Color-Pure Violet-Light-Emitting Diodes Based on Layered Lead Halide Perovskite Nanoplates

详细信息    查看全文

• 作者：Dong Liang ; Yuelin Peng ; Yongping Fu ; Melinda J. Shearer ; Jingjing Zhang ; Jianyuan Zhai ; Yi Zhang ; Robert J. Hamers ; Trisha L. Andrew ; Song Jin
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：July 26, 2016
• 年：2016
• 卷：10
• 期：7
• 页码：6897-6904
• 全文大小：392K
• 年卷期：0
• ISSN：1936-086X

文摘

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.