Enhanced performance of BiI3-incorporated CsPbBr3 solar cells

CsPbBr3 all-inorganic perovskite solar cells (PSCs) have been extensively investigated due to their remarkable stability. However, their limited film quality and wide bandgap result in a low photoelectric conversion efficiency (PCE). In this study, BiI3 was incorporated into CsPbBr3 films to synergistically enhance light absorption and film quality. It was found that the partial substitution of Pb2+ and Br- with Bi3+ and I- in CsPbBr3 improved film quality, enhanced light absorption, and facilitated charge transfer and extraction. The device incorporating BiI3-incorporated CsPbBr3 as a light absorbing layer achieved an efficiency of 9.54%, exhibiting a significant enhancement of 19.4% compared to the undoped device. This work provides a new incorporating strategy that collaboratively improves light absorption and film quality.