The Controlling Mechanism for Potential Loss in CH₃NH₃PbBr₃ Hybrid Solar Cells

We investigated moisture and thermal stability of MAPbBr 3 perovskite material. Cubic MAPbBr 3 was found to be moisture-insensitive and can avoid the thermal stability issues introduced by low-temperature phase transition in MAPbI 3 . MAPbBr 3 and MAPbI 3 hybrid solar cells with efficiencies of ∼7.1% and ∼15.5%, respectively, were fabricated, and we identified the correlation between the working temperature, light intensity, and the photovoltaic performance. No charge-carrier transport barriers were found in the MAPbBr 3 and MAPbI 3 solar cells. The MAPbBr 3 solar cell displays a better stability under high working temperature because of its close-packed crystal structure. Temperature-dependent photocurrent–voltage characteristics indicate that, unlike the MAPbI 3 solar cell with an activation energy ( E A ) nearly equal to its band gap ( E g ), the E A for the MAPbBr 3 solar cell is much lower than its E g . This indicates that a high interface recombination process limits the photovoltage and consequently the device performance of the MAPbBr 3 solar cell.