Photoluminescence temperature behavior and Monte Carlo simulation of exciton hopping in InGaN multiple quantum wells

Application of Monte Carlo simulation of exciton (carrier) hopping for the analysis of the photoluminescence (PL) temperature behavior in In 0.2 Ga 0.8 N/GaN multiple quantum wells is reported. The PL linewidth and peak position measured in the 10–300 K range exhibited a W‐shaped and S‐shaped temperature behavior, respectively. The W‐shaped linewidth dependence was fitted with the results of Monte Carlo simulation, which involved phonon‐assisted exciton hopping through energy states confined in the band potential fluctuation minima. The simulation yielded the values of the standard deviation for potential fluctuations within In‐rich regions (31 meV), dispersion of the average exciton energy in different regions (29 meV), and the temperature dependence of the band gap, which was found to be in a fair agreement with the photoreflectance data. Our results, which infer in‐plane motion of localized excitons within the wells, are consistent with the model of large In‐rich regions (“segmented quantum wells” or “quantum discs”) with band potential fluctuations inside these regions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)