Low-temperature electrospray-processed SnO₂ nanosheets as an electron transporting layer for stable and...

Semiconducting metal oxide electron transporting layers (ETLs) with distinct morphologies have the ability to produce the less-hysteric and high efficiency perovskite solar cells (PSCs). Here, for the first time we introduce a viable electrospraying route for one-step deposition of highly mesoporous SnO₂ nanosheets, as the ETLs in PSCs with reduces hysteresis, high charge collection efficiency and improved ambient stability. Furthermore, optimization of the interfacial properties between the SnO₂ nanosheets and the perovskite absorber layer by the employment of a C60 interlayer consequences in decreasing the charge recombination, better energy level alignment, and significantly improved power conversion efficiency (PCE). Consequently, the efficient PSCs based on C60-modified SnO₂ nanosheets ETLs have almost hysteresis-free behavior, with a best PCE of 20.2% thanks to the highly porous nature of nanosheets and better perovskite infiltration. This study reveals that hierarchical SnO₂ is a possible ETL for producing low-cost and efficient PSCs with long-term stability.