Photosensitive elements for electrophotographic applications

摘要

The present invention relates to a photosensitive element of the Se-based function separation type for use in an electrophotographic instrument in which long-wave light is used for writing. The photosensitive element is distinguished by excellent abrasion resistance and heat resistance at the same time as good electrical properties. This is achieved by arranging an interlayer of an As/Se alloy between the surface protection layer and the chargeable layer. The interlayer contains As in a concentration which increases over the layer thickness from the chargeable layer to the surface protection layer. This As concentration gradient causes the thermal coefficient of expansion to drop gradually over the layer thickness from the chargeable layer to the surface protection layer. The interlayer therefore protects the surface protection layer against thermal stress and fractures which could occur since the surface protection layer has a coefficient thermal expansion which is lower than that of the selenium alloy.