Electrostatic photocopying machine

Claim 1

An electrostatic photocopying machine comprising: a printing member including a conductive substrate; a non-single-crystal p-type semiconductor layer formed on said conductive substrate; a non-single-crystal intrinsic semiconductor layer formed on said p-type semiconductor layer in order to induce a built-in electric field across the interface therebetween; an insulating layer formed on said intrinsic layer with an external surface to permit the passage of charge photo-generated in said intrinsic layer so that charge on the external surface can be neutralized; where the band gaps of the p-type layer and the intrinsic layer are substantially less than the bend gap of the insulating layer; and where said p-type layer, said instrinsic layer, and said insulating layer are selected from the group consisting of silicon, silicon with nitrogen, silicon with carbon and silicon with oxygen either in stoichiometric or non-stoichiometric amounts; means for providing said charge on said external surface of the insulating layer of the printing member; means for projecting a light image onto said external surface of said insulating layer to thus form an electrostatic charge image; and means for developing the electrostatic charge image to form a visible image pattern on the insulating layer of the printing member.