title: Solution-processed highly bright and durable cesium lead halide perovskite light-emitting diodes.
abstract: Recently, CsPbBr3perovskites have been emerging as very promising green emission materials for light-emitting diodes (LEDs) due to their high color purity, low cost and high photoluminescence quantum yield (PLQY). However, the corresponding LED performance is still low and far behind CH3NH3PbBr3; it is due to the lack of proper perovskite film preparation methods and interfacial engineering. Herein, we report highly bright and durable CsPbBr3-based LEDs fabricated using a one-step solution method. The precursor solution is prepared by simply dissolving CsPbBr3powder and a CsBr additive in dimethyl sulfoxide (DMSO). We find that the CsBr additive not only significantly enhances the PLQY but also induces directional crystal growth into micro-plates, forming a smooth perovskite film for LEDs. LEDs employing such high quality films show a high luminance of 7276 cd m-2and high color purity with a full width at half maximum of 18 nm. Furthermore, the as-fabricated LEDs reveal an outstanding ambient stability with a decent luminance output (>100 cd m-2, steady increase without any degradation trend) for at least 15 h under a constant driving current density (66.7 mA cm-2). And we propose two reasons for this unique luminance increasing behavior: (1) the CsPbBr3perovskite is thermally stable and can survive from joule heat; and (2) on the other hand, the joule heating will induce interface or crystalline film annealing, reduce device resistance and then enhance the luminance output.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore. qihua@ntu.edu.sg and College of Materials Science & Engineering, Huaqiao University, Xiamen, Fujian, 361021 China. weizhanhua@hqu.edu.cn.
authors.forename: Zhanhua
authors.identifier: http://orcid.org/0000-0003-2687-0293
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Luminous! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore. hvdemir@ntu.edu.sg.
authors.forename: Ajay
authors.initials: A
authors.lastname: Perumal
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore. qihua@ntu.edu.sg.
authors.forename: Rui
authors.initials: R
authors.lastname: Su
authors.affiliation: Luminous! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore. hvdemir@ntu.edu.sg.
authors.forename: Shendre
authors.initials: S
authors.lastname: Sushant
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore. qihua@ntu.edu.sg.
authors.forename: Jun
authors.initials: J
authors.lastname: Xing
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore. qihua@ntu.edu.sg.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Luminous! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore. hvdemir@ntu.edu.sg.
authors.forename: Swee Tiam
authors.initials: ST
authors.lastname: Tan
authors.affiliation: Luminous! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore. hvdemir@ntu.edu.sg.
authors.forename: Hilmi Volkan
authors.initials: HV
authors.lastname: Demir
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore. qihua@ntu.edu.sg.
authors.forename: Qihua
authors.initials: Q
authors.lastname: Xiong