The roles of graphene and its derivatives in perovskite solar cells: A review

With the rapid demand growth of green energy technologies, solar cell has been considered as a very promising technology to address current energy and environmental issues. Among them, perovskite solar cells (PSCs) have attracted much research interest in recent years due to the prominent advantages of light weight, good flexibility, low cost, and comparable power conversion efficiency (PCE) to that of traditional commercial solar cells (ie, amorphous silicon, GaAs, and CdTe). Meanwhile, elemental two-dimensional (2D) graphene and its derivatives, which possess the outstanding advantages of abundant functional groups, good environmental stability, and good compactness, have been extensively studied on the integration with PSC devices. The review introduces the properties and preparation methods of graphene and its derivatives, and the applications in PSC are summarized in detail. Ultimately, the critical challenges and prospects for the further development of graphene and its derivatives in PSCs are discussed.