cw laser irradiation of GaAs: Arsenic formation and photoluminescence degradation

Abstract
Low-power, cw laser irradiation of GaAs leads to the formation of solid arsenic at the sample surface and to the degradation of band-gap photoluminescence (PL) efficiency. In situ Raman scattering and PL are used to measure the lattice and carrier temperature in addition to monitoring the arsenic formation and PL efficiency. Both effects are athermal, do not involve surface oxidation, and occur in n,p and semi-insulating GaAs prepared by different growth techniques. These observations suggest that arsenic formation and PL decrease may both be the result of a nonradiative recombination process.