Photoluminescence Spectroscopy of MBE Grown Gallium Antimonide

摘要

Experimental data are presented for the energy levels of the native acceptor andbound exciton emissions of GaSb grown by MBE and studied with low temperature photoluminescence (PL) spectroscopy. The undoped GaSb emissions showed a donor-acceptor pair transition with an observed emission peak at 776 meV, a peak at 716 meV usually associated with the ionization level of the acceptor, and bound exciton transitions in the energy range from 796 to 804 meV. Other unidentified peaks were observed at about 805 meV. Temperature and power dependence studies of the acceptor peak confirmed donor-acceptor pair (DAP) behavior. A GaSb sample grown with a high antimony background pressure had emissions which were broad as compared to those emissions of a sample grown with a lower V:III flux. The full width at half maximum was 45 meV and was due to multiple peaks. A temperature dependence study aided in the identification of three separation emissions, assigned as follows: 772 meV, due to a DAP, and 760 and 751 meV due to a deep acceptor level associated with a free to bound transition.