MoS₂ Nanoflakes/Perovskite Active Layer Enhances Performance and Stability in Perovskite Solar Cells

We developed planar perovskite solar cells (PSCs) by incorporating vertical molybdenum disulfide (MoS2) nanoflakes with CH3NH3PbI3 perovskite via thermal chemical vapor deposition. These cells showed enhanced performance, improved stability, and cost-effectiveness, achieving a power conversion efficiency (PCE) of 15.6% and maintaining 89% of its initial efficiency after 500 h of ambient storage under 1 sun solar illumination conditions. Integration of MoS2 not only improved solar absorption and carrier generation but also facilitated charge carrier separation and transport in the device. This was achieved by reducing interfacial carrier recombination, as evidenced by decreased charge transfer resistances. Additionally, the addition of fluorinated graphene oxide (FGO) as a hole transport layer further improved stability and reduced hysteresis, leading to a notable 40% increase in PCE compared to that of reference cells without MoS2 nanoflakes. The synergistic effect of MoS2 incorporation and interface engineering significantly enhanced the performance of the PSCs. Furthermore, FGO provided efficient hole transport and electron blocking properties, enhancing device stability. The inclusion of FGO not only mitigated leakage current but also improved device stability due to its intrinsically stable crystal structure. These findings demonstrate the potential of MoS2 nanoflakes/CH3NH3PbI3 as a hybrid active layer for PSCs, offering a pathway toward cost-effective, stable, and high-performance solar energy conversion.