1D Versus 2D Carbon Nanostructures for Flexible and Ultrathin Solar Cells

The development of flexible and ultrathin solar cells, which has various benefits including light weight, compatibility with roll-to-roll fabrication, tolerance to deformation, presence of curved surfaces, etc., represents a recent advancement in the photovoltaic (PV) domain. The vast application areas of these flexible and ultrathin solar cells include portable and wearable electronic devices, indoor photovoltaic systems, automobile, space and textile manufacturing fields, etc. Flexible and ultrathin solar cells can be developed under different categories, namely, dye-sensitized solar cells, organic solar cells, and perovskite solar cells. In this context, carbon nanostructures including carbon nanotubes, fullerene, carbon quantum dots, and graphene can be employed as the light absorber material, transport material, or even as an electrode material in all these categories of solar cells owing to their extraordinary conductivity, long-term stability, flexibility, and tunable bandgap. This chapter focuses on the use of aforementioned carbon nanostructures in dye-sensitized, organic and perovskite solar cells and the effect of dimensionality of carbon nanostructures on the performance of photovoltaic cells. The chapter also reviews the limitations of 1D and 2D carbon nanostructures when employed in such solar cell device architectures and their future perspectives also.