  Photoluminescence spectra from disordered InN were studied in very high
magnetic fields. The samples had Gaussian spectra with low temperature emission
peaks at 0.82 and 0.98eV respectively. The average spatial extent of the
excitonic wave functions, inferred from the diamagnetic shift, is only 2-3nm.
This shows that the recombination is from an ensemble of highly localized
states within a landscape of a smooth (classical) disorder potential of
strength of the order of 10meV. The anomalies in the temperature dependence of
the photoluminescence peak and linewidth give further support to the picture of
trapped photoexcited carriers.
