P-type conductivity in GaN:Be epitaxial layers
Abstract
Electron transport properties of Be-doped heteroepitaxial GaN layers grown by metalorganic vapor phase epitaxy were investigated by means of temperature-dependent Hall effect measurements. The Be concentration was in the range of 4 × 1018−3 × 1019 cm−3. P-type conductivity (not overcompensated by Be-related donors) from the isolated substitutional BeGa acceptors was revealed in all studied samples, with the highest room-temperature hole concentration of 4 × 1013 cm−3 for the most conductive sample. Resistivity of 10 kΩ cm and mobility of about 15 cm2/Vs were achieved. The conductivity decreased with increasing Be concentration, strongly indicating a self-compensation mechanism. Quantitative analysis of temperature-dependent Hall effect data showed a relatively deep position of the BeGa acceptor level, at EV + 0.40 eV. This finding is consistent with the deep polaronic state of the Be acceptor revealed in previous optical and theoretical studies.
Article Details
Journal Info
Journal of Applied Physics
American Institute of Physics
Authors (4)
M. Zając
M. A. Reshchikov
Department of Physics, Virginia Commonwealth University 1 , Richmond, Virginia 23220,
B. McEwen
Department of Nanoscale Science and Engineering, State University of New York-Albany 1 , Albany, New York 12203,
F. Shahendipour-Sandvik
Department of Nanoscale Science and Engineering, SUNY-Albany 3 , Albany, New York 12222,