Photoluminescence and cathodoluminescence spectra were studied in epitaxial GaN which had been laterally overgrown onto (00•1) sapphire. Photon recycling, which affected the position of the near-bandedge transition, was seen in cathodoluminescence spectra upon changing the accelerating voltage. Cathodoluminescence monochromatic images, which were recorded at various wavelengths, showed that dislocations acted as efficient non-radiative recombination centres and were not responsible for the yellow band.

Luminescence of Epitaxial GaN Laterally Overgrown on (00•1) Sapphire Substrate - Spectroscopic Characterization and Dislocation Contrast. S.Dassonneville, A.Amokrane, B.Sieber, J.L.Farvacque, B.Beaumont, P.Gibart: Journal of Applied Physics, 2001, 89[7], 3736-43