The Potential of Graphene as an ITO Replacement in Organic Solar Cells: An Optical Perspective

Graphene possesses innate potential to replace indium tin oxide (ITO) as the transparent electrode in an organic solar cell device. From our transmittance study weighted with the air mass 1.5 global (AM1.5G) solar spectrum, it is found that a higher transparency may be obtained for up to four layers of graphene in comparison to ITO. Our findings suggest that replacing ITO with monolayer graphene in organic solar cells yields comparable performance. Due to the increased optical absorption, organic solar cells with four-layer graphene (with the same sheet resistance as ITO at 30 Omega/square) are capable of attaining at least 92% of the same organic photovoltaic device with an optimized ITO electrode for both normal and angular AM1.5G illumination.