OPTICAL AND ELECTRICAL PROPERTIES OF AMORPHOUS SEMICONDUCTOR DOPING SUPERLATTICES.

Doping modulated amorphous semiconductors have been made by silane plasma deposition in a two-chamber transfer system. The properties of a multilayer sample consisting of many 275 A thick n- and p- type layers are discussed. The photoconductivity is characterized by a normal short recombination process and one with a lifetime of days. The latter yields at 300 degree K a long-lived persistent excess conductivity (PPC) that anneals away near 450 degree K. The PPC might be due to the internal fields that separate electron-hole pairs and hinders recombination.