Core-expanded naphthalenediimide derivatives as non-fullerene electron transport materials for inverted perovskite solar cells

Core-expanded naphthalenediimide derivatives NDI3HU-DTYM and (DTYM-NDI-DTYA)2 with coplanar and twisted molecular backbones, respectively, and high electron mobility were employed as efficient low-temperature solution-processed non-fullerene electron transport materials for inverted perovskite solar cells. High device performance with a power conversion efficiency of 12.9% was achieved for (DTYM-NDI-DTYA)2-based perovskite solar cells, which can rival that of PCBM-based control devices.198