Study of the polarization photoluminescence of thick epitaxial GaN layers

Polarization photoluminescence spectra of gallium nitride were obtained. It follows from an analysis of the spectra that inhomogeneous broadening of the emission line having a half-width greater than 20 meV can be determined from the dispersion of the angles θ _c of the symmetry axes of the crystallites forming the epitaxial GaN layer, relative to the surface of the layer. Varying the angle of incidence, the focusing of the exciting laser beam, and the photoluminescence recording angle makes it possible to use polarization photoluminescence measurements for precision diagnostics of the quality of GaN layers. Fiz. Tekh. Poluprovodn. 33, 778–780 (July 1999)