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ArticleGraded Bandgap CsPbI2+xBr1−x Perovskite Solar Cells with a Stabilized Efficiency of 14.4%
Context & Scale
Recently, metal halide perovskite has attracted a surge of research interest for its excellent optoelectronic properties. Particularly, all-inorganic perovskite shows great potential for photovoltaic commercialization due to its excellent atmospheric stability. Here, a CsPbI2+xBr1−x perovskite solar cell with a graded bandgap is first explored using CsPbBrI2 and CsPbI3 quantum dots (QDs) as component cells. Meanwhile, several optimizations were conducted to boost the device performance. Upon optimization the extended photoresponse, high carrier mobility, and well-matched energy levels together afford a power conversion efficiency (PCE) as high as 14.45%. To our knowledge, this is the highest PCE for inorganic perovskite solar cells. We believe the reported strategy presents a novel and promising method to design other optoelectronic devices with high performance and reliability.