Enhanced thermoelectric properties of n-type direction solidified Bi2Te2.7Se0.3 alloys by manipulating its liquid state

Liquid state manipulation (LSM) has been applied to prepare direction solidified Bi2Te2.7Se0.3 bulk alloys. The maintained strong texturing and increased effective mass benefits the power factor. Moreover, the lattice thermal conductivity in Bi2Te2.7Se0.3 reduces to 0.55 Wm(-1) K-1 at 4901(after LSM. As a result, the largest ZT value of 1.10 is achieved for the sample experienced LSM, which is increased by 20% compared with that unexperienced ISM. The average ZTvalue for LSM sample rises from 0.80 to 1.02, which makes this material suitable for application in the wide temperature range. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.