Self-assembled materials with an ordered hydrophilic bilayer for high performance inverted Perovskite solar cells

While self-assembled material based inverted perovskite solar cells have surpassed power conversion efficiencies of 26%, enhancing their performance in large-area configurations remains a significant challenge. In this work, we report a self-assembled material based hole-selective layer 4-(7H-dibenzo[c,g]carbazol-7-yl)phenyl)phosphonic acid, with a π-expanded conjugation. The enhanced intermolecular π–π interactions facilitate the self-assembly of 4-(7H-dibenzo[c,g]carbazol-7-yl)phenyl)phosphonic acid molecules to form an ordered bilayer with a hydrophilic surface, which passivates the buried perovskite interface defect and enables high-quality and large-area perovskite preparation, while simultaneously enhancing interfacial charge extraction and transport. The certified efficiency of 4-(7H-dibenzo[c,g]carbazol-7-yl)phenyl)phosphonic acid based small-area (0.0715 cm2) device is 26.39% with high stability. Furthermore, a certified efficiency of 25.21% is achieved for a 99.12 mm2 large area device. Qu et al. report a self-assembled material with π-expanded conjugation to form hydrophilic ordered bilayer as hole selective layer for inverted perovskite solar cells. The enhanced interfacial charge extraction and transport enable certified efficiency of 26.39% and 25.21% for 7.15 mm2 - and 99.12 mm2 -devices, respectively.