Lead-free indium-silver based double perovskites for thermoelectric applications: Structural, electronic and thermoelectric properties using first-principles approach

Energy consumption is increasing day by day in today's world so it is the matter of concern for the scientific community to find the alternative power generation mechanisms by minimizing the whole world's reliance on traditional power generation methods. Thermoelectricity has emerged as an attractive area of research for finding an efficient non-traditional power generation mechanism. In this scenario, it is a matter of immense potential to find more efficient materials for thermoelectric power generation and refrigeration. In this work, the structural, electronic and thermoelectric properties of double perovskites X2InAgCl6 (X=Cs,K,Rb) have been studied in details using density functional theory (DFT) within the frame work of generalized gradient approximation(GGA). The results of Cs2InAgCl6 are consistent with already reported data whereas K2InAgCl6 and Rb2InAgCl6 have been reported for the first time. The direct wide band gaps, structural stability, thermal stability, large Seebeck coefficients and figure of merit (close to unity) of these lead-free indium-silver based double perovskites suggest various thermoelectric device applications and thermoelectric power generation schemes.