Highly efficient sky blue electroluminescence from ligand-activated copper iodide clusters: Overcoming the limitations of cluster light-emitting diodes
Highly efficient sky blue electroluminescence from ligand-activated copper iodide clusters: Overcoming the limitations of cluster light-emitting diodes
复制标题
配体激活碘化铜簇的高效天蓝色电致发光：克服簇发光二极管的局限性
DOI：
10.1126/sciadv.aav9857
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发表时间：
2019
期刊：
影响因子：
13.6
通讯作者：
Xu Hui
中科院分区：
文献类型：
--
作者：
Xie Mingchen;Han Chunmiao;Liang Qianqian;Zhang Jing;Xie Guohua;Xu Hui
配体激活策略使天蓝色簇发光二极管具有创纪录的7000尼特亮度和约8%的效率。使用团簇发射器的有机发光二极管最近已经成为一种灵活的光电平台，以扩展其生物和光学应用。然而，它们的低效的以团簇为中心的激发态和不足的电学性质限制了器件性能。在这里，我们在有机配体中引入供体基团以形成配体活化的簇，从而能够制造第一个基于簇的天蓝色发光器件，其亮度和外量子效率分别增加了30倍和8倍，分别高达~7000尼特和~ 8%。我们发现，电子供体基团的供电子效应可以增强配体为中心的过渡和彻底消除集群为中心的激发态通过离域的分子过渡轨道从集群单元的配体，导致13倍的光致发光量子产率增加。反过来，团簇单元的优异刚性和光稳定性提高了器件的色纯度和效率稳定性。这些结果将推动高性能的光电团簇的配体工程的进一步发展。
A ligand activation strategy enables sky-blue cluster light-emitting diode with record 7000 nits brightness and ~8% efficiency. Organic light-emitting diodes using cluster emitters have recently emerged as a flexible optoelectronic platform to extend their biological and optical applications. However, their inefficient cluster-centered excited states and deficient electrical properties limit device performance. Here, we introduce donor groups in organic ligands to form ligand-activated clusters, enabling the fabrication of the first cluster-based sky blue–emitting device with a record 30- and 8-fold increased luminance and external quantum efficiency up to ~7000 nits and ~8%, respectively. We show that the electron-donating effect of donor groups can enhance ligand-centered transitions and thoroughly eliminate cluster-centered excited states by delocalizing the molecular transition orbitals from the cluster unit to the ligand, leading to 13-fold increased photoluminescence quantum yield. In turn, the excellent rigidity and photostability of the cluster unit improve the color purity and efficiency stability of the devices. These results will motivate the further development of high-performance optoelectronic clusters by ligand engineering.