Optoelectronic and thermoelectric properties of double perovskite Rb2PtX6 (X = Cl, Br) for energy harvesting: First-principles investigations

Abstract

The double perovskite materials have attracted broad interest of researchers in recent years because of their potential applications in renewable energy. This work comprehensively explore optoelectronic and thermoelectric properties of Rb2PtCl6 and Rb2PtBr6 of double perovskite for renewable energy applications. The structural and thermodynamic stabilities are ensured by calculating their tolerance factor, formation energy and phonon dispersion. The Rb2PtCl6 and Rb2PtBr6 exhibited bandgaps of magnitude 2.62 and 2.10 eV. Maximum absorption occurred in the visible range for Rb2PtBr6, which shifted to the ultraviolet region when Br is replaced with Cl that ensures their effective utilization for solar cells and other optoelectronic applications. Furthermore, the thermoelectric behavior of these materials by semi-classical Boltzmann theory-based BoltzTraP code. The trends of thermoelectric parameters of Rb2PtBr6 deviate from the trends of Rb2PtCl6 at above 300 K. The figure of merit (ZT) reveals reasonable thermoelectric performance in the low-temperature zone. Our present study is believed to open an avenue of research for the potential applications in next-generation renewable energy devices.