PHOTOSTRUCTURAL DEFECT STATES AND RESIDUAL POTENTIAL IN CHLORINE AND ARSENIC DOPED AMORPHOUS SELENIUM FILMS

The mechanism of photostructural defect states and buildup of residual potential in pure, chlorine doped, and combinationally doped, i.e., chlorine and arsenic doped amorphous selenium films (approximately 100 mum) has been studied using the thermally stimulated discharge current technique. Combinationally doped films show minimum buildup of residual potential even though the photostructural defect states in them lie between the pure and the chlorine doped amorphous selenium films. These results have been explained in terms of the conductivity enhancement role of chlorine and the complimentary role of arsenic in sustaining the acceptance potential in the doped films.