Fujian Key Laboratory of Polymer Materials, College of Chemistry and Materials Science , Fujian Normal University , Fuzhou 350007 , China.
Fujian Institute of Research on the Structure of Matter , Chinese Academy of Sciences , Fuzhou , Fujian 350002 , China.
ACS Appl Mater Interfaces. 2018 May 9;10(18):15980-15987. doi: 10.1021/acsami.8b00048. Epub 2018 Apr 25.
Two-dimensional (2D) white-light-emitting hybrid perovskites (WHPs) are promising active materials for single-component white-light-emitting diodes (WLEDs) driven by UV. However, the reported WHPs exhibit low quantum yields (≤9%) and low color rendering index (CRI) values less than 85, which does not satisfy the demand of solid-state lighting applications. In this work, we report a series of mixed-halide 2D layered WHPs (CHCHNH)PbBr Cl (0 < x < 4) obtained from the phenethylammonium cation. Unlike the reported WHPs including (CHCHNH)PbCl, the mixed-halide perovskites display morphology-dependent white emission for the different extents of self-absorption. Additionally, the amount of Br has a huge influence on the photophysical properties of mixed-halide WHPs. With the increasing content of Br, the quantum yields of WHPs increase gradually from 0.2 to 16.9%, accompanied by tunable color temperatures ranging from 4000 K ("warm" white light) to 7000 K ("cold" white light). When applied to the WLEDs, the mixed-halide perovskite powders exhibit tunable white electroluminescent emission with very high CRI of 87-91.
二维（2D）白光发射混合卤化物钙钛矿（WHPs）是一种很有前途的用于单组分紫外光驱动的白光发光二极管（WLEDs）的活性材料。然而，已报道的 WHPs 的量子产率（≤9%）和显色指数（CRI）值较低，小于 85，这不能满足固态照明应用的需求。在这项工作中，我们报道了一系列由苯乙基铵阳离子得到的混合卤化物 2D 层状 WHPs（CHCHNH）PbBrCl（0 < x < 4）。与包括（CHCHNH）PbCl 的报道的 WHPs 不同，混合卤化物钙钛矿显示出形态依赖性的白光发射，这与自吸收的不同程度有关。此外，Br 的含量对混合卤化物 WHPs 的光物理性质有很大的影响。随着 Br 含量的增加，WHPs 的量子产率逐渐从 0.2 增加到 16.9%，同时伴随着可调的色温范围从 4000 K（“暖”白光）到 7000 K（“冷”白光）。当应用于 WLEDs 时，混合卤化物钙钛矿粉末表现出可调谐的白光电致发光发射，具有非常高的 CRI 值为 87-91。
