Low-temperature processed bipolar metal oxide charge transporting layers for highly efficient perovskite solar cells

Metal oxide charge carrier transporting materials have been incorporated in many ways perovskite solar cells (PSCs) because of their excellent chemical stability, wide band gaps, and reasonable mobilities. Herein, we report a low-temperature solution-processed intercalation method for introducing metal oxides displaying bipolar capability into PSCs. We intercalated p-type nickel (NiO) with cesium carbonate (Cs2CO3) to function as hole electron transport layers inverted (p–i–n) conventional planar (n–i–p) PSCs, respectively. When compared the corresponding NiO-only layer, Cs2CO3-intercalated NiO layer displayed enhanced extraction without sacrificing its capability. The power conversion efficiencies PSCs reached high 12.08 13.98%, This approach not only realizes capacity but also opens up possible route preparing interconnecting tandem optoelectronics.