Potential Thermoelectric Performance from Optimization of Hole-Doped Bi2Se3

We present an analysis of the potential thermoelectric performance of hole-doped Bi2Se3, which is commonly considered to show inferior room temperature performance when compared to Bi2Te3. We find that if the lattice thermal conductivity can be reduced by nanostructuring techniques (as have been applied to Bi2Te3 in Refs. [W. Xie, X. Tang, Y. Yan, Q. Zhang, and T. M. Tritt, Unique Nanostructures and Enhanced Thermoelectric Performance of Melt-Spun BiSbTe Alloys, Appl. Phys. Lett. 94, 102111 (2009); B. Poudel et al., High-Thermoelectric Performance of Nanostructured Bismuth Antimony Telluride Bulk Alloys, Science 320, 634 (2008).]) the material may show optimized ZT values of unity or more in the 300-500 K temperature range and thus be suitable for cooling and moderate temperature waste heat recovery and thermoelectric solar cell applications. Central to this conclusion are the larger band gap and the relatively heavier valence bands of Bi2Se3.