ИСТИНА

In this contribution, we report on the synthesis of a series of fullerene derivatives and their systematic investigation as promising ETL materials for p-i-n perovskite solar cells. Devices fabricated using new fullerene derivatives F5-F10 demonstrated power conversion efficiencies up to 19.0%, which are higher than the reference cells assembled using PC61BM, which is a benchmark ETL material (14.0%). The improved photovoltaic performance of the devices incorporating new fullerenes derivatives originated from the decreased nonradiative recombination at the Cs0.12FA0.88PbI3/ETLs interface, efficient electron extraction, and full coverage of the perovskite absorber layer. Furthermore, our unencapsulated devices based on F6, F8, and F9 exhibited longterm stability under 1 sun for ~1300 h, whereas the initial PCE of PC61BM was degraded to ~ 40 % after 200 h under the same aging conditions. These obtained results feature new functionalized fullerene derivatives as promising ETLs for efficient and potentially stable perovskite solar cells.