ABSTRACT
Environmentally amenable renewable energy sources, such as biomass, solar, hydroelectric, wind, and hydrogen, are indispensable for the existence and development of social evolution. Amongst these sources, sunlight is plentiful and inexhaustible, and has gained considerable significance in recent energy research. This clean and sustainable form of energy can be effectively converted to electricity via the means of solar cells. Notably, the third-generation (3G) solar cells, such as dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs), find specific attention amongst the most sustainable technologies, due to their low cost with less carbon footprint. However, the impediment is to use materials that are inexpensive, ecological, and possess attractive properties for catalytic applications. In this regard, graphene, a one-atom thick, monolayer of graphite with a unique two-dimensional (2D) structure, is highly alluring. It has attracted significant research interest, owing to its exceptional electronic, thermal, mechanical, and charge transport properties. These remarkable features of graphene, along with the intrinsic characteristics of the carbon, make this honeycomb-structured material a promising candidate for various energy conversion and storage device applications. Over the past few years, significant effort has been made in the design and fabrication of graphene-based electrode materials for their extensive use in each part of solar cells (anode, cathode, electrolyte, and transparent conducting oxide layer) and has attained prodigious performance. This chapter summarizes the state-of-the-art research of different graphene-based materials that can play a diverse role as an active layer, sensitizer, counter-electrode, hole transport layer (HTL), and electron transport layer (ETL) in DSSC and PSC device applications. In this chapter, the synthesis, morphological features, properties, and performance of graphene and its related compounds, followed by the crucial issues, challenges, and future perspectives are addressed.
