Abstract: An improved electrophotographic photoreceptor includes a blocking layer formed from a doped, microcrystalline semiconductor alloy. The blocking layer is adapted to cooperate with the photoconductive layer of the photoreceptor to prevent the injection of undesirable charge carriers into the bulk of the photoconductive layer. Also disclosed are methods for the fabrication of the improved photoreceptor.

Abstract: An apparatus and process utilizes microwave energy for depositing amorphous alloy materials in layered form onto a receiving surface. The process results in materials having unique properties suitable for many applications including photovoltaic applications. The process includes the steps of providing at least one source of microwave energy, providing at least two reaction gases, each gas containing at least one alloying element to be deposited onto the receiving surface, and selectively exciting the reaction gases with microwave energy to create excited species containing the alloying elements to be deposited for depositing the alloys in alternating layers onto the receiving surface. For depositing alternating layers of silicon and germanium alloys, the reactions gases can include silane (SiH.sub.4) or silicon tetrafluoride (SiF.sub.4), and germane (GeH.sub.4) or germanium tetrafluoride (GeF.sub.4).

Abstract: A process for making amorphous semiconductor alloy films and devices at high deposition rates utilizes microwave energy to form a deposition plasma. The alloys exhibit high quality electronic properties suitable for many applications including photovoltaic applications.The process includes the steps of providing a source of microwave energy, coupling the microwave energy into a substantially enclosed reaction vessel containing the substrate onto which the amorphous semiconductor film is to be deposited, and introducing into the vessel reaction gases including at least one semiconductor containing compound. The microwave energy and the reaction gases form a glow discharge plasma within the vessel to deposit an amorphous semiconductor film from the reaction gases onto the substrate. The reactions gases can include silane (SiH.sub.4), silicon tetrafluoride (SiF.sub.4), silane and silicon tetrafluoride, silane and germane (GeH.sub.4), and silicon tetrafluoride and germane.

Abstract: A low pressure process for making amorphous semiconductor alloy films and devices at high deposition rates and high gas conversion efficiencies utilizes microwave energy to form a deposition plasma. The alloys exhibit high-quality electronic properties suitable for many applications including photovoltaic and electrophotographic applications.The process includes the steps of providing a source of microwave energy, coupling the microwave energy into a substantially enclosed reaction vessel containing the substrate onto which the amorphous semiconductor film is to be deposited, introducing into the vessel at least one reaction gas and evacuating the vessel to a low enough deposition pressure to deposit the film at high deposition rates with high reaction gas conversion efficiencies without any significant powder or polymeric inclusions. The microwave energy and the reaction gases form a glow discharge plasma within the vessel to deposit an amorphous semiconductor film from the reaction gases onto the substrate.

Abstract: The formation of a body of material on a substrate having at least two layers of different composition is made possible by the improved system and method of the present invention with minimized cross contamination between the respective deposition environments in which the layers are deposited. The disclosure relates more specifically to the use of the system and method for the deposition of multi-layered amorphous silicon alloys to form photovoltaic devices. As a preferred embodiment of the invention, first, second, and third glow discharge deposition chambers are provided for depositing respective first, second, and third amorphous silicon alloy layers on a substrate. The second layer is substantially intrinsic in conductivity and differs in composition from the first and third layers which are of opposite conductivity type by the absence of at least one element.