. 111, (21, +31...1st, 2nd, 5th pump OI...main pipe al...reaction tube αe...resonant vibration coil (Lη...board and above) Applicant Suwa Seiko Co., Ltd. Agent Mogami Patent Attorney Figure 1 Figure 1 (A) Figure 3 Figure 2 Figure 5

Claims (1)

[Claims] Amorphous silicon (containing doped elements) and amorphous 9 produced by glow discharge decomposition method
An electrophotographic photosensitive member designated as IP#1, which is composed of a photoconductor layer having a two-layer laminated structure of silicon oxide (containing doped elements).