Recent advancement in the performance of solar cells by incorporating transition metal dichalcogenides as counter electrode and photoabsorber

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) architectures have revealed fascinating characteristics such as direct band gap, strong light absorption, and novel electrochemical properties, which make them promising materials for photovoltaic applications. The review focuses on (1) the study of electrochemical and photovoltaic properties of TMDCs thereby using them as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) and (2) analyzing the light absorption and charge transport performance of TMDCs heterostructures with different 3D materials. We have further investigated different materials in combination with TMDCs such as reduced graphene oxide nanocomposite, graphene flakes, and molybdenum as CEs in DSSCs. Conventionally, platinum (Pt) is used as a CE material for DSSCs that displays excellent catalytic activity and high electrical conductivity but due to the high cost and scarcity of Pt limits the large-scale production. Therefore, the excellent electrochemical properties and cost-effectiveness of TMDCs make them promising contender to replace Pt as CEs in DSSCs. Additionally, the photovoltaic properties of TMDCs and their heterostructures with various materials such as silicon, gallium arsenide, indium phosphate, tungsten disulfide, boron nitride, and organic polymers are reviewed. TMDCs are also investigated as hole transport layer (HTL) and electron transport layer (ETL) with various organic polymers such as P3HT, PCBM, PEDOT:PSS, PTB7, and spiro-OmeTAD for organic and perovskite-based solar cells (SCs). The utilization of TMDCs as CEs and photoabsorbers enhances the power conversion efficiency (PCE) to generate cost-effective and high performance SC devices that can be exploit for future technological applications.