Tetrahydroxy-Perylene Bisimide Embedded in a Zinc Oxide Thin Film as an Electron-Transporting Layer for High-Performance Non-Fullerene Organic Solar Cells.

By introduction of four hydroxy (HO) groups into the two perylene bisimide (PBI) bay areas, new HO-PBI ligands were obtained which upon deprotonation can complex Zn ions and photosensitize semiconductive zinc oxide thin films. Such coordination is beneficial for dispersing PBI photosensitizer molecules evenly into metal oxide films to fabricate organic-inorganic hybrid interlayers for organic solar cells. Supported by the photoconductive effect of the ZnO:HO-PBI hybrid interlayers, improved electron collection and transportation is achieved in fullerene and non-fullerene polymer solar cell devices, leading to remarkable power conversion efficiencies of up to 15.95 % for a non-fullerene based organic solar cell.