Increased p-type conductivity in GaN{sub x}Sb{sub 1−x}, experimental and theoretical aspects

Journal Article · Fri Aug 28 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4929751· OSTI ID:22494814

Makkonen, I.; Slotte, J.; Kujala, J.; Tuomisto, F. ^[1]; Veal, T. D. ^[2]; Ashwin, M. J. ^[3]

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1. Department of Applied Physics, Aalto University, P.O. Box 14100, FIN-00076 Aalto Espoo (Finland)
2. Department of Physics and Stephenson Institute for Renewable Energy, University of Liverpool, Liverpool L69 7ZF (United Kingdom)
3. Department of Chemistry, University of Warwick, Coventry CV4 7AL (United Kingdom)

The large increase in the p-type conductivity observed when nitrogen is added to GaSb has been studied using positron annihilation spectroscopy and ab initio calculations. Doppler broadening measurements have been conducted on samples of GaN{sub x}Sb{sub 1−x} layers grown by molecular beam epitaxy, and the results have been compared with calculated first-principle results corresponding to different defect structures. From the calculated data, binding energies for nitrogen-related defects have also been estimated. Based on the results, the increase in residual hole concentration is explained by an increase in the fraction of negative acceptor-type defects in the material. As the band gap decreases with increasing N concentration, the ionization levels of the defects move closer to the valence band. Ga vacancy-type defects are found to act as positron trapping defects in the material, and the ratio of Ga vacancy-type defects to Ga antisites is found to be higher than that of the p-type bulk GaSb substrate. Beside Ga vacancies, the calculated results imply that complexes of a Ga vacancy and nitrogen could be present in the material.

• OSTI ID: 22494814
• Journal Information: Journal of Applied Physics, Vol. 118, Issue 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANNIHILATION
BINDING ENERGY
COMPARATIVE EVALUATIONS
CONCENTRATION RATIO
DEFECTS
DOPPLER BROADENING
EXPERIMENT RESULTS
GALLIUM ANTIMONIDES
GALLIUM NITRIDES
HOLES
MOLECULAR BEAM EPITAXY
NITROGEN
POSITRONS
P-TYPE CONDUCTORS
SPECTROSCOPY
VALENCE