Defect Passivation by Amide-Based Hole-Transporting Interfacial Layer Enhanced Perovskite Grain Growth for Efficient p-i-n Perovskite Solar Cells.

In this study, we synthesized four acceptor-donor-acceptor type hole-transporting materials (HTMs) of for an HTMs/interfacial layer with carbazole as the core moiety and ester/amide as the acceptor unit. These HTMs contain 4-hexyloxyphenyl substituents on the carbazole N atom, with extended π-conjugation achieved through phenylene and thiophene units at the 3,6-positions of the carbazole. When using amide-based HTMs as a dopant-free HTM in a p-i-n perovskite solar cell (PSC), we achieved a power conversion efficiency (PCE) of 13.