Patent ID: 9588447
Date: 2017-03-07
CPC Classifications: G03G

Claim:
1. An electrophotographic photosensitive member to be negatively electrified, comprising: a conductive substrate; a photoconductive layer on the conductive substrate, the photoconductive layer being formed from hydrogenated amorphous silicon; and a surface layer on the photoconductive layer, the surface layer being formed from hydrogenated amorphous silicon carbide, wherein the surface layer has a change region in which a ratio (C/(Si+C)) of the number of carbon atoms (C) with respect to the sum of the number of silicon atoms (Si) and the number of carbon atoms (C) gradually increases toward a surface side of the electrophotographic photosensitive member from a side of the photoconductive layer, the change region having an upper charge injection prohibiting portion containing a Group 13 atom, and a surface-side portion positioned closer to the surface side of the electrophotographic photosensitive member than the upper charge injection prohibiting portion and not containing the Group 13 atom, wherein when a precipitous property of the distribution of the Group 13 atom in the surface layer is defined as ΔZ, ΔZ satisfies a relationship represented by the following expression (A7), wherein ΔZ is determined as follows: (A1) obtaining a depth profile of the surface layer of the electrophotographic photosensitive member by an SIMS analysis; in the depth profile, defining an ionic strength of the Group 13 atom in the thickness direction of the surface layer as f(D), defining a maximal value of f(D) as f(D defining a second order differential of f(D) as f″(D), defining a distance from the surface of the electrophotographic photosensitive member to a first position at which the following relation is satisfied in the surface layer as D f″(D) changes from f″(D)=0 to f″(D)<0 defining a distance from the surface of the electrophotographic photosensitive member to a second position at which the following relation is satisfied in the surface layer as D f″(D) changes from f″(D)<0 to f″(D)=0 defining a distance from the surface of the electrophotographic photosensitive member to a third position which satisfies f((D defining the ionic strength f(D) at their position, as f(D when f(D defining a fourth position at which the ionic strength first reaches 16% with respect to the standard ionic strength, and defining a fifth position at which the ionic strength first reaches 84% with respect to the standard ionic strength, ΔZ is determined as a distance between the fourth position and the fifth position, and wherein the ΔZ (A2) providing a standard laminated film A consisting of a film A (A3) obtaining a depth profile of the surface layer of a standard laminated film A by an SIMS analysis in the depth profile, defining f(D), f(D defining a sixth position at which the ionic strength first reaches 16% with respect to the standard ionic strength of the standard laminated film A, and defining a seventh position at which the ionic strength first reaches 84% with respect to the standard ionic strength of the standard laminated film A, ΔZ