Abstract: An average value of a hydrogen content ratio of a surface layer made of hydrogenated amorphous carbon is set to be 0.40 or less and a maximum value of an sp2 bonding ratio in an outermost surface region of the surface layer made of the hydrogenated amorphous carbon is set to be 0.50 or less.

Abstract: The present invention provides an electrophotographic photosensitive member which has a substrate, a photoconductive layer and a surface layer formed from hydrogenated amorphous silicon carbide in this order. The average value of the carbon content (C/(C+Si)) of the surface layer formed from the hydrogenated amorphous silicon carbide is set at 0.90 or more and less than 1.00, and the average value of the hydrogen content (H/(H+C+Si)) is set at 0.40 or less; and when the average value of the ratios of the sum of a Si—O bond and an O—Si—O bond in the outermost surface region that constitutes a range within a depth of 5 nm or less from the outermost surface of the surface layer is represented by a, and an average value of the silicon content (Si/(C+Si)) is represented by b, 0.015?a*b?0.090 holds.

Abstract: An average value of a hydrogen content ratio of a surface layer made of hydrogenated amorphous carbon is set to be 0.40 or less and a maximum value of an sp2 bonding ratio in an outermost surface region of the surface layer made of the hydrogenated amorphous carbon is set to be 0.50 or less.

Abstract: Provided is an electrophotographic photosensitive member that improves the sensitivity characteristic and high-humidity deletion resistance, and achieves compatibility between a high image-resolving power and the suppression of an image memory. The electrophotographic photosensitive member comprises an electrophotographic photosensitive member, including: a photoconductive layer; and a surface layer comprising hydrogenated amorphous silicon carbide on the photoconductive layer, in which: a ratio (C/(Si+C)) of a number of carbon atoms (C) to a sum of a number of silicon atoms (Si) and the number of the carbon atoms (C) in the surface layer is 0.50 or more and 0.65 or less; a sum of an atom density of the silicon atoms and an atom density of the carbon atoms in the surface layer is 6.60×1022 atoms/cm3 or more; and a defect density of the surface layer determined by electron spin resonance measurement is 9.0×1018 spins/cm3 or more and 2.2×1019 spins/cm3 or less.

Abstract: An electrophotographic photosensitive member is disclosed which has a change layer consisting of five or more a-SiC intermediate layers, provided between an a-Si photoconductive layer and an a-SiC surface layer. Where two layers contiguous to each other in which C/(Si+C) is from 0.35 to 0.65 are selected from among the a-SiC intermediate layers included in the change layer, the rate of increase between the C/(Si+C) of an a-SiC intermediate layer on the photoconductive layer side and the C/(Si+C) of an a-SiC intermediate layer on the surface layer side (i.e., the rate of increase between layers) is 19% or less.

Abstract: An electrophotographic photosensitive member is disclosed which has a change layer consisting of five or more a-SiC intermediate layers, provided between an a-Si photoconductive layer and an a-SiC surface layer. Where two layers contiguous to each other in which C/(Si+C) is from 0.35 to 0.65 are selected from among the a-SiC intermediate layers included in the change layer, the rate of increase between the C/(Si+C) of an a-SiC intermediate layer on the photoconductive layer side and the C/(Si+C) of an a-SiC intermediate layer on the surface layer side (i.e., the rate of increase between layers) is 19% or less.

Abstract: A negatively-chargeable electrophotographic photosensitive member, has, between a cylindrical substrate and a photoconductive layer, a first lower-part layer formed of a non-single crystal material containing silicon atoms and a second lower-part layer formed of a non-single crystal material containing silicon atoms, and on its photoconductive layer has an upper-part layer formed of a non-single crystal material containing silicon atoms. The first lower-part layer is a layer containing a periodic-table Group 13 element, and the upper-part layer has a region capable of retaining electrification charges.

Abstract: Provided are a negatively-chargeable electrophotographic photosensitive member, an image forming process and an electrophotographic apparatus. The electrophotographic photosensitive member has, between its cylindrical substrate and photoconductive layer, a first lower-part layer formed of a non-single crystal material containing silicon atoms and a second lower-part layer formed of a non-single crystal material containing silicon atoms, and has, on its photoconductive layer, an upper-part layer formed of a non-single crystal material containing silicon atoms. The first lower-part layer is a layer containing a periodic-table Group 13 element, and the upper-part layer has a region capable of retaining electrification charges.

Abstract: An electrophotographic photosensitive member is provided minimizing the absorption of image exposure having a short wavelength in a surface layer and keeping good electrophotographic properties including resolving power. The electrophotographic photosensitive member includes a conductive substrate, and a photoconductive layer and a surface region layer sequentially superimposed on the conductive substrate. The surface region layer is composed of a non-single-crystal silicon nitride film containing an Group element in the periodic table and a carbon atom and using at least a silicon atom and a nitrogen atom as base materials. In the surface region layer, the Group 13 element content with respect to the total amount of constituent atoms has distribution having at least two local maximum values in the thickness direction, and an the average concentration of nitrogen atoms is 30 atm % to 70 atm %.

Abstract: To provide a high-image-quality electrophotographic photosensitive member having a high sensitivity for a wavelength close to 380 to 500 nm, remarkable image resolution property in which absorption of the wavelength is hardly recognized, working-environment characteristic and high safety and superior in abrasion resistance and fabrication easiness and reducing optical memories and an electrophotographic apparatus using the high-image-quality electrophotographic photosensitive member. In the case of an electrophotographic photosensitive member having a substrate, photoconductive layer formed on the substrate and surface layer formed on the photoconductive layer and using silicon and nitrogen atoms as base material and containing an amorphous material containing at least oxygen atoms, the surface layer contains nitrogen atoms as an average concentration shown by the following expression (1) and contains oxygen atoms by the maximum value Omax of the number of oxygen atoms in the thickness direction: 0.

Abstract: The invention provides a process for producing a negative-charging electrophotographic photosensitive member which can improve the adherence between a first layer and a second layer without lowering the effect of lessening image defects and realize a reduction in overall costs, a negative-charging electrophotographic photosensitive member produced by the process, and an electrophotographic apparatus. In the process for producing a negative-charging electrophotographic photosensitive member, a first layer is deposited on a substarte, at least the vertexes of protuberances are removed, the substrate with the first layer deposited theron is placed in a film forming furnace, the first layer surface is plasma-treated with a gas containing at least a Group 13 element in the periodic table and a dilution gas composed of at least one selected from hydrogen, argon and helium, and a layer formed of a non-single-crystal material is deposited as the second layer on the first layer.

Abstract: An electrophotographic photosensitive member is provided which can keep at a minimum the absorption of image exposure light of 380 to 500 nm in wavelength in its surface layer and concurrently can satisfactorily keep electrophotographic properties including resolving power. The electrophotographic photosensitive member has a substrate, and a photoconductive layer and a surface layer in this order provided on the substrate. The surface layer includes an amorphous material composed chiefly of silicon atoms and nitrogen atoms and containing at least oxygen atoms and carbon atoms, and the ratios of the numbers of the respective oxygen atoms, carbon atoms and nitrogen atoms to the total number of oxygen atoms, carbon atoms and nitrogen atoms contained in the amorphous material are each within a specific range.

Abstract: An electrophotographic photosensitive member is provided minimizing the absorption of image exposure having a short wavelength in a surface layer and keeping good electrophotographic properties including resolving power. The electrophotographic photosensitive member includes a conductive substrate, and a photoconductive layer and a surface region layer sequentially superimposed on the conductive substrate. The surface region layer is composed of a non-single-crystal silicon nitride film containing an Group element in the periodic table and a carbon atom and using at least a silicon atom and a nitrogen atom as base materials. In the surface region layer, the Group 13 element content with respect to the total amount of constituent atoms has distribution having at least two local maximum values in the thickness direction, and an the average concentration of nitrogen atoms is 30 atm % to 70 atm %.

Abstract: An electrophotographic photosensitive member is provided in which electrophotographic properties including resolving power have been improved with minimized absorption of image exposure light at a short wavelength in a surface layer. The electrophotographic photosensitive member includes a photoconductive layer composed of a non-single-crystal silicon film and a surface region layer composed of a non-single-crystal silicon nitride film containing silicon atoms and nitrogen atoms, superimposed on a conductive substrate. The surface region layer has a gradient-composition layer in which the composition ratio between silicon atoms and nitrogen atoms is changed and a surface layer in which the composition ratio between them is constant. The gradient-composition layer and surface region layer contain a Group 13 element, and the content distribution of the element in the thickness direction of each layer has at least one local maximum value.

Abstract: To provide a high-image-quality electrophotographic photosensitive member having a high sensitivity for a wavelength close to 380 to 500 nm, remarkable image resolution property in which absorption of the wavelength is hardly recognized, working-environment characteristic and high safety and superior in abrasion resistance and fabrication easiness and reducing optical memories and an electrophotographic apparatus using the high-image-quality electrophotographic photosensitive member. In the case of an electrophotographic photosensitive member having a substrate, photoconductive layer formed on the substrate and surface layer formed on the photoconductive layer and using silicon and nitrogen atoms as base material and containing an amorphous material containing at least oxygen atoms, the surface layer contains nitrogen atoms as an average concentration shown by the following expression (1) and contains oxygen atoms by the maximum value Omax of the number of oxygen atoms in the thickness direction: 0.

Abstract: An electrophotographic photosensitive member is provided which can keep at a minimum the absorption of image exposure light of 380 to 500 nm in wavelength in its surface layer and concurrently can satisfactorily keep electrophotographic properties including resolving power. The electrophotographic photosensitive member has a substrate, and a photoconductive layer and a surface layer in this order provided on the substrate. The surface layer includes an amorphous material composed chiefly of silicon atoms and nitrogen atoms and containing at least oxygen atoms and carbon atoms, and the ratios of the numbers of the respective oxygen atoms, carbon atoms and nitrogen atoms to the total number of oxygen atoms, carbon atoms and nitrogen atoms contained in the amorphous material are each within a specific range.

Abstract: The invention provides a process for producing a negative-charging electrophotographic photosensitive member which can improve the adherence between a first layer and a second layer without lowering the effect of lessening image defects and realize a reduction in overall costs, a negative-charging electrophotographic photosensitive member produced by the process, and an electrophotographic apparatus. In the process for producing a negative-charging electrophotographic photosensitive member, a first layer is deposited on a substarte, at least the vertexes of protuberances are removed, the substrate with the first layer deposited theron is placed in a film forming furnace, the first layer surface is plasma-treated with a gas containing at least a Group 13 element in the periodic table and a dilution gas composed of at least one selected from hydrogen, argon and helium, and a layer formed of a non-single-crystal material is deposited as the second layer on the first layer.