DFT investigations of pressure effect on lead-free double perovskites Cs2ZrCl6 and Cs2ZrBr6: Structural stability and band gap evolution

Perovskites have piqued the interest of many people due to their exceptional properties and promising appli-cations. In this paper, the effect of pressure on lead-free double perovskites Cs2ZrCl6 is investigated using first -principles calculations. It demonstrates that Cs2ZrCl6 is stable up to 75 GPa, and that the alternation of the charge density distribution on the conduction bands caused by external pressure can force Cs2ZrCl6 to transform from an indirect band gap semiconductor to a direct band gap semiconductor, which is applicable for isostructural Cs2ZrBr6. This suggests that Cs2ZrCl6 and Cs2ZrBr6 have promising underlying applications in high-pressure environments. This work is also useful for designing novel perovskites with superior performance.

Automated summary

This study investigated the effect of pressure on Cs2ZrCl6 using first-principles calculations, finding that Cs2ZrCl6 is stable up to 75 GPa and that external pressure can alter the charge density distribution on the conduction bands, transforming it from an indirect band gap semiconductor to a direct band gap semiconductor. This research has implications for designing novel perovskites with superior performance.