Probing exciton localization in non-polar GaN/AlN Quantum Dots by single   dot optical spectroscopy
  We present an optical spectroscopy study of non-polar GaN/AlN quantum dots by time-resolved photoluminescence and by microphotoluminescence. Isolated quantum dots exhibit sharp emission lines, with linewidths in the 0.5-2 meV range due to spectral diffusion. Such linewidths are narrow enough to probe the inelastic coupling of acoustic phonons to confined carriers as a function of temperature. This study indicates that the carriers are laterally localized on a scale that is much smaller than the quantum dot size. This conclusion is further confirmed by the analysis of the decay time of the luminescence. 
F. Rol, S. Founta, H. Mariette, B. Daudin, Le Si Dang, J. Bleuse, D.   Peyrade, J.-M. Gerard and B. Gayral