Stable and high efficiency mixed-cation lead-based halide perovskite: A theoretical study

Abstract In this study, the stability and optoelectronic properties of DMA-doped α-MAPbI3 (DMA = CH3NH2CH3, MA = CH3NH3) have been explored in detail based on first-principles calculations. The results suggest that 12.5% DMA doping improves greatly the structural stability of α-MAPbI3, which indicates that α-MA0.875DMA0.125PbI3 may be stable at room temperature. The calculated band gap of α-MA0.875DMA0.125PbI3 is slightly larger than those of pure α-MAPbI3 and β-MAPbI3, which agrees well with the recent experimental value. In the visible light region, this material exhibits strong optical absorption coefficient. The predicted maximum power conversion efficiency of 20.46% is obtained for α-MA0.875DMA0.125PbI3. These results are useful for exploring stable and high efficiency lead-based perovskite materials in solar cells.