Robust and Efficient Carbon-Based Planar Perovskite Solar Cells with a CsPbBr₃-MoS₂ Hybrid Absorber

Optical response improvement and hole transport/extraction enhancement are critical to enhancing the power conversion efficiency (PCE) of carbon electrode-based perovskite solar cells (C-PSCs) with an absorber of CsPbBr₃. In this study, a multifunctional optimization method by embedding MoS₂ nanosheets in CsPbBr₃ bulk to construct a perovskite-nanosheet hybrid structure was presented. A CsPbBr₃-MoS₂ hybrid film was fabricated by two-step spin-coating the precursor solutions of PbBr₂ and CsBr-MoS₂ under an ambient atmosphere, where the aqueous solution with highly distributed MoS₂ nanosheets was applied as a solvent of the hybrid precursor solution. MoS₂ nanosheets were utilized as a p-type modifier and extra absorber to hybridize with CsPbBr₃ for improving the CsPbBr₃-carbon interface and light absorption ability of the perovskite layer. As expected, the optical response ability, absorber film quality, and carrier separation/extraction/transport properties of C-PSCs were enhanced significantly by embedding MoS₂ nanosheets in CsPbBr₃ film, which resulted in enhanced C-PSCs properties. Finally, the C-PSCs with the structure of FTO/SnO₂/CsPbBr₃-MoS₂/C presented a champion PCE of 7.87% (active area: 1 cm²), which demonstrated excellent ambient and operational stability. This study provides an efficient method for constructing ultrastable C-PSCs by hybridizing perovskite and nanosheets.