Temperature and excitation power dependence of photoluminescence from high quality GaSb grown on AlSb and GaSb buffer layers

Abstract

High quality GaSb layers were grown on semi-insulating (001) GaAs substrates by molecular-beam epitaxy, using AlSb and GaSb buffer layers. We observed strong photoluminescence even for temperatures higher than 100 K. The photoluminescence intensity was significantly increased when AlSb/GaSb superlattices were grown on the GaSb layer. With increasing the excitation power, the ratio of the acceptor-bound exciton with respect to the donor-acceptor pair transition is increased due to the saturation of the donor-acceptor pair transitions. We also observed an abnormal increase in the intensity with increasing temperatures up to 100 K. This unusual behavior is attributed to the influence of deep centers.