An investigation was made of the effect of growth temperature upon the point defect density in non-intentionally doped material which had been grown by means of atmospheric-pressure metalorganic chemical vapour deposition and hydride vapour-phase epitaxy. A correlation was found between the photoluminescence spectra and the concentrations of donors and acceptors. It was shown that O created a shallow donor, with an activation energy of about 0.0235eV. It was found that the concentration of native acceptors increased with increasing growth temperature. The native acceptors, which were thought to be Ga antisites and/or Ga vacancies, were non-radiative defects. A second donor level had an associated activation energy of about 0.0525eV, and produced a photoluminescence peak with an energy of about 3.45eV at low temperatures. Hall effect data showed that a third donor had an activation energy of 0.11eV.

Effect of Growth Temperature on Point Defect Density of Unintentionally Doped GaN Grown by Metalorganic Chemical Vapor Deposition and Hydride Vapor-Phase Epitaxy V.A.Joshkin, C.A.Parker, S.M.Bedair, J.F.Muth, I.K.Shmagin, R.M.Kolbas, E.L.Piner, R.J.Molnar: Journal of Applied Physics, 1999, 86[1], 281-8