title: Enhancing Perovskite Solar Cell Performance by Interface Engineering Using CH3NH3PbBr0.9I2.1 Quantum Dots.
abstract: To improve the interfacial charge transfer that is crucial to the performance of perovskite solar cells, the interface engineering in a device should be rationally designed. Here we have developed an interface engineering method to tune the photovoltaic performance of planar-heterojunction perovskite solar cells by incorporating MAPbBr3-xIx (MA = CH3NH3) quantum dots (QDs) between the MAPbI3 perovskite film and the hole-transporting material (HTM) layer. By adjustment of the Br:I ratio, the as-synthesized MAPbBr3-xIx QDs show tunable fluorescence and band edge positions. When the valence band (VB) edge of MAPbBr3-xIx QDs is located below that of the MAPbI3 perovskite, the hole transfer from the MAPbI3 perovskite film to the HTM layer is hindered, and hence, the power conversion efficiency decreases. In contrast, when the VB edge of MAPbBr3-xIx QDs is located between the VB edge of the MAPbI3 perovskite film and the highest occupied molecular orbital of the HTM layer, the hole transfer from the MAPbI3 perovskite film to the HTM layer is well-facilitated, resulting in significant improvements in the fill factor, short-circuit photocurrent, and power conversion efficiency.
authors.affiliation: Department of Chemistry, Laboratory of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , 2205 Songhu Road, Shanghai 200438, China.
authors.forename: Mingyang
authors.initials: M
authors.lastname: Cha
authors.affiliation: Department of Chemistry, Laboratory of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , 2205 Songhu Road, Shanghai 200438, China.
authors.forename: Peimei
authors.initials: P
authors.lastname: Da
authors.affiliation: State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Fudan University , 220 Handan Road, Shanghai 200433, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Fudan University , 220 Handan Road, Shanghai 200433, China.
authors.forename: Weiyi
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Fudan University , 220 Handan Road, Shanghai 200433, China.
authors.forename: Zhanghai
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Fudan University , 220 Handan Road, Shanghai 200433, China.
authors.forename: Faxian
authors.initials: F
authors.lastname: Xiu
authors.affiliation: Department of Chemistry, Laboratory of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , 2205 Songhu Road, Shanghai 200438, China.
authors.forename: Gengfeng
authors.initials: G
authors.lastname: Zheng
authors.affiliation: Department of Chemistry, Laboratory of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , 2205 Songhu Road, Shanghai 200438, China.
authors.forename: Zhong-Sheng
authors.initials: ZS
authors.lastname: Wang