An investigation was made of the effect of the growth temperature upon the point defect density of unintentionally doped samples which had been grown via ambient-pressure metalorganic chemical vapor deposition and hydride vapor-phase epitaxy. A correlation was found between photoluminescence spectra and the concentration 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. These native acceptors, which were probably Ga antisites, GaN, and/or Ga vacancies, VGa, were non-radiative defects. It was shown that a second donor level had an activation energy of about 0.0525eV, and produced a photoluminescence peak with an energy of about 3.45eV at low temperatures. Hall techniques showed that a third donor had an activation energy of 0.110eV.

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], 281-7