Origin of the 0.82-eV electron trap in GaAs and its annihilation by shallow donors

Abstract

The concentration of the major electron trap (0.82 eV below the conduction band) in GaAs (Bridgman grown) was found to increase with increasing As pressure during growth. It was further found that (for a given As pressure) the concentration of this trap decreased with increasing concentration of shallow donor dopants (Si, Se, and Te). Donor concentrations above a threshold of about 1017 cm−3 led to the rapid elimination of the trap. On the basis of these findings, the 0.82-eV trap was attributed to the antisite defect AsGa formed during the postgrowth cooling of the crystals.