Photoreceptor of a-Si:H with diodelike structure for electrophotography

Charging and photodischarging characteristics were investigated for the photoreceptors of amorphous silicon prepared by rf glow discharge of silane. For the positive corona, a sufficient charge retention was attained in the photoreceptor providing a thin layer of a-silicon doped with boron between the photosensitive Si:H film and the conductive substrate to prohibit the injection of carriers from the substrate. The photoconductivity gain of unity was attained in the photoreceptor when it was illuminated with visible light. A range-limited photocurrent flow was observed in the photoreceptor with a thick a-Si:H layer and the value of 2×10−8 cm2/V was estimated as μτ product of photoholes. The space-charge perturbed photocurrent was observed in the photoreceptor for the negative corona. The structure of the photoreceptor is intrinsic a-Si:H/n-type of a-silicon on a conductive substrate. In this case, the photocurrent flow was effectively perturbed by a space charge that accumulated in the photoconductor owing to the incomplete blocking.