Abstract
Rapid degradation of photoluminescence (PL) intensity under high excitation level (∼1 kW/cm2) was observed at fresh surfaces of GaAs crystals made by various growth methods. The Auger analyses showed quick oxide formation at the photoexcited GaAs surfaces. The degraded PL intensity was recovered by etchings only the oxide layers; thus, the cause of PL degradation was ascribed to the increase of nonradiative recombination at the oxide‐GaAs interface. The oxidation process was proved to be athermal. In contrast to GaAs, Al0.3Ga0.7As and InP showed no or slow degradations, respectively, under the same excitation condition.