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.