One-step synthesis of low-cost perylenediimide-based cathode interfacial materials for efficient inverted perovskite solar cells

Perylene diimide-based small molecular (PDI-4N) was designed and synthesized through a smiple one-step reaction as efficient cathode interface layers (CIL) in inverted PVSC, and PDI-2N was also synthesized as a contrast. Multi-dimethyl amine groups in the N- and bay- positions of PDI-4N give PDI4N better alcohol solubility, higher conductivity, electron mobility, self-doping property. Corresponding inverted PVSC with PDI-4N CIL manifests a promising power conversion efficiency (PCE) of 21.33%, and synthetic complexity (SC) and industrial figure of merit (IFOM) of PDI-4N are very low than many other cathode interface materials having been reported. Moreover, good stability with a PCE loss of only ∼2.0 % after 600 h is also obtained for PDI-4N based device.