Efficient and stable hybrid conjugated polymer/perovskite quantum dot solar cells

Emerging lead halide perovskite quantum dots (QDs) have attracted great research interest relative to conventional metal chalcogenide-based QDs for applications like solar cells. Meanwhile, such a new type of solution-processable inorganic QD also provides an additional platform to design high performance organic-inorganic hybrid films to maximize their device performance. Herein, we report a hybrid strategy utilizing conjugated polyelectrolyte PFN-Br and all-inorganic CsPbI3 perovskite QDs. There is an urgency to further improve the electronic coupling as well as the ambient stability of CsPbI3 QDs. Using the hybrid strategy, we demonstrated that the hydrophobic PFN-Br can well passivate the CsPbI3 QD surface to reduce defect states as well as suppress the migration of halide ions for better stability. Consequently, the hybrid PFN-Br/CsPbI3 QD solar cell delivers a champion efficiency of 15.07%, outperforming that of 13.31% in the pristine CsPbI3 QD based one. Moreover, the hybrid blend film exhibits significantly improved storage stability under ambient conditions. We believe that these results would provide a new design principle for hybrid organic-inorganic systems for high-performance optoelectronic devices.