Laser-induced degradation of GaAs photoluminescence

We report experimental studies of laser-induced degradation of surface photoluminescence efficiency in n-GaAs, p-GaAs, semi-insulating Cr-doped, and undoped liquid-encapsulated Czochralski-grown GaAs for excitation intensities ranging from ∼0.1 to ∼20 kW/cm2. The data suggest a contribution from optically induced defects in the bulk material. The time dependence of photoluminescence efficiency was fitted to a simple power-law expression. A previously unreported fast decay of photoluminescence, occurring in 1–2 s immediately following the cleaving of a fresh surface, was observed in p- and n-type samples.