Assessment of the thermoelectric performance of polycrystalline p-type SnSe

We report the evaluation of the thermoelectric performance of polycrystalline p-type SnSe, a material in which unprecedented values of the thermoelectric figure of merit ZT have been recently discovered in single crystals. Besides anisotropic transport properties, our results confirm that this compound exhibits intrinsically very low thermal conductivity values. The electrical properties show trends typical of lightly doped, intrinsic semiconductors with thermopower values reaching 500 mu V K-1 in a broad temperature range. An orthorhombic-to-orthorhombic transition sets in at 823 K, a temperature at which the power factor reaches its maximum value. A maximum ZT of 0.5 was obtained at 823 K, suggesting that proper optimization of the transport properties of SnSe might lead to higher ZT values. These findings indicate that this system represents an interesting experimental platform for the search of highly efficient thermoelectric materials. (C) 2014 AIP Publishing LLC.