Bi₂S₃ Nanocrystal–CsPbBr₃ Hybrid Absorber Enables Durable and Efficient Carbon-Based Perovskite Solar Cells

The high-quality absorber with improved light absorption ability and crystallinity plays a critical role in enhancing the photovoltaic performance of CsPbBr 3 -based solar cells. This work developed a Bi 2 S 3 nanocrystal–CsPbBr 3 hybrid absorber to improve the photovoltaic performance of perovskite solar cells (PSCs) by taking advantages of both CsPbBr 3 and Bi 2 S 3 . The as-synthesized Bi 2 S 3 nanocrystals with different structures, including quantum dots (QDs) and nanorods (NRs), were applied as the hybridizer of CsPbBr 3 by embedding them into the CsPbBr 3 matrix, respectively, while the Bi 2 S 3 QDs and NRs were prepared just by adjusting the synthesized times. Ultimately, the CsPbBr 3 –Bi 2 S 3 NR hybrid absorber enables carbon-based PSCs (C-PSCs) to achieve a champion power conversion efficiency (PCE) of 9.37%, which presents an improvement of 19.7% compared with the PCE of the device based on the pristine CsPbBr 3 absorber. The improved photovoltaic performance originated from the enhanced crystallinity, reduced surface defects, broadened light response region in the hybrid absorber, and enhanced carrier separation/transport process in the device. This study provides valuable guidance for the design and assembly of nanocrystal–perovskite hybrid absorbers to improve the photovoltaic performance of CsPbBr 3 -based solar cells.