**3. Conclusions**

2D atom thick TMD promises facile charge extraction and transport in the perovskite solar cells due to its ultimate thin and single-crystalline nature. The optimization of the 2D TMD layer to obtain a large dimension on the substrate surface is necessary to further promote a highly dynamic photogenerated carrier in the perovskite solar cells device. These materials may become a potential platform for high-performance perovskite solar cells.
