Resonant excitation photoluminescence studies of InGaN/GaN single quantum well structures

The optical properties of InGaN/GaN quantum well structures, with indium fractions of 0.15 and 0.25, have been studied under resonant excitation conditions. The low-temperature (T=6 K) photoluminescence spectra revealed a broad recombination peak that the authors have attributed to the acoustic-phonon assisted emission from a distribution of localized states, excited via an acoustic-phonon assisted absorption process. Comparing these results with theoretical calculations, where the authors consider the deformation potential coupling of the separately localized electron/hole pairs to an effectively continuous distribution of acoustic phonons, gives a value of approximately 2.5 A for the in-plane localization length scale. (c) 2006 American Institute of Physics.