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Air molecules in XPbI3 (X=MA, FA, Cs) perovskite: A degradation mechanism based on first-principles calculations

The power conversion efficiency of organic–inorganic halide perovskite solar cells is exceeding 22%. However, their potential for low cost and facile fabrication process needs to overcome barriers related to environmental stability and compatibility. Herein, using first-principles calculations, we studied the structural and electronic properties of air molecules (H2O, O2, N2, and CO2) in MAPbI3 and FAPbI3. Both formation energy and electronic band structures show large differences for H2O and O2 in these perovskites. In addition, the stability of inorganic perovskite, CsPbI3, was investigated and compared with the aforementioned organic ones. Based on the degradation mechanisms revealed by crosswise comparative analysis here, possible routes can be developed to stabilize the hybrid perovskite solar cells and thus accelerate their commercial applications.