Compensation mechanism in semi-insulating GaAs: The role of intrinsic acceptor defects

Abstract
We present experimental evidence for the presence in semi-insulating undoped GaAs of the double-acceptor defect with ionization energies of 78 and 203 meV, which is currently attributed to the GaAs antisite in concentrations of at least 2×1015 cm−3. We then discuss the implications of this result for the compensation mechanism in these materials.