A photosensitive layer of an electrophotographic photosensitive member is a single layer and contains a charge generating material, a hole transport material, a first electron transport material, a second electron transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin includes repeating units (1), (2), (3), and (4).

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A percentage of the number of repeats of the repeating unit (3) relative to the total of the number of repeats of the repeating units (1) and the number of repeats of the repeating unit (3) is greater than 0% and less than 20%. The first electron transport material includes a compound represented by formula (A15) or (A16).

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The second electron transport material includes a compound represented by formula (B10), (B11), (B12), (B13), or (B14)

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A single-layer photosensitive layer included in an electrophotographic photosensitive member contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin includes repeating units represented by formulas (1), (2), (3), and (4).

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The percentage of the number of repeats of the repeating unit represented by formula (3) relative to a total of the number of repeats of the repeating unit represented by formula (1) and the number of repeats of the repeating unit represented by formula (3) is greater than 0% and less than 20%.

Provided are an electrophotographic photosensitive member which satisfies wear resistance and electrical characteristics, and in which image deletion is satisfactorily suppressed, and a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member. The electrophotographic photosensitive member comprises a surface layer which includes a polymerized product of a hole transporting substance having a reactive functional group, in which a structure other than the reactive functional group of the hole transporting substance is one of: a structure consisting of a carbon atom and a hydrogen atom; and a structure consisting of a carbon atom, a hydrogen atom and an oxygen atom, and the structure other than the reactive functional group of the hole transporting substance comprises a specific conjugate structure.

An electrophotographic photoreceptor includes at least a photosensitive layer and a protective layer sequentially layered on a conductive support, wherein the protective layer contains a cured product of a curable composition containing p-type semiconductor fine particles, an n-type organic semiconductor, and a polymerizable compound.

An electrophotographic photosensitive member includes a laminated body, the laminated body including a support, an undercoat layer, and a charge generating layer. The undercoat layer includes a polymerized product of a composition including an electron transport material represented by formula (1), a cross-linking agent, and a thermoplastic resin having a polymerizable functional group, the laminated body satisfying expressions (2) and (3)
Z.sup.1—X—Z.sup.2  (1)
0.20≦|Vd2−Vd1|≦2.0  (2)
τ≦10  (3)
in which Z.sup.1 and Z.sup.2 are groups having electron transport property, X is a linker, Vd2 and Vd1 are surface potentials of the charge generating layer after charging and τ is transit time based on a change rate of the surface of the charge generating layer, each as defined in the specification.

An electrophotographic photoreceptor includes a conductive support, an undercoat layer on the conductive support, and a charge generation layer on the undercoat layer, in which the charge generation layer contains a phthalocyanine compound, the undercoat layer contains an electron transport compound, and a difference between an energy level of the lowest unoccupied molecular orbital of the phthalocyanine compound and an energy level of the lowest unoccupied molecular orbital of the electron transport compound is less than 0.45 eV.

An electrophotographic photoreceptor includes a conductive support; and an undercoat layer and a photosensitive layer stacked on the conductive support, in which the undercoat layer contains crystalline electron transport compound particles. In X-ray diffraction measurement performed on the undercoat layer in a thickness direction, a maximum intensity peak has a half-width of 5° or less, and a maximum value Nmax among orientation indices N expressed by equation (1) below is 1 or more and 3 or less:

[00001]$\begin{array}{cc}\text{Orientation index}\text{=}\frac{l_1}{\frac{{\displaystyle .Math.l_1}}{\frac{l_2}{{\displaystyle .Math.l_2}}}}& \text{­­­(1)}\end{array}$

where I.sub.1 represents a relative integral intensity of each of peaks in the X-ray diffraction measurement performed on the undercoat layer in the thickness direction, and I.sub.2 represents a relative integral intensity of each of peaks in X-ray diffraction measurement performed on the undercoat layer processed into a powder form having a volume-average particle diameter of 5 .Math.m or less.

An electrophotographic photoreceptor, including a photosensitive layer formed on an electroconductive substrate. The photosensitive layer includes a charge-generating material and an electron-transporting material, and the electron-transporting material includes first and second electron-transporting materials. A difference in lowest unoccupied molecular orbital (LUMO) energy between the first electron-transporting material and the charge-generating material is in a range from 1.0 to 1.5 eV, and a difference in LUMO energy between the second electron-transporting material and the charge-generating material is in a range from 0.6 to 0.9 eV. A ratio of mass of the second electron-transporting material to a total of mass of the first electron-transporting material and the mass of the second electron-transporting material is in a range from 3 to 40%.

Provided is an electrophotographic photosensitive member that suppresses image smearing at the time of its repeated use, and expresses satisfactory wear resistance and electric characteristics. The electrophotographic photosensitive member includes a support and a photosensitive layer in the stated order, wherein a surface layer of the electrophotographic photosensitive member contains a copolymer of a hole-transportable compound having a chain-polymerizable functional group and a specific compound having maleimide groups.

An electrophotographic photoreceptor, including a photosensitive layer formed on an electroconductive substrate. The photosensitive layer includes a charge-generating material and an electron-transporting material, and the electron-transporting material includes first and second electron-transporting materials. A difference in lowest unoccupied molecular orbital (LUMO) energy between the first electron-transporting material and the charge-generating material is in a range from 1.0 to 1.5 eV, and a difference in LUMO energy between the second electron-transporting material and the charge-generating material is in a range from 0.6 to 0.9 eV. A ratio of mass of the second electron-transporting material to a total of mass of the first electron-transporting material and the mass of the second electron-transporting material is in a range from 3 to 40%.