Molecular engineering of conjugated polymers for efficient hole transport and defect passivation in perovskite solar cells

A series of carbazole and benzothiadiazole (BT) based copolymers have been employed as the dopant-free hole transport materials (HTMs) for perovskite solar cells. The side-chains of these HTM can reduce the π−π stacking structural order but can also introduce desired defect passivation effect.253