title: Color-Pure Violet-Light-Emitting Diodes Based on Layered Lead Halide Perovskite Nanoplates.
abstract: Violet electroluminescence is rare in both inorganic and organic light-emitting diodes (LEDs). Low-cost and room-temperature solution-processed lead halide perovskites with high-efficiency and color-tunable photoluminescence are promising for LEDs. Here, we report room-temperature color-pure violet LEDs based on a two-dimensional lead halide perovskite material, namely, 2-phenylethylammonium (C6H5CH2CH2NH3(+), PEA) lead bromide [(PEA)2PbBr4]. The natural quantum confinement of two-dimensional layered perovskite (PEA)2PbBr4 allows for photoluminescence of shorter wavelength (410 nm) than its three-dimensional counterpart. By converting as-deposited polycrystalline thin films to micrometer-sized (PEA)2PbBr4 nanoplates using solvent vapor annealing, we successfully integrated this layered perovskite material into LEDs and achieved efficient room-temperature violet electroluminescence at 410 nm with a narrow bandwidth. This conversion to nanoplates significantly enhanced the crystallinity and photophysical properties of the (PEA)2PbBr4 samples and the external quantum efficiency of the violet LED. The solvent vapor annealing method reported herein can be generally applied to other perovskite materials to increase their grain size and, ultimately, improve the performance of optoelectronic devices based on perovskite materials.
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Dong
authors.initials: D
authors.lastname: Liang
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Yuelin
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Yongping
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Melinda J
authors.initials: MJ
authors.lastname: Shearer
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Jianyuan
authors.initials: J
authors.lastname: Zhai
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hamers
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Trisha L
authors.initials: TL
authors.lastname: Andrew
authors.affiliation: Department of Chemistry and ‡Department of Electrical and Computer Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Song
authors.initials: S
authors.lastname: Jin
keywords: layered perovskite; nanoplate; solvent vapor annealing; violet-light-emitting diode (LED)