The line-shapes and full-widths at half-height of the zero-phonon lines, and the relative photoluminescence intensities of defects with zero-phonon line energies of 2.463, 2.156 and 1.945eV, were studied in synthetic crystals with various morphologies. The line-shapes were related to the relative abundances of point and line defects. The defect intensities could also be related to the uptake of N, and to the formation of lattice defects during growth.

M.L.Fish, J.D.Comins: Materials Science Forum, 1997, 239-241, 103-6