Electrophotographic photosensitive member, process cartridge, and image forming apparatus

An electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer, wherein

• the photosensitive layer is a single-layer photosensitive layer,
• the photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin,
• the charge generating material is a phthalocyanine pigment,
• a content percentage of the phthalocyanine pigment relative to a mass of the photosensitive layer is at least 0.70% by mass and no greater than 0.92% by mass,
• the hole transport material is represented by a chemical formula (HTM-1) or (HTM-2),
• a film thickness of the photosensitive layer is at least 28 μm and no greater than 32 μm,
• a charge amount difference ΔQ of a surface of the photosensitive layer is no greater than 6.50 μC, and
• the charge amount difference ΔQ is calculated based on a mathematical expression (1)
• ΔQ=Q1−Q2 (1)
• where in mathematical expression (1), Q1 represents a charge amount of a non-exposed region of the surface of the photosensitive layer, Q2 represents a charge amount of an exposed region of the surface of the photosensitive layer, the exposed region is a region of the surface of the photosensitive layer charged to +600 V and then irradiated with exposure light having a wavelength of 780 nm and an exposure amount of 1.2 μJ/cm2, and the non-exposed region is a region of the surface of the photosensitive layer charged to +600 V and not irradiated with the exposure light thereafter