Ga vacancies as dominant intrinsic acceptors in GaN grown by hydride vapor phase epitaxy

• Published in: Applied physics letters Vol. 82; no. 20; pp. 3433 - 3435
• Main Authors: Oila, J., Kivioja, J., Ranki, V., Saarinen, K., Look, D. C., Molnar, R. J., Park, S. S., Lee, S. K., Han, J. Y.
• Format: Journal Article
• Language: English
• Published: 19-05-2003
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.1569414

Positron annihilation measurements show that negative Ga vacancies are the dominant acceptors in n-type gallium nitride grown by hydride vapor phase epitaxy. The concentration of Ga vacancies decreases, from more than 1019 to below 1016 cm−3, as the distance from the interface region increases from 1 to 300 μm. These concentrations are the same as the total acceptor densities determined in Hall experiments. The depth profile of O is similar to that of VGa, suggesting that the Ga vacancies are complexed with the oxygen impurities.