An antimony-related electronic level in isovalently doped bulk GaAs

Abstract
Temperature-dependent Hall-effect and photoluminescence measurements have been performed on a series of antimony-doped bulk GaAs samples that were otherwise undoped. A new donor level located 0.48 eV below the conduction-band edge has been detected by both experiments in all antimony-doped samples studied. This level reduces the resistivity of antimony-doped material below the semi-insulating limit. Comparison with known intrinsic levels in undoped material have been made and it is shown that the 0.48-eV donor is distinct from any of these. It is concluded that the defect responsible for the 0.48-eV donor involves an impurity antisite SbGa either isolated or in a complex with intrinsic defects.