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

Abstract

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.