Enhanced thermoelectric figure of merit ($ZT$) of Te-doped FeSb$_2$ nanocomposite

FeSb2 is considered as a potential candidate for Peltier cooling applications because of its colossal value of Seebeck coefficient (45,000 $\mu$VK$^{-1}$) at around 10 K. Our earlier works [1,2] showed that the \textit{ZT} values of undoped FeSb$_2$ nanocomposites could not be improved significantly despite of the drastic reduction in thermal conductivity which we attributed to the suppression of phonon-drag effect due to increased scattering of phonons off the grain-boundaries in nanocomposites. In this work, we demonstrate that combining nanostructuring approach with Te-doping further improves the thermoelectric properties to yield an enhanced \textit{ZT} value in FeSb$_2$ nanocomposites.\\[4pt] [1] Huaizhou Zhao, Mani Pokharel, Gaohua Zhu, Shuo Chen, Kevin Lukas, Qing Jie, Cyril Opeil, Gang Chen, and Zhifeng Ren; \textit{Appl. Phys. Lett.} 99, 163101 \textbf{(2011)}\\[0pt] [2] Mani Pokharel, Huaizhou Zhao, Kevin Lukas, Zhifeng Ren, and Cyril Opeil; \textit{Mater. Res. Soc. Symp. Proc. Vol. 1, 2012 DOI:10.1557/opl.2012.150 456 5}