Performance improvement of simplified CsPbBr₃ perovskite solar cell with doping BaBr₂

All-inorganic CsPbBr₃ perovskite solar cells have attracted increasing attention due to their long-term stability. Here, all-inorganic CsPbBr₃ perovskites are doped with BaBr₂ to improve the efficiency of perovskite solar cells. The CsPbBr₃ perovskite film displays better crystallinity, higher valence band maximum (VBM) position and lower carrier recombination probability after introducing BaBr₂. Hence, the electron-hole transport layer-free device with the presence of BaBr₂ achieves the improvement of the efficiency and stability. In particular, the efficiency of the device enhances from 1.88% to 2.86% by optimizing the doping concentration of BaBr₂. In addition, the BaBr₂-doped device without encapsulation exhibits excellent performance in air with relative humidity of ~80%.