azo compound no iv 1 a photosensitive member was prepared by forming a charge transport layer and further a charge generating layer in the same manner as in example iv 3 except that the same amount of tri p tolyl amine which is a triphenylamine compound was used as the charge transporting substance in lieu of abph a photosensitive member was prepared in the same manner as in example iv 7 except that the same amount of the azo compound no v 36 was used in lieu of the azo compound no iv 1 a photosensitive member was prepared by forming a charge transport layer and further a charge generating layer in the same manner as in example iv 3 except that the same amount of 2 5 bis p diethylaminophenyl 1 3 4 oxadiazole which is an oxadiazole compound was used as the charge transporting substance in lieu of abph a photosensitive member was prepared in the same manner as in example iv 9 except that the same amount of the azo compound no v 36 was used in lieu of the azo compound no iv 1 the thus obtained photosensitive members were measured for their electrophotographic characteristics using an electrostatic recording paper testing apparatus kawaguchi denki model sp 428 the results obtained are shown in table iv 1 the surface potential v s volts of each photosensitive member is the initial surface potential attained upon positively charging the photosensitive member surface by corona discharging at 6 0 kv in the dark for 10 seconds after allowing the member to stand in the dark for 2 seconds following discontinuation of the corona discharge the surface potential v d volts was measured the photosensitive member surface was then further irradiated with white light.