Optoelectronic and thermoelectric properties of Cs2PtX6 (X=Cl, Br, I) for energy conversion applications: DFT calculations

This research employs density functional theory within the WIEN2k framework to simulate Cs2PtX6 (X = Cl, Br, I) perovskites. The study focuses on assessing the structural stability and thermodynamic properties through the computation of tolerance factor and formation energies, affirming the viability of the simulated materials. Notably, this investigation reveals a direct bandgap semiconducting character of these compounds, with specific values of the bandgap of 2.9, 2.15, and 1.08 eV for Cl, Br, and I-based compositions, respectively. The analysis of optical behavior demonstrates a redshift in absorption edge and an increase in optical conductivity, correlating with the enlarging halogen size within the series. The investigation into the thermoelectric characteristics of Cs2PtX6 perovskites, which include sigma and kappa e as well as S, PF, and ZT, underscores the potential of Cs2PtX6 perovskites for deployment in thermal energy harvesting devices. Furthermore, the mechanical behavior assessment indicates the ductile nature of studied compounds, contributing to their overall mechanical stability. This study gives a comprehensive recognition of structural, electronic, mechanical, optical, and transport characteristics of Cs2PtX6 compounds, suggesting their promise for applications in advanced materials for optoelectronic and thermoelectric devices.