Electronic and thermo‐physical properties of double antiperovskites X 6 SOA 2 (X = Na, K and A = Cl, Br, I): A non‐toxic and efficient energy storage materials

Abstract We have explored the structural, electronic and transport parameters of cubic double antiperovskite structure X 6 SOA 2 (X = Na, K and A = Cl, Br, I) using density functional theory followed by the solution of Boltzmann transport equation with constant relaxation time approximation. The exchange and correlation potential are described by the PBE‐GGA; the Becke‐Johnson approach modified by Tran and Blaha (TB‐mBJ) has been used to model the exchange‐correlation potential. Band gap of these materials have been found in between 2.85–4.24 eV. Thermoelectric properties have been computed at 300, 600 and 900 K. It has been found that figure of merit of double antiperovskite materials approaches to unity in both n‐ and p‐type regions. Hence these materials may turn out to be potential thermoelectric candidates. As these properties of the titled compounds have been explored for the very first time, hence, this work may open a new panorama for various detailed experimental and theoretical studies in the quest for non‐toxic, environmentally safe, and efficient energy sources.