Thermoelectric power factor of MnSb2X4 (X = S, Se) spinel chalcogenides – A DFT study

Abstract

Recently, spinel chalcogenides have been found to be promising class of materials in thermoelectric power generation. In this line, the complete understanding about electronic and thermoelectric properties of MnSb2S4 and MnSb2Se4 is crucial. With the help of first-principles calculations, its interesting characteristics are explored, including bonding nature, ground state magnetic ordering, mechanical stability, etc. A systematic study on these materials revealed their antiferromagnetic and semiconducting behaviour. The Seebeck coefficient as a function of carrier concentration has its maximum at 600 and 681 μV K−1 (T = 300 K) for hole doped MnSb2S4 and MnSb2Se4 respectively. Besides the coupled behaviour of Seebeck coefficient and electrical conductivity, an optimal power factor of 1.82 and 0.96 mW m−1 K−2 is attained at 300 K for MnSb2S4 and MnSb2Se4 respectively. This study suggests that both the spinels can be potential p-type thermoelectric materials for near room temperature power generation applications and enables the path for their experimental investigations.