Discovery of Pb-Free Perovskite Solar Cells via High-Throughput Simulation on the K Computer.

We performed a systematic high-throughput simulation with density functional theory for 11 025 compositions of hybrid organic-inorganic halide compounds in ABX3 and A2BB'X6 forms, where A is an organic or inorganic component, B/B' is a metal atom, and X is a halogen atom. The computational results were compiled as a materials database. We performed massive computational simulation by using the K computer, which is a massively parallel many-core supercomputer in Japan. By applying the screening procedure to all the compounds in the materials database, we discovered novel candidates for environmentally friendly lead-free perovskite solar cells and propose 51 low-toxic halide single and double perovskites, most of which are newly proposed in this study. The proposed low-toxic halide double perovskites are classified under six families: group-14-group-14, group-13-group-15, group-11-group-11, group-9-group-13, group-11-group-13, and group-11-group-15 double perovskites.