An electrophotographic photosensitive member has a conductive substrate, a first layer structure with a single layer made mainly of amorphous silicon formed on the substrate, and a second layer structure including multiple layers also mainly made of amorphous silicon layered in succession on the first...http://www.google.se/patents/US4568622?utm_source=gb-gplus-sharePatent US4568622 - Electrophotographic photosensitive member and method for making such a member containing amorphous silicon
