Plan-view transmission electron microscopic and cathodoluminescence images were obtained from exactly the same location in a specimen of n-type material which had been grown on a sapphire substrate by using metalorganic chemical vapor deposition. There was found to be a clear one-to-one correspondence between the dark spots which were observed in cathodoluminescence images, and the dislocations in transmission electron microscopy foils; thus indicating that the dislocations were non-radiative recombination centers. The efficiency of light emission was high provided that the minority carrier diffusion length was shorter than the dislocation spacing.

Direct evidence that dislocations were non-radiative recombination centers in GaN T.Sugahara, H.Sato, M.Hao, Y.Naoi, S.Kurai, S.Tottori, K.Yamashita, K.Nishino, L.T.Romano, S.Sakai: Japanese Journal of Applied Physics - 2, 1998, 37[4A], L398-400