Analysis of the temperature and excitation intensity dependencies of photoluminescence in undoped GaN films - art. no. 115205

Steady-state photoluminescence (PL) from undoped wurtzite GaN has been stud ied in detail over a wide range of temperatures and excitation intensities. Both the observed steps in the temperature dependence of the PL intensity, and the nonlinear dependence of the PL intensity on excitation power for d ifferent PL bands are quantitatively explained by competition between diffe rent recombination channels. Hole-Capture cross sections, defect concentrat ions, and thermal activation energies of the main acceptors in undoped GaN are estimated from the analysis of temperature and excitation intensity dep endencies of the PL.