The transient capacitance method was used to analyze samples which had been grown by means of low-pressure organometallic vapor phase epitaxy, using triethylgallium or trimethylgallium as sources. Two deep levels, at 1.10 and 1.27eV, were observed in samples which had been prepared by using trimethylgallium, while a deep level at 0.80eV was observed in samples which had been prepared by using triethylgallium.

J.F.Chen, N.C.Chen, W.Y.Huang, W.I.Lee, M.S.Feng: Japanese Journal of Applied Physics, 1996, 35[2-7A], L810-2