Graphene for the Potential Renewable Energy Applications

Abstract

To combat the challenge of the upcoming energy crisis due to the shortage of fossil fuel and the global warming issue, it is evidently needed to use the non-conventional energy sources. Among the many sources, solar energy is the most popular alternative source since it is cheapest and convenient to harvest energy from sunlight. Although the conversion efficiency of the generally used conventional solar cells are not very good, in recent advancement of solar cell technology, the use of graphene has shown a 20% reduction in the reflectance of solar irradiation causing a significant increase in efficiency up to 20%. Based on the application of graphene, many different types of graphene solar cells have been developed. Basically, graphene is applied to photovoltaic cells as transparent electrode, catalytic counter electrode, Schottky junction, and electron or hole or both electron–hole transport layers. The overall power conversion efficiency also changes according to the application type. For example, with graphene/silicon solar cells, the highest efficiency obtained is 15.6% whereas in solar cell made with graphene quantum dot and P3HT, the efficiency achieved is up to 1.28%. With perovskite-based graphene solar cells, the conversion efficiency can be reached up to as high as 23.3%. So, various types of solar cells and what are the roles of graphene there are discussed in this chapter.