Influence of laser annealing on defect-related luminescence of InGaN epilayers

InGaN epilayers exhibiting strong defect-related sub-bandgap emission, which is undesirable in epilayers and quantum well structures designed for light-emitting diodes and laser diodes, have been studied by confocal photoluminescence spectroscopy, Auger electron spectroscopy, and atomic force microscopy. Inhomogeneous spatial distribution of band-edge luminescence intensity and comparatively homogenous distribution of defect-related emission are demonstrated. It is shown that laser annealing at power densities causing the increase of the temperature at the epilayer surface high enough for indium atoms to move to the surface results in suppression of the defect-related emission.