Crystalline photoconductive films for electrophotographic recording

Crystalline photoconductive films of mixed crystal materials Cd sub 1-y Zn sub x S and CdS sub 1-y Se sub y were developed for electrophotographic plates with high charging voltages. Film growth is performed by sputter deposition, which allows growing of homogeneous films with low dark decay combined with high photoelectric gain and nearly vanishing residual potential. Panchromatic sensitivity is achieved for the largest part of the visible range, depending on the choice of material composition. An increase in the number of copies per drum is expected due to the high thermal and mechanical stability of the material. Remarkable enhancement of spatial resolution of the copies is expected due to the high charging voltages at reduced film thickness.