Abstract
Hall effect, photoluminescence, and photoconductivity measurements on residual acceptors in GaSb grown by the Bridgman method, are presented and discussed with emphasis on the determination of energy level positions. The effect of thermal annealing or Li-diffusion on the behavior of the energy levels of residual acceptors is investigated to ascertain the nature of doubly-ionizable acceptors. Photoluminescence data on the Au-GaSb Schottky barrier give additional results confirming that the rediual acceptor is doubly ionizable. Direct evidence for the defect configuration is also presented.