The effect of doping CaBr2 on the CsPbBr3 film for photovoltaic application

All-inorganic perovskite CsPbBr3 has gained widespread attention for photovoltaic application due to its preeminent stability. However, the conversion efficiency of CsPbBr3 solar cell is relatively low. Herein, a novel doping strategy has been employed in CsPbBr3 solar cell, which generates multiple benefits to enhance the cell performance. After doping CaBr2, carbon-based CsPbBr3 solar cell achieves a higher efficiency of 2.48%. The mechanism behind the efficiency improvement is that CaBr2-doped CsPbBr3 films have higher crystallinity, smaller optical band gap, and lower carrier recombination probability. This work opens up a simple and efficient method for enhancing the photovoltaic performance of all-inorganic perovskite solar cell.