Texturing degree boosts thermoelectric performance of silver-doped polycrystalline snse

Abstract

Tin selenite (SnSe) has attracted significant attention due to its record thermoelectric figure of merit (ZT = 2.6 at 923 K) of its single crystal. However, the polycrystalline SnSe processes considerably less ZTs (⩽1.1). In this study, we investigate the thermoelectric properties of Ag-doped polycrystalline SnSe, which was synthesized via zone melting and hot pressing. By comparing our results and previous reports of Ag-doped single crystals and polycrystals, we determine that the high texturing degree is essential for achieving good thermoelectric performance in polycrystalline SnSe. The zone-melted Sn0.99Ag0.02Se shows better thermoelectric performance than the Ag-doped SnSe single crystal in the entire temperature range, exhibiting a peak ZT of 1.3 at 793 K.