Single-layer electrophotographic photosensitive member, process cartridge, and image forming apparatus

A single-layer electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer disposed directly on the conductive substrate, wherein

• the conductive substrate contains aluminum or an aluminum alloy,
• a surface of the conductive substrate has a film of an oxide of the aluminum or a film of an oxide of the aluminum alloy,
• the film of the oxide of the aluminum or the film of the oxide of the aluminum alloy has a thickness of at least 0.15 μm and no greater than 0.35 μm,
• the photosensitive layer contains a charge generating material and an electron transport material,
• the charge generating material is X-form metal-free phthalocyanine,
• the electron transport material has a reduction potential of at least −0.88 V and no greater than −0.66 V versus a reference electrode (Ag/Ag+),
• the single-layer electrophotographic photosensitive member has a leakage onset voltage of at least 5.0 kV in a high temperature and humidity environment at a temperature of 30° C. and a relative humidity of 80%, the leakage onset voltage being a voltage applied to the single-layer electrophotographic photosensitive member at which current leakage starts,
• the electron transport material includes a compound represented by general formula (2) or general formula (3) shown below,
• where in the general formulae (2) and (3),
• R3, R4, R5, R6, R7, and R8 each represent, independently of one another, an alkyl group that may have a substituent selected from the group consisting of alkoxy groups and halogen atoms or an aryl group that may have a substituent selected from the group consisting of alkoxy groups and halogen atoms, and
• a proportion R of oxygen atoms present in the film of an oxide of the aluminum or the film of an oxide of the aluminum alloy is at least 20% and no greater than 50%, the proportion R being calculated in accordance with equation (1) shown below,
• R=[AO/(AO+AAl)]×100 Equation (1)
• where in the equation (1),
• AO represents an oxygen atom concentration determined by measuring the film of an oxide of the aluminum or the film of an oxide of the aluminum alloy by energy dispersive X-ray spectroscopy, and
• AAl represents an aluminum atom concentration determined by measuring the film of an oxide of the aluminum or the film of an oxide of the aluminum alloy by energy dispersive X-ray spectroscopy.