New insights into a first principle calculation and experimental study of Sn-Pb-Ge ternary-metal perovskites for potential photovoltaic application

To replace Pb with a less toxic metal is a key scientific challenge because of the toxicity of Pb and the most viable replacement are Sn and Ge. In this study, we propose Sn-Pb-Ge ternary-metal perovskites CH3NH3SnxPbyGe1-x-yI3 (0 < x, y < 1) for the first time. For the identification of new families, the features were verified by fist principle calculations from a theoretical perspective, especially the structural and electric performance, optical property and crystal structure. The Sn-Pb-Ge ternary-metal perovskites are prepared for from the aqueous HI/H3PO2 solvent mixture the first time, For CH3NH3Sn0.25Pb0.5Ge0.25I3, the computed results are in good agreement with the experimental data, which provide a clear-sighted insight into the design of environmentally friendly perovskites for potential electrical and tunable optical application.