  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.
