Self-assembled hole-transport material incorporating biphosphonic acid for dual-defect passivation in NiO_<i>x</i>-based perovskite solar cells

Abstract

The efficiency and stability of nickel oxide (NiO x )-based perovskite solar cells (PSCs) are critically hindered by defects and suboptimal charge transfer at the interface between perovskite crystals and the NiO x layer.