title: Controlled Substitution of Chlorine for Iodine in Single-Crystal Nanofibers of Mixed Perovskite MAPbI3- x Clx.
abstract: Longer carrier diffusion length and improved power conversion efficiency have been reported for thin-film solar cell of organolead mixed-halide perovskite MAPbI3- x Cl x in comparison with MAPbI3 . Instead of substituting I in the MAPbI3 lattice, Cl-incorporation has been shown to mainly improve the film morphology of perovskite absorber. Well-defined crystal structure, adjustable composition (x), and regular morphology, remains a formidable task. Herein, a facile solution-assembly method is reported for synthesizing single-crystalline nanofibers (NFs) of tetragonal-lattice MAPbI3- x Cl x with the Cl-content adjustable between 0 ≤ x ≤ 0.75, leading to a gradual blueshift of the absorption and photoluminescence maxima from x = 0 to 0.75. The photoresponsivity (R) of MAPbI3 NFs keeps almost unchanging at a value independent of the white-light illumination intensity (P). In contrast, R of MAPbI3- x Cl x NFs decreases rapidly with increasing both the x and P values, indicating Cl-substitution increases the recombination traps of photogenerated free electrons and holes. This study provides a model system to examine the role of extrinsic Cl ions in both perovskite crystallography and optoelectronic properties.
authors.affiliation: Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China.
authors.forename: Haihua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Liao
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
authors.forename: Xuedong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China.
authors.forename: Ke
authors.initials: K
authors.lastname: Hu
authors.affiliation: Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China.|Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
authors.forename: Jiannian
authors.initials: J
authors.lastname: Yao
authors.affiliation: Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China.|Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.|Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Tianjin University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, P. R. China.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Fu
keywords: MAPbI3-xClx; nanofibers; perovskite; photodetectors; self-assembly