title: Generalized colloidal synthesis of high-quality, two-dimensional cesium lead halide perovskite nanosheets and their applications in photodetectors.
abstract: All-inorganic cesium lead halide perovskite (CsPbX3, X = Cl, Br, and I) nanocrystals (NCs) are emerging as an important class of semiconductor materials with superior photophysical properties and wide potential applications in optoelectronic devices. So far, only a few studies have been conducted to control the shape and geometry of CsPbX3 NCs. Here we report a general approach to directly synthesize two-dimensional (2D) CsPbX3 perovskite and mixed perovskite nanosheets with uniform and ultrathin thicknesses down to a few monolayers. The key to the high-yield synthesis of perovskite nanosheets is the development of a new Cs-oleate precursor. The as-synthesized CsPbX3 nanosheets exhibit bright photoluminescence with broad wavelength tunability by composition modulation. The excellent optoelectronic properties of CsPbX3 nanosheets combined with their unique 2D geometry and large lateral dimensions make them ideal building blocks for building functional devices. To demonstrate their potential applications in optoelectronics, photodetectors based on CsPbBr3 nanosheets are fabricated, which exhibit high on/off ratios with a fast response time.
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China. yangdong@fudan.edu.cn and Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Department of Chemistry, Fudan University, Shanghai 200433, China. agdong@fudan.edu.cn.
authors.forename: Longfei
authors.initials: L
authors.lastname: Lv
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Department of Chemistry, Fudan University, Shanghai 200433, China. agdong@fudan.edu.cn.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Xu
authors.affiliation: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China. wdhu@mail.sitp.ac.cn.
authors.forename: Hehai
authors.initials: H
authors.lastname: Fang
authors.affiliation: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China. wdhu@mail.sitp.ac.cn.
authors.forename: Wenjin
authors.initials: W
authors.lastname: Luo
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Department of Chemistry, Fudan University, Shanghai 200433, China. agdong@fudan.edu.cn.
authors.forename: Fangjie
authors.initials: F
authors.lastname: Xu
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Department of Chemistry, Fudan University, Shanghai 200433, China. agdong@fudan.edu.cn.
authors.forename: Limin
authors.initials: L
authors.lastname: Liu
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Department of Chemistry, Fudan University, Shanghai 200433, China. agdong@fudan.edu.cn.
authors.forename: Biwei
authors.initials: B
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China. yangdong@fudan.edu.cn.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China. yangdong@fudan.edu.cn.
authors.forename: Dong
authors.initials: D
authors.lastname: Yang
authors.affiliation: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China. wdhu@mail.sitp.ac.cn.
authors.forename: Weida
authors.initials: W
authors.lastname: Hu
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Department of Chemistry, Fudan University, Shanghai 200433, China. agdong@fudan.edu.cn.
authors.forename: Angang
authors.initials: A
authors.lastname: Dong