Interface Engineering for Perovskite Solar Cells

In this chapter, the authors use the rapidly rising Perovskite Solar Cells (PSCs) as a case to illustrate the rich facets of material interface engineering. In order to achieve highly efficient PSCs, numerous works have mainly focused on the design of new materials and device structures, and the control over perovskite film quality. It appears impending now that interface engineering still has a big, untapped role to play for enhancing both efficiency and stability of PSCs. The perovskite/ETL interface is related to electron extraction, hysteresis, and device stability in inverted p-i-n PSCs. PCBM is the widely used electron transport layer in inverted structure devices. However, due to the insufficient viscous solution for spin coating caused by the small molecule of PCBM, it was difficult to form a high-quality PCBM film on the relatively rough perovskite surface in the earlier stage of the inverted structure device fabrication, which thus induced the inefficient interface charge transfer.