Photoquenching phenomenon enhanced by proton irradiation in semi-insulating GaAs

Abstract
In undoped semi‐insulating GaAs, we have found that the quenching phenomena of photoconductance and infrared absorption are enhanced by proton irradiation above 1013 /cm2, accompanied by an increase in near‐band‐edge infrared absorption. These phenomena disappear with the annihilation of the proton‐induced near‐band absorption by annealing at 350 °C. It is suggested that the enhanced photoquenching phenomena arise from the increase in the quenchable component due to the transition from the ionized midgap electron trap (EL2+) to the neutral EL20.