Abstract The newly discovered inorganic lead-free double perovskites (A2BB’X6) are comparable to, and suitable replacements to the currently-popular hybrid lead perovskites. These double perovskites demonstrate strong potential for optoelectronic and photo-voltaic applications due to their lead-free low environmental impact, low cost, and reliability. However, this material’s native wide bandgap limits its potential as a solar cell material. In this paper, we theoretically tune the bandgap of various double perovskite materials under high pressure to attempt to improve efficiency, without changing the composition of the materials and thus conserving their environmentally friendly properties. Our results show that after compressing the parameters by nearly 11%, the bandgaps of the materials Cs2AgBiBr6 and Cs2SbAgCl6 dropped from 2.3 eV to approximately 1.55 eV, optimizing their efficiency as perovskites. This work encourages further research into the engineering of bandgaps and novel double perovskite devices for photo-voltaic applications.
E.Joo Yang, Xuan Luo