Recent progress in the role of two‐dimensional materials as an efficient charge transport layer in perovskite solar cells

Lead halide perovskite has been found to be a promising contender for photovoltaic (PV) applications. Solution-processed perovskite solar cells (PSCs) have attracted excessive consideration owing to their high performance and low manufacture cost. However, complicated deposition of expensive metal electrodes is incompatible with large-scale and low-cost fabrication of perovskite PV devices and thus hinders their commercialization. Various combinations of the materials have been used as hole transport layer (HTL) and electron transport layer (ETL) to enhance the conversion efficiency and stability of PSCs. In this regard, layered two-dimensional materials like graphene and transition metal dichalcogenides (TMDCs) have revealed fascinating properties that make them a promising material for PV applications. The review focuses on the applications of 2D materials thereby using them as HTL and ETL in PSCs. We have discussed the effect of Gr and graphene quantum dots (GQDs) as HTL in composition with frequently used ZnO and TiO2. Furthermore, the role of TMDCs like MoS2, WS2 as ETL, and HTL have been studied. Besides, the effect of the synthesis approach on PV performance is also discussed. The ultrasonic spray pyrolysis method for the synthesis of MoS2 has made an effective impact on PV performance of the cell. A detailed study of TMDCs with organic HTLs like P3HT and so on is also provided. Therefore, the utilization of layered 2D materials as HTL and ETL in PSCs enhances the overall power conversion efficiency (PCE) of the device, facilitating the fast charge transport and provides high thermal and mechanical stability. Thus, the combination of strong light absorber with highly conductive layered materials can be exploited as a promising contender for efficient, stable, and cost-effective solar cells for future energy harvesting technological applications.