Nonpolar a-plane and m-plane GaN layers grown by metal organic chemical vapour deposition employing sidewall epitaxial lateral overgrowth were studied by photoluminescence  and spatially resolved micro-photoluminescence. The effects of the groove orientations and the groove/terrace width ratio on the emission spectra, particularly on the stacking fault  related emission bands in the 3.29-3.42eV spectral region, were examined. The photoluminescence spectra of both types of non-polar layers reveal a significant reduction of the defect related emissions when the grooves were oriented perpendicular to the c-axis of GaN and the groove/terrace width ratio was smaller than one. The suppression of stacking fault formation in the areas where a lateral overgrowth along the [00•1] GaN direction occurred was confirmed by micro-photoluminescence measurements showing no stacking fault related emissions over the terrace regions.

Nonpolar GaN Layers Grown by Sidewall Epitaxial Lateral Overgrowth: Optical Evidences for a Reduced Stacking Fault Density. P.P.Paskov, B.Monemar, D.Iida, T.Kawashima, M.Iwaya, S.Kamiyama, H.Amano, I.Akasaki: Physica Status Solidi C, 2008, 5[6], 1768-70