Spherical Hole-Transporting Interfacial Layer Passivated Defect for Inverted NiO-Based Planar Perovskite Solar Cells with High Efficiency of over 20.

In this study, we achieved a facile and low-cost (18-22 USD/g) synthesis of spiro[fluorene-9,9-phenanthren-10-one]-based interfacial layer materials (; designated , , , and ). Carbazoles and dimethylacridine substituents with an extended π-conjugation achieved through ortho- or para-orientations were used as donors at the spiro[fluorene-9,9'-phenanthren-10'-one] moiety. Highly efficient and stable inverted perovskite solar cells (PSCs) with the device architecture of ITO/NiO//perovskite/PCBM/BCP/Ag can be achieved to improve the surface morphology of NiO when are adopted as the interfacial layer.