Point defects introduced by InN alloying into In x Ga1− x N probed using a monoenergetic positron beam

• Published in: Journal of applied physics 2013-03, Vol.113 (12)
• Main Authors: Uedono, A., Tsutsui, T., Watanabe, T., Kimura, S., Zhang, Y., Lozac'h, M., Sang, L. W., Ishibashi, S., Sumiya, M.
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4795815

Native defects in InxGa1−xN (x = 0.06-0.14) grown by metal organic chemical vapor deposition were studied using a monoenergetic positron beam. Measurements of Doppler broadening spectra of the annihilation radiation as a function of incident positron energy for InxGa1−xN showed that vacancy-type defects were introduced with increasing InN composition, and the major defect species was identified as complexes between a cation vacancy and a nitrogen vacancy. The concentration of the divacancy, however, was found to be suppressed by Mg doping. The momentum distribution of electrons at the InxGa1−xN/GaN interface was close to that in defect-free GaN or InxGa1−xN, which was attributed to localization of positrons at the interface due to the built-in electric field, and to suppression of positron trapping by vacancy-type defects. We have also shown that the diffusion property of positrons is sensitive to an electric field near the InxGa1−xN/GaN interface.