The density of dislocations in n-type GaN was measured by photo-electrochemical etching. A 10x reduction in dislocation density was observed compared to planar GaN grown at the same time. Cross-sectional transmission electron microscopy studies indicated that defect reduction was due to the mutual cancellation of dislocations with equal and opposite Burger’s vectors. The nanoheteroepitaxy sample exhibited significantly higher photoluminescence intensity and higher electron mobility than the planar reference sample.

Photo-Electrochemical Etching Measurement of Defect Density in GaN Grown by Nanoheteroepitaxy. M.S.Ferdous, X.Y.Sun, X.Wang, M.N.Fairchild, S.D.Hersee: Journal of Applied Physics, 2006, 99[9], 096105 (3pp)