Temperature dependent optical properties of InGaN/GaN quantum well structures

We have investigated the variation of the photoluminescence intensity and decay time as a function of temperature of a series of InGaN/GaN quantum well structures in which the number of quantum wells was varied. All the samples exhibited a decrease in photoluminescence intensity and decay time with increasing temperature with the rate of decrease being reduced as the number of quantum wells was increased. We have compared these results with a theoretical model which describes the effects of thermally excited carrier escape and recapture. We find reasonable agreement with the results of the model and the experiments for the samples incorporating only a few quantum wells supporting the idea that thermally excited carrier loss is the main non-radiative recombination path.