US4853309A
Expired / Lapsed
US
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Photoreceptor for electrophotography with a-Si layers having a gradient concentration of doped atoms and sandwiching the photoconductive layer therebetween
Assignee: Sharp Corp
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Filing: 1988-06-03
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Granted: 1989-08-01
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Expires: 2008-06-03
Abstract
Abstract A photoreceptor for electrophotography including an electrically conductive substrate, a bottom layer, a photoconductive layer composed mainly of amorphous silicon, and a surface layer, in that order. Both the bottom and surface layers have a greater optical bandgap than said photoconductive layer. A first middle layer is disposed between said bottom layer and said photoconductive layer, and a second middle layer is disposed between said photoconductive layer and said surface layer. Both the first and second middle layers are composed mainly of amorphous silicon and have a concentration of doped atoms which varies from the bottom to the top of the layer.
Inventors
- 👤 Takashi Hayakawa
- 👤 Hideo Nojima
- 👤 Yoshimi Kojima
- 👤 Shiro Narikawa
- 👤 Toshiro Matsuyama
- 👤 Eiji Imada
- 👤 Shaw Ehara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:00
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/08; G03G5/082; G03G5/08214; G03G5/0825; G03G5/08257
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
104 words
A photoreceptor for electrophotography comprising an electrically conductive substrate, a bottom layer, a photoconductive layer composed mainly of amorphous silicon, and a surface layer, in that order, both the bottom and surface layers having a greater optical bandgap than said photoconductive layer, wherein a first middle layer is disposed between said bottom layer and said photoconductive layer, and a second middle layer is disposed between said photoconductive layer and said surface layer, both the first and second middle layers being composed mainly of amorphous silicon and having a varied distribution of concentrations of doped atoms from the bottom to the top of the layer.
Claim 2
Dependent Claim
104 words
A photoreceptor for electrophotography comprising an electrically conductive substrate, a bottom layer, a photoconductive layer composed mainly of amorphous silicon, and a surface layer, in that order, both the bottom and surface layers having a greater optical bandgap than said photoconductive layer, wherein a first middle layer is disposed between said bottom layer and said photoconductive layer, and a second middle layer is disposed between said photoconductive layer and said surface layer, both the first and second middle layers being composed mainly of amorphous silicon and having a varied distribution of concentrations of doped atoms from the bottom to the top of the layer.
Claim 3
Dependent Claim
31 words
A photoreceptor for electrophotography according to claim 1, wherein said photoconductive layer contains boron, the concentration of which is not uniform therethrough from the bottom to the top of the layer.
Claim 4
Dependent Claim
26 words
A photoreceptor for electrophotography according to claim 1, wherein said surface layer and said bottom layer are composed of amorphous silicon nitride or amorphous silicon carbide.
Claim 5
Dependent Claim
53 words
A photoreceptor for electrophotography according to claim 3, wherein said surface layer and said bottom layer are composed of amorphous silicon nitride, and said first and second middle layers contain nitrogen and boron as doped atoms, the concentrations of which are not uniform therethrough from the bottom to the top of the layer.
Claim 6
Dependent Claim
53 words
A photoreceptor for electrophotography according to claim 3, wherein said surface layer and said bottom layer are composed of amorphous silicon carbide, and said first and second middle layers contain carbon and boron as doped atoms, the concentrations of which are not uniform therethrough from the bottom to the top of the layer.
Claim 7
Dependent Claim
26 words
A photoreceptor for electrophotography according to claim 2, wherein said surface layer and said bottom layer are composed of amorphous silicon nitride or amorphous silicon carbide.
Claim 8
Dependent Claim
111 words
A photoreceptor for electrophotography comprising: an electrically conductive substrate; a bottom layer disposed on said substrate; a first middle layer disposed on said bottom layer; a photoconductive layer composed mainly of amorphous silicon disposed over said first middle layer; a second middle layer disposed over said photoconductive layer; and a surface layer disposed over said second middle layer; said bottom layer and said surface layer having a greater optical bandgap than said photoconductive layer; said first and second middle layer being composed mainly of amorphous silicon with doped atoms, the concentration of doped atoms in each of said middle layers varying with the distance within said layer from said photoconductive layer.
Claim 9
Dependent Claim
111 words
A photoreceptor for electrophotography comprising: an electrically conductive substrate; a bottom layer disposed on said substrate; a first middle layer disposed on said bottom layer; a photoconductive layer composed mainly of amorphous silicon disposed over said first middle layer; a second middle layer disposed over said photoconductive layer; and a surface layer disposed over said second middle layer; said bottom layer and said surface layer having a greater optical bandgap than said photoconductive layer; said first and second middle layer being composed mainly of amorphous silicon with doped atoms, the concentration of doped atoms in each of said middle layers varying with the distance within said layer from said photoconductive layer.
Claim 10
Dependent Claim
26 words
The photoreceptor of claim 7, wherein said photoconductive layer includes a concentration of doped atoms which varies as the distance from said second middle layer increases.
Claim 11
Dependent Claim
28 words
The photoreceptor of claim 8, wherein the doped atoms in said photoconductive layer comprise boron, the concentration of boron increasing with increasing distance from said second middle layer.
Claim 12
Dependent Claim
26 words
A photoreceptor for electrophotography according to claim 2, wherein said surface layer and said bottom layer are composed of amorphous silicon nitride or amorphous silicon carbide.
Claim 13
Dependent Claim
26 words
A photoreceptor for electrophotography according to claim 7, wherein said surface layer and said bottom layer are composed of amorphous silicon nitride or amorphous silicon carbide.
Claim 14
Dependent Claim
26 words
A photoreceptor for electrophotography according to claim 8, wherein said surface layer and said bottom layer are composed of amorphous silicon nitride or amorphous silicon carbide.
Claim 15
Dependent Claim
41 words
The photoreceptor of claim 8, wherein the doped atoms in said photoconductive layer comprise boron; said surface layer and said bottom layer being composed of amorphous silicon nitride; said first and second middle layers containing nitrogen and boron as doped atoms.
Claim 16
Dependent Claim
30 words
The photoreceptor of claim 13, wherein the concentration of nitrogen and boron in each of said first and second middle layers increases as the distance from said photoconductive layer increases.
Claim 17
Dependent Claim
41 words
The photoreceptor of claim 8, wherein the doped atoms in said photoconductive layer comprise boron; said surface layer and said bottom layer being composed of amorphous silicon carbide; said first and second middle layers containing carbon and boron as doped atoms.
Claim 18
Dependent Claim
30 words
The photoreceptor of claim 15, wherein the concentration of carbon and boron in each of said first and second middle layers increases as the distance from said photoconductive layer increases.
Claim 19
Dependent Claim
58 words
The photoreceptor of claim 9, wherein the doped atoms in said first and second middle layer comprise (1) boron and (2) nitrogen or carbon, and wherein said photoconductive layer, said first middle layer and said second middle layer are prepared by a glow-discharge decomposition method, a plasma chemical vapor deposition method, a membrane-formation method, or a sputtering technique.
Claim 20
Dependent Claim
67 words
The photoreceptor of claim 17, wherein the doped atoms in said first and second middle layer comprise boron and nitrogen, and wherein said photoconductive layer, said first middle layer and said second middle layer are prepared under membrane-formation conditions during which boron and nitrogen gas flow rates are changed continuously or in a stepwise fashion so as to vary the concentration of boron and nitrogen doped atoms.
Claim 21
Dependent Claim
58 words
The photoreceptor of claim 10, wherein the doped atoms in said first and second middle layer comprise (1) boron and (2) nitrogen or carbon, and wherein said photoconductive layer, said first middle layer and said second middle layer are prepared by a glow-discharge decompositon method, a plasma chemical vapor deposition method, a membrane-formation method, or a sputtering technique.
Claim 22
Dependent Claim
67 words
The photoreceptor of claim 19, wherein the doped atoms in said first and second middle layer comprise boron and nitrogen, and wherein said photoconductive layer, said first middle layer and said second middle layer are prepared under membrane-formation conditions during which boron and nitrogen gas flow rates are changed continuously or in a stepwise fashion so as to vary the concentration of boron and nitrogen doped atoms.
Claim 23
Dependent Claim
24 words
The photoreceptor of claim 14, wherein the concentration of boron in said photoconductive layer continuously increases with increasing distance from said second middle layer.
Claim 24
Dependent Claim
27 words
The photoreceptor of claim 14, wherein the concentration of boron in said photoconductive layer increases in a stepwise manner with increasing distance from said second middle layer.
Claim 25
Dependent Claim
24 words
The photoreceptor of claim 16, wherein the concentration of boron in said photoconductive layer continuously increases with increasing distance from said second middle layer.
Claim 26
Dependent Claim
27 words
The photoreceptor of claim 16, wherein the concentration of boron in said photoconductive layer increases in a stepwise manner with increasing distance from said second middle layer.
Claim 27
Dependent Claim
42 words
The photoreceptor of claim 22, wherein the concentration of nitrogen increases in a stepwise manner and the concentration of boron increases in a continuous manner in each of said first and second middle layers as the distance from said photoconductive layer increases.
Claim 28
Dependent Claim
42 words
The photoreceptor of claim 24, wherein the concentration of nitrogen increases in a stepwise manner and the concentration of boron increases in a continuous manner in each of said first and second middle layers as the distance from said photoconductive layer increases.
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