P-type electronic and thermal transport properties of Mg$_{2}$Sn$_{1-x}$Si$_{x}$
ORAL
Abstract
P-type Mg$_{2}$Sn doped with various acceptors$^{(1)}$$^{(2)}$ has been studied as a potential thermoelectric material. Because of its narrow band gap and high lattice thermal conductivity, the zT values of the binary compound are limited: zT$_{max}$ reported is 0.3$^{(3)}$. In this work, we synthesize and characterize p-type-doped Mg$_{2}$Sn$_{1-x}$Si$_{x}$ with various acceptors. Silicon is added in order to widen the band gap and scatter the phonons. The conduction band degeneracy that yields excellent zT in n-type material in the Mg$_{2}$Sn$_{1-x}$Si$_{x}$ alloy system unfortunately does not apply to p-type material. Thermomagnetic and galvanomagnetic properties (electrical resistivity, Seebeck, Hall, and Nernst coefficients) are measured, along with thermal conductivity and band gap measurements. Finally, zT values are reported. (1) H. Y. Chen et al. Journal of Electronic Materials, Vol. 38, No. 7, 2009 (2) S. Choi et al. Journal of Electronic Materials, Vol. 41, No. 6, 2012 (3) H. Y. Chen et al. Phys. Status Solidi A 207, No. 11, 2523-2531 (2010)
*The work is supported by the joint NSF/DOE program on thermoelectrics, NSF-CBET-1048622
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