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 t he emission line having a half-width greater than 20 meV can be determined from the dispersion of the angles theta(c) of the symmetry axes of the crys tallites forming the epitaxial GaN layer, relative to the surface of the la yer. Varying the angle of incidence, the focusing of the exciting laser bea m, and the photoluminescence recording angle makes it possible to use polar ization photoluminescence measurements for precision diagnostics of the qua lity of GaN layers. (C) 1999 American Institute of Physics. [S1063-7826(99) 00407-X].