Study of vacancy ordered double perovskites In2PtX6 (X = Cl, Br, I) for solar cells and renewable energy, alternative of hybrid perovskites

Abstract

The electronic, thermoelectric, and optical behavior of vacancy-ordered double perovskites In2PtX6 (X ​= ​Cl, Br, I) have been addressed using density functional theory for energy applications. The tolerance factor has been computed for structural stability, formation energy for thermal stability, and phonon dispersion for dynamic stability. The band structures ensure the band gaps of 2.0 ​eV, 1.96 ​eV, and 1.30 ​eV for In2PtCl6, In2PtBr6, and In2PtI6, respectively. The absorption of light energy is maximum in the ultraviolet region for In2PtCl6 and in the visible region for In2PtBr6 and In2PtI6. Moreover, light reflection and optical energy loss had also been computed. Thermoelectric behavior has been calculated by conductivities and Seebeck coefficient in terms of chemical potential and temperature. The figure of merit ranging from 0.80 to 1.0 in low temperature to room temperature emphasises their importance for thermoelectric applications. The elastic constants confirm mechanical stability and ductile nature. The high melting temperature, hardness, and ultralow lattice thermal conductivity increase the potential of study for device fabrication.