The defect evolution and its correlation with electrical properties of GaN films grown by metalorganic chemical vapour deposition were investigated. It was found that the dislocation density decreased gradually during the growth process, and the dislocation reduction rate in the island coalescence process was especially rapid. The changes in electron mobility of GaN with the increase of growth time were mainly dependent on the dislocations acting as scattering centers. Furthermore, the variation of carrier concentration in GaN may be related with the point defects and their clusters. The quality of GaN could be improved by suitably increasing the film thickness.

Defect Evolution and Accompanied Change of Electrical Properties during the GaN Growth by Metalorganic Chemical Vapor Deposition. D.G.Zhao, D.S.Jiang, J.J.Zhu, X.Guo, Z.S.Liu, S.M.Zhang, Y.T.Wang, H.Yang: Journal of Alloys and Compounds, 2009, 487[1-2], 400-3