Chemical modification of the electrical behavior of a-Se and its alloys-xerographic studies

The extent to which the photoelectronic properties of amorphous chalcogenides can be varied by chemical modification remains a key issue in the study of this technologically important class of semiconductors. a-Se is a prototypical system whose elemental nature and ambipolarity make it particularly attractive for such a study. In the following, the effect of the equilibrium doping of a-Se with halogens and alkalis will be summarized. Doping effects on thermal generation and deep trapping have been examined using xerographic techniques. The effect of dopants on magnetic properties has been measured by electron spin resonance (esr). The experimental results are compared to predictions of recently proposed defect models.