Native defects in the AlxGa1−xSb alloy semiconductor

Defect concentrations in AlxGa1−xSb which is in equilibrium with a liquid phase are calculated. When the liquid phase is Ga rich, a Ga antisite (Ga2−Sb) or an Al antisite (Al2−Sb) is dominant, and the concentrations of vacancies are much smaller than the antisite concentrations. Ga2−Sb is dominant in GaSb equilibrated with a Sb‐rich solution, but the concentration of Sb antisites comes close to that of Ga2−Sb as temperature is lowered. For x larger than 0.6, a group‐III vacancy is the predominant defect in the case of Sb‐rich solutions. Calculated net acceptor concentrations agree well with those determined experimentally. A complex defect composed of GaSb and a Ga vacancy, which have been taken as the dominant residual acceptor, is expected to be negligible.