Photoquenching and thermal recovery of a thermally stimulated current peak in semi-insulating GaAs

Abstract

A prominent thermally stimulated current peak T5 appearing in semi-insulating GaAs is shown to photoquench under infrared illumination, and then thermally recover at a rate r=2.0×108 exp(-0.26 eV/kT) s-1, exactly the same as that observed for EL2, within experimental error. Two possible explanations exist: (1) T5 and EL2 are microscopically very similar, probably each with an AsGa core; or (2) T5 is an electron trap that only appears to quench and recover with EL2 because EL2 controls the electron lifetime. Several other traps show similar quenching and recovery behavior.