JPS59185346A - Photoconductive member - Google Patents

Abstract

PURPOSE:To obtain a photoconductive member (electrophotographic sensitive body or the like) having high sensitivity and a long life by forming a surface coating layer having a speicified specific resistance value or above and made of amorphous silicon contg. a IIIA group atom on a photoconductive layer of amorphous silicon. CONSTITUTION:A blocking layer 2 for preventing the transfer of carriers from an electrically conductive support 1 is formed on the support 1, and a B doped photoconductive layer 3 contg. at least one between H and halogen is formed on the layer 2. A surface coating layer 4 having >=10<11>OMEGAcm specific resistance and contg. C and H is then formed on the layer 3. The layer 4 is an amorphous silicon layer contg. a IIIA group atom such as B in the periodic table. Since the layer 4 is doped with a IIIA group atom such as B, the positive hole transferring rate of the layer 4 can be increased, so high sensitivity can be maintained even when the thickness of the layer 4 is increased. Thus, a photoconductive member having high electrostatic chargeability, superior surface stability and a long life is obtd.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to light (in this Mei 411 book, light refers to
It relates to a photoconductive member that is sensitive to electromagnetic waves ranging from the ultraviolet region to the gamma ray region.

[Technical background of the invention and its problems]

Due to the purpose of use, the light-conducting material that constitutes the photoconductive layer in solid-state imaging devices, electrophotographic photoreceptors, etc. has a high specific resistance in the dark (usually 1013Ωα or more, and has a low specific resistance when irradiated with light). It must have the following characteristics.

Here, taking electrophotography as an example, its principle and necessary conditions for a photoreceptor will be briefly explained. In electrophotography, the surface of a photoreceptor is charged by spreading electric charge through corona discharge. When the C2 photoreceptor is irradiated with light, pairs of electrons and holes are created, and one of them neutralizes the charge on the surface.For example, when positively charged, the pair formed by light irradiation f2 This is neutralized by electrons.Therefore, a latent image of electrostatic charge is formed on the surface of the photoreceptor due to light irradiation.Visualization is caused by the formation of a black powder called toner, which has a C2 band with an opposite sign to the charge on the surface of the photoreceptor. This is done by attracting the body to the surface of the photoreceptor by Coulomb force.At this time, even if there is no charge on the surface of the photoreceptor, the photoreceptor and developer are A measure is taken to raise the upper part of the developing device so that a market in the opposite direction to the magnetic field due to two charges occurs between the containers. This is hereinafter referred to as developing bias. The above is the principle, but the following ( 2. The conditions required for a photoreceptor are: 1. Charges charged by C nicoronal discharge are retained until light irradiation; and 2. In addition, one of them neutralizes the charge on the surface, and the other C2 reaches the support of the photosensitive layer in a short period of time.

Conventionally, a photoconductive member, such as a photoconductor, which is formed by in-coating a photoconductive layer mainly made of amorphous silicon on a conductive support, has a photoconductor that combines electric charges due to discharge f2 and electrons or positives in the photoconductive layer. In order to prevent recombination with the holes in the dark, a high resistivity surface coating layer made of amorphous silicon doped with nitrogen, carbon, or oxygen atoms is laminated on the photoconductive layer.

However, it is preferable that the surface coating layer has a larger thickness in order to protect the surface of the photoconductive layer.
As the thickness increases, ■ Sensitivity deteriorates as the energy of light reaching the photoconductive layer is attenuated; ■ Photosensitivity decreases because recombination with carriers generated from light (2) is hindered. ■ Ultraviolet region If the carrier is sensitive to (This was done with two considerations in mind,
It is an object of the present invention to provide a photoconductive member that has a long life while maintaining high sensitivity.

[Summary of the invention]

The outline of the present invention for achieving the above object is that a surface coating layer made of amorphous silicon containing C2 and 111A group atoms and having a specific resistance of 1011 Ωα or more is laminated on the photoconductive layer. This is a characteristic feature.

[Embodiments of the invention]

An embodiment of the invention will be described with reference to the drawings.

As shown in the drawings, a photoconductive member, such as a photoreceptor, which is an embodiment of the present invention, includes a support such as a conductive support, such as a drum-shaped or flat base made of aluminum, and a blocking layer 2 for preventing carrier injection from the conductive support 1; a photoconductive layer 6 made of amorphous silicon containing at least one of hydrogen atoms and halogen atoms;
A surface coating layer 4 made of amorphous silicon containing group A atoms and having a specific resistance of 10 11 Ωα or more is laminated in this order.

The blocking layer 2 is preferably formed, for example, as follows. After the conductive support 1 is installed in a vacuum reaction chamber (2), the vacuum reaction chamber is pumped for 10' to 10' by a mechanical booster pump and an oil rotary pump, for example.
The pressure was reduced to Torr, and the conductive support 1 was heated to 100 -
While heating at 400°C, a raw material gas containing silicon atoms, such as SiH4, St□H6, is introduced into the vacuum reaction chamber.
, SiF4, etc., if necessary, the source gas and the 111th gas.
Hydride or halide of group A atoms, preferably B
2H6 and/or hydrides of group VA atoms or)
A doping gas containing a 10-gunide, preferably PH3, is introduced, and the pressure inside the vacuum reaction chamber is set to 0.1-1.
maintain steady state within 'l'orr, then
Plasma is formed between the conductive support 1 and an electrode disposed opposite thereto by applying a high frequency power of, for example, 13.56 MH2, and the plasma is transferred to the surface C of the conductive support 1.
By bringing the two into contact, a blocking layer 2 can be formed. The thickness of the blocking layer 2 is 0.1 to 2
μm is preferred.

Although the doping gas may be excited with high frequency power in the vacuum reaction chamber, it is preferable to pre-excite it with electromagnetic waves, such as microwaves, introduced into the vacuum reaction chamber. This is because doping efficiency and film formation rate can be improved.

The photoconductive layer 6 is formed by introducing a raw material gas, if necessary, a mixed gas of the raw material gas and B2H6 gas at a flow rate of 1O-5 (flow rate ratio) or less with respect to the flow rate of the raw material gas into a vacuum container (= otherwise than introducing Similar to the formation of the blocking layer 2, it can be formed as a film. The thickness of the photoconductive layer B is preferably about 20 μm.

The surface coating layer 4 contains a raw material gas such as SiH4 gas and 5
The blocking layer 2 is When the flow rate of B2H6 gas is set to 1O-5 (flow rate ratio) or less C2 to the flow rate f2 of the raw material gas, the specific resistance of the surface coating layer 4 becomes 1011Ω- or more. By introducing CH4 gas, the C2 carbon atoms in the surface coating layer 4 are doped, which improves the film quality of the surface coating layer 4, such as improving the adhesion with the conductive layer 6 and reducing the occurrence of cracks. The composition of the surface coating layer doped with carbon atoms can be expressed by the first formula or the second formula.

a-(Stx(C)paHA)IX,)7. Hl,・
(1) a-(Si(C)PIIIA) IX,
) 7) Ia, gl-7,-(2) where 0<x<1
．． 0<y<1.0<z<1, and 1 (al is a halogen atom, I[IA is a group ⅠA atom).

Doping with Group 111A atoms has a specific resistance of 1011Ω
By laminating the surface coating layer 4 having a thickness of m or more on the photoconductive layer 6, it is possible to improve the film quality of the blocking layer 2 and the photoconductive layer 6 as a whole, and the surface coating layer is not doped with Group A atoms. Since the surface coating layer 4 has a large hole mobility compared to the surface coating layer 4, the sensitivity of the photoconductive member can be maintained high even if the thickness of the surface coating layer 4 is increased.

Further, the photoconductive member having the surface coating layer 4 may be used as an electrophotographic photoreceptor of an e-photograph device, and the charging ability, photosensitivity,
Lifespan (When I evaluated the performance using two, it was 5.S
The surface potential of the photoconductive member when charged by corona discharge of KV application is 500 V, the half-reduced exposure amount as photosensitivity is 0.5 lux-sec, and the lifespan is 1.
Even after repeated use a million times, no disturbance occurred in the formed image f2.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-mentioned embodiment, and can be implemented with appropriate modifications within the scope of the gist of the invention. Needless to say.

[Effects of the Invention] According to this invention f2, it is possible to provide a long-life photoconductive member that has high charging ability and photosensitivity even when the thickness of the surface coating layer is increased, and has excellent surface stability. I can do it.

[Brief explanation of the drawing]

The drawing is a partially cutaway sectional view showing an embodiment of the present invention. 1... Conductive support, 2... Blocking layer, 6
...Light guiding layer, 4... Surface coating layer. drawing

Claims (1)

[Scope of Claims] (1) In a photoconductive member in which a photoconductive layer made of amorphous silicon is formed on a support, a photoconductive layer made of amorphous silicon containing atoms of group 111A of the periodic table is provided on the photoconductive layer. The photoconductive member according to claim 1, ζ2, further comprising a coating layer having a specific resistance of 10<11 >Ω or more. (3) The photoconductive member according to claim 1 or 2, f2, wherein the group 111A atoms contained in the coating layer are boron atoms.