Conjugated polyelectrolyte with potassium cations enables inverted perovskite solar cells with an efficiency over 20%

摘要： Defect-passivation functional groups have been extensively explored in perovskite solar cells (PSCs) in recent years; however, most of these groups were organic, and the integration of inorganic functional groups with organic matrixes bearing other functions has rarely been reported. Here, to demonstrate the effective of this integration, the coalition of an inorganic group, K+ ion, and an organic conjugated polyelectrolyte (CPE) matrix which serves as a hole transporting material (HTM) is attempted. The resulting CPE material TB(K) presents much stronger ability of defect-passivation and hole extraction, and thus yields a much lifted power conversion efficiency (PCE) of 20.01% and an increased long-term stability when applied in the inverted PSC devices compared with its control polymer TB(Na), where only the inorganic cations are varied from a defect-passivation group to a common one.