Carbon-based electrodes for perovskite solar cells

The cost-effective processability and high stability of carbon-based perovskite solar cells (C-PSCs) have shown great potential to positively devote to the development of large-scale production processes. However, there are certain critical issues such as inferior performance and poor interface contact between perovskites and carbon electrodes, which have to be resolved first. The review shows that three main carbon materials, namely, carbon black, graphenes and carbon nanotubes display high photoelectric conversion efficiencies when being mixedly used as rigid electrodes and show excellent robustness in mechanical deformation as flexible carbon electrodes in carbon-based perovskite solar cells. Moreover, the specific development of and the comparison among three primary types of C-PSCs, namely, meso C-PSCs, embedment C-PSCs and paintable PSCs are emphasized. Furthermore, this work discusses the latest progress of C-PSC interface engineering from four aspects, namely, energy alignment, hysteresis effect, interface passivation and built-in electric field, and the differences among them are explained. Finally, further challenges and perspectives of C-PSCs are outlined. This work will be a profound influence and guidance on the significance of C-PSCs in commercialization.