Fabrication of InSb crystal via Horizontal Bridgman method and investigation on its thermoelectric properties

Abstract

In this work, an undoped Ⅲ-Ⅴ group InSb crystal was prepared through a Horizontal Bridgman method. The as-grown crystal has standard F43 m phase structure and precise stoichiometric ratio at room temperature. Its electrical and thermal transport properties along (110) cleavage plane has been investigated. The electrical conductivity σ is increased from 1224.6 Scm−1 to 2282 Scm−1 in the temperature range of 300−700 K. The Seebeck coefficient S is always negative, which means this crystal is a n type semiconductor, and the largest S is −180.2 μVK-1 near 700 K. As for the total thermal conductivity ktot, the lowest value of 8.2 Wm-1 K-1 is achieved under the same temperature. Ultimately, a maximum figure of merit ZT = 0.63 is obtained around 700 K which reveals InSb crystal might be a promising middle- temperature thermoelectric (TE) material for energy conversion application in the future.