Recombination processes with and without momentum conservation in degenerate InN

We report on a theoretical approach in which the two cases of recombination with and without momentum conservation in optically excited high carrier concentration InN are considered. The calculations are used to analyze emission spectra of n-type InN layers of electron concentrations from 7.7 x 10 17 to 1.4 × 10 19 cm -3 studied in the temperature range between 9 and 100 K. The spectra peak near 0.7 eV and the applicability of the two approaches with increasing carrier concentration is estimated. Different transition mechanisms are considered in order to properly account for the observed features in the spectra. Recombination processes involving acceptor- and donor-like localized states are discussed.