Photoluminescence and interfacial heat transfer in gallium arsenide

Abstract

Laser heating of irradiated samples will occur whenever the sample does not make thermal contact to a heat sink. We have explored laser heating of GaAs samples under modest excitation powers by observing photoluminescence intensity versus time. The observed photoluminescence diminishes exponentially in time following illumination, and the initial photoluminescence intensity is recovered after illumination ceases with the same time constant as observed in the degradation. A model based on linear interfacial heat transfer predicts exponential photoluminescence degradation, and the effect is parameterized in terms of an interfacial heat transfer constant. A variety of experimental results are consistent with predictions of the model.