Vacancy-type defects in In{sub x}Ga{sub 1-x}N alloys probed using a monoenergetic positron beam

Journal Article · Sun Jul 01 04:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4732141· OSTI ID:22089306

Uedono, A.; Watanabe, T. ^[1]; Ishibashi, S. ^[2]; Wang, X. Q.; Liu, S. T.; Chen, G.; Shen, B. ^[3]; Sang, L. W.; Sumiya, M. ^[4]

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1. Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)
2. Nanosystem Research Institute (NRI) 'RICS,' National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan)
3. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)
4. Wide Bandgap Material Group, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan)

Native defects in In{sub x}Ga{sub 1-x}N grown by plasma-assisted molecular beam epitaxy were probed by a monoenergetic positron beam. Doppler broadening spectra of the annihilation radiation were measured, and these were compared with results obtained using first-principles calculation. The defect concentration increased with increasing In composition x and reached the maximum at x = 0.44{approx}0.56. A clear correlation between the line-width of photoluminescence and the defect concentration was obtained. The major defect species detected by positron annihilation was identified as cation vacancies coupled with multiple nitrogen vacancies (V{sub N}s), and their introduction mechanism is discussed in terms of the strain energy due to bond-length/angle distortions and the suppression of the V{sub N} formation energy by neighboring In atoms.

• OSTI ID: 22089306
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 1 Vol. 112; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNIHILATION
ATOMS
CORRELATIONS
DOPPLER BROADENING
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
LAYERS
LINE WIDTHS
MOLECULAR BEAM EPITAXY
NITROGEN COMPOUNDS
PHOTOLUMINESCENCE
POINT DEFECTS
POSITRON BEAMS
SEMICONDUCTOR MATERIALS
SPECTRA
TERNARY ALLOY SYSTEMS
VACANCIES