JPS5997149A - Amorphous silicon photoreceptor - Google Patents

Abstract

PURPOSE:To prevent a copied image from blurring, to enhance surface potential retentivity, and to eliminate fatigue effect by forming a high resistance layer made of a specified amorphous silicon in an amorphous silicon photoreceptor for use in an electrophotographic copying machine etc. CONSTITUTION:An amorphous silicon layer 2 contg. H sandwiched with high resistance layers 1, 3 is formed on the substrate 4 of the photoreceptor. The layers 1, 3 are composed of an amorphous silicon having carbon combining with one atom of silicon per one atom of carbon, and H. Said layers 1, 3 are formed, e.g., by carrying out glow discharge of <=25 W high frequency power in a gas mixture of SiH4 and lower alkane such as CH4, and bringing the obtained plasma into contact with the surface of the substrate 4. The use of the photoreceptor thus obtained prevents blurring and bleeding of a copied image, enhances the surface potential retentivity, and almost eliminates fatigue effect.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention is based on the technical field of photoreceptors that can be used, for example, in electrophotographic copying machines.

[Technical background of the invention and its problems]

Conventionally, an amorphous silicon photoreceptor used in an electrophotographic copying machine (2) has a photoreceptor base layer (2) a hydrogen-containing amorphous silicon layer sandwiched between high-resistance layers; molecules and CH4
The carbon atoms in the amorphous silicon are bonded between silicon atoms (double bonds, so to speak, forming a bond network of silicon atoms). (2) It is completely absorbed.

Therefore, with conventional amorphous silicon photoreceptors, the carriers generated in the amorphous silicon layer cannot completely migrate to the photoreceptor base layer or the surface of the amorphous photoreceptor due to light irradiation (2), so complex line drawings and characters cannot be drawn. It is not possible to make clear copies.In other words, conventional amorphous silicon photoreceptors have a large decrease in surface potential retention over time and also have poor fatigue properties.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The object of the present invention is to provide an amorphous silicon photoreceptor that has no blurring or blurring of copied images, has a high surface potential retention rate, and has little fatigue effect despite repeated charging and exposure.

[Summary of the invention]

The outline of the present invention for achieving the above object is to provide a high resistance layer sandwiching an amorphous silicon layer containing at least hydrogen so that carriers generated in the amorphous silicon layer can move to the surface of the photoreceptor (-51 It is characterized by being composed of amorphous silicon having carbon and hydrogen that bond one silicon atom per atom.

[Embodiments of the invention]

The layer structure of the amorphous silicon photoreceptor according to the present invention is as shown in FIG. It is made up of three layers.

7 The amorphous silicon layer 2 is similar to that in conventional amorphous silicon photoreceptors.

The high resistance layers 1 and 3 are formed of amorphous silicon having carbon and hydrogen bonding one atom of silicon per atom of carbon. The silicon atoms in the amorphous silicon are, for example, CH3 groups, CH3C112 groups, CH
It has a lower alkyl group such as a 3CH2CH2 group, preferably a CH3 group, and the content of carbon having a bonding mode such as 5i-CH2-8+ is negligible. In addition, the infrared absorption spectrum of the amorphous silicon determined by an infrared spectrophotometer shows that the amorphous silicon has a
I-CH3,5I-cH2cI (3, st -CH2
CH2CH3 can be identified. The high resistance layers 1 and 3 made of amorphous silicon are made of SiH4, for example.
and a lower alkane such as CH4 at 25W.
A glow discharge of high frequency power is performed as described below, and the surface of the hydrogen-containing amorphous silicon layer 2 formed through the anti-layer 1 is brought into contact with the surface (from the second point, it is possible to form a layer).

Next, in C2, an experimental example of the present invention will be specifically explained.

Example S tH4758CCM and CH4/SiH4 flow rate ratio is 2
Q, 4'l' to the mixed gas with CH4 gas which is 00%
Under pressure of orr, while heating for 220 tl'l, 25
A glow discharge of high frequency power of W (2) is performed to form a plasma, and the plasma is applied to the surface of the photoreceptor substrate (21).
0 minutes of contact (2, therefore, the surface of the photoreceptor substrate (
A first high resistance layer having a thickness of approximately 300 AI was formed.

Next, the 8iH4180SCCM was heated to 220C1 under a pressure of 0.5 Torr while glow discharged with a high frequency power of 25W to form a plasma, and the plasma was applied to the surface of the first high resistance layer (=5 hours). A hydrogen-containing amorphous silicon layer having a thickness of about 15 μm was formed on the first high-resistance layer.

Thereafter, under the same conditions as for forming the first high-resistance layer, about 30% of C1 is deposited on the hydrogen-containing amorphous silicon layer.
A second high resistance layer with a thickness of 0x was formed.

As described above, an amorphous silicon photoreceptor having three layers formed on the photoreceptor substrate was obtained.

FIG. 2 shows the infrared absorption spectra of the first and second high resistance layers. As shown in Figure 2, C2, 81-CH2-
There is no absorption peak based on the C-H bond (=) in the bonding mode of 8i, and there is a large absorption peak based on 5l-CH3. This means that the amorphous silicon in the high resistance layer (: This indicates that carbon atoms are not incorporated, or even if they are incorporated, the amount is negligible.

The amorphous silicon photoreceptor (=negatively charged) obtained as described above (-1) was as shown in Figure 3 (
The surface potential was ranked No. 1 with a knee of 600 V, and even after 15 seconds had passed after being negatively charged, the surface potential remained at the original value of 60 V or more, and the surface potential retention rate was extremely good. Also,
The amorphous silicon photoreceptor obtained as above is
2 A'ux tungsten light irradiation (= vs. 0.7
It showed high sensitivity of JS. Furthermore, as shown in Fig. 4, the amorphous silicon photoconductor obtained in the above C2 process has a very good surface area despite repeated charging and exposure. No decrease in potential A or increase in residual potential B was observed.As described above (
When a document with complicated line drawings was copied using an electronic copying machine equipped with the amorphous silicon photoreceptor obtained in this way, no pockets or smudges occurred in the copied image.

〔Effect of the invention〕

According to the present invention, it is possible to provide an excellent amorphous silicon photoreceptor that has no blurring or blurring in copied images, has a high surface potential retention rate, and has almost no fatigue effect despite repeated charging and exposure. .

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view showing an embodiment of the present invention, FIG. 2 is a spectrum chart showing an infrared absorption spectrum of amorphous silicon, which is a high resistance layer in an embodiment of the invention, and FIG. (Characteristic diagram showing the surface potential retention characteristics of the amorphous silicon photoconductor according to the second aspect, and
The figure is a characteristic diagram showing the fatigue characteristics of the amorphous silicon photoreceptor according to the present invention. 1.3... High resistance layer, 2... Hydrogen-containing amorphous silicon layer, 4... Photoreceptor substrate. Agent Patent Attorney Masayoshi Misawa I-i!i-
Between (5ee) Koji-F1 school

Claims (4)

[Claims] (1) In an amorphous silicon photoreceptor C2 having a photosensitive layer formed by sandwiching an amorphous silicon layer containing at least hydrogen between high-resistance layers, 1 silicon per atom is used.
An amorphous silicon photoreceptor in which a high resistance layer is formed of amorphous silicon containing carbon and hydrogen that bond atoms. (2) The high-resistance layer is made of CH3, which is produced from a mixed gas containing silicon atom-containing molecules and carbon atom-containing molecules.
2. The amorphous silicon photoreceptor according to claim 1, wherein the amorphous silicon photoreceptor is formed in a plasma state in which the content of radicals is greater than the content of C)I radicals. (3) The amorphous silicon photoreceptor according to claim 1 or 2 C, wherein the plasma state is caused by discharging the mixed gas at 25 W or less. (4) The amorphous silicon photosensitive layer according to any one of claims 1 to 6, characterized in that the high-resistance layer contains CH3 radicals that can be detected by an infrared spectrophotometer. body.