Bulk n-type Bi 2 Te 3 single crystals with optimized chemical composition were successfully prepared by a high temperature-gradient directional solidification method. We investigate the influence of alloy microstructure, chemical composition, and growth orientation on the thermoelectric transport properties. The results show that the composition of single-crystal Bi 2 Te 3 alloy, along the c axis direction, could be slightly tuned by changing the growth rate of the crystal. At a rate of 18 mm/h, the formed Bi 2 Te 3 crystal exhibits good thermoelectric properties. At 300 K, a maximum Seebeck coefficient of −245 µV/K and an electrical conductivity of 5.6 × 10 4 S/m are acquired. The optimal power factor is obtained as 3.3 × 10 −3 W/K 2 m, with a figure of merit of 0.74. It can be attributed to the increased tellurium allocation in the Bi 2 Te 3 alloys, as verified well by the density functional theory calculations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.