High Performance Exciplex-Based Fluorescence鈥揚hosphorescence White Organic Light-Emitting Device with Highly Simplified Structure

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• 作者：Zhan Chen ; Xiao-Ke Liu ; Cai-Jun Zheng ; Jun Ye ; Chuan-Lin Liu ; Fan Li ; Xue-Mei Ou ; Chun-Sing Lee ; Xiao-Hong Zhang
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：August 11, 2015
• 年：2015
• 卷：27
• 期：15
• 页码：5206-5211
• 全文大小：325K
• ISSN：1520-5002

文摘

Exciplex systems have become increasingly important due to their good performance in devices. Considering their bipolar transporting properties, exciplex systems with strong blue fluorescence and high triplet energies could potentially be ideal hosts for fluorescence鈥損hosphorescence hybrid (F鈥揚) white organic light-emitting diodes (WOLEDs). Here we achieved an efficient blue exciplex system formed with a new material (4-dimesitylboryl)phenyltriphenylamine (TPAPB) and 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi), which exhibited a high photoluminescence quantum yield of 44.1%. Using only these two organic materials, a high performance blue-emitting OLED was fabricated with a maximum external quantum efficiency (EQE) of 7.0 卤 0.4%. Such high efficiency is not only among the highest results of blue fluorescent organic light-emitting diodes (OLEDs) but also indicates that high 蠂 (fraction of excitons that can potentially radiatively decay) can be as well achieved via a TTA triplet up-conversion process. By simply doping an orange phosphor, the first F鈥揚 WOLED using an exciplex host system was realized with a single-emission-layer structure and merely three organic materials. The WOLED exhibits a maximum power efficiency, current efficiency, and EQE of 29.6 卤 0.2 lm W^鈥?, 42.5 卤 0.3 cd A^鈥?, and 15.7 卤 0.3%, respectively. To the best of our knowledge, this highly efficient and structurally simplified exciplex-based F鈥揚 WOLED is truly unprecedented.