Carrier compensation and scattering mechanisms in p-GaSb

Dutta, PS and Prasad, V and Bhat, HL and Kumar, Vikram (1996) Carrier compensation and scattering mechanisms in p-GaSb. In: Journal of Applied Physics, 80 (5). pp. 2847-2853.

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Abstract

The hole transport properties of gallium antimonide with various degrees of tellurium compensation have been investigated in the temperature range of 4.2–300 K. For the undoped GaSb, the p-type conductivity arises from a doubly ionizable native defect $V_{Ga}Ga_{Sb}$.In the Te compensated samples, apart from the Te-donor level and the $V_{Ga}Ga_{Sb}$ center, an acceptor level resulting from complexation of $V_{Ga}Ga_{Sb}$ with $Te_{Sb}$ has been found. This acceptor level lies \sim70 meV above the valence band edge. The concentration of this center depends on the melt composition and the level of Te present in the melt during growth of crystals. Most interestingly, at very low level of Te concentration, an additional triple native acceptor $(V_{Ga} Ga_{Sb} V_{Ga})$ has also been observed. With the increase in Te concentration, the mobility decreases and a shift in the mobility peak to higher temperature is observed. The low-temperature mobility is limited by ionized impurity scattering. At higher temperatures, the scattering mechanisms depend on Te concentration in the sample. In this regime, significant contributions from acoustic, nonpolar optical, and polar optical phonon scattering are observed for samples with low levels of Te. In contrast, the impurity scattering dominates even at room temperature for highly compensated crystals.

Item Type:	Journal Article
Publication:	Journal of Applied Physics
Publisher:	American Institute of Physics
Additional Information:	Copyright of this article belongs to American Institute of Physics.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	12 Dec 2006
Last Modified:	19 Sep 2010 04:33
URI:	http://eprints.iisc.ac.in/id/eprint/9076

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