Ouyang Xinhua, Li Xiang-Long, Ai Ling, Mi Dongbo, Ge Ziyi, Su Shi-Jian
†Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, P. R. China.
‡State Key Laboratory of Luminescent Materials and Devices (South China University of Technology) and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China.
ACS Appl Mater Interfaces. 2015 Apr 22;7(15):7869-77. doi: 10.1021/am5081106. Epub 2015 Apr 8.
Two blue fluorophores with excellent hybridized local and charge-transfer (HLCT) and "hot exciton" properties were developed as the blue emitter and the host for orange-red phosphor to achieve highly efficient fluorescent/phosphorescent (F/P) hybrid white organic light-emitting diodes (WOLEDs) in a single-emissive-layer single-dopant (SEML-SD) architecture even at a high concentration of phosphorescent dopant. In the devices, part of the triplet excitons of the blue fluorophores can be utilized to realize reverse intersystem crossing from the triplet excited states to the singlet excited states for blue emission, and the diffusion volume range of the triplet excitons is reduced significantly. When the phosphorescent dopant concentration is up to 1.0 wt %, which is ten times higher than the traditional single-EML-SD F/P hybrid WOLEDs, highly efficient white emission was still achieved with maximum total external quantum efficiency (EQE) of 23.8%, current efficiency (CE) of 56.1 cd A(-1), and power efficiency (PE) of 62.9 lm W(1-). The results will supply a novel method for obtaining high efficiency F/P hybrid WOLEDs in a SEML-SD architecture with easily controllable doping concentration.
开发了两种具有优异的杂化局域和电荷转移（HLCT）以及“热激子”特性的蓝色荧光团，作为蓝色发光体和用于橙红色磷光体的主体，以实现单发射层单掺杂（SEML-SD）结构的高效荧光/磷光（F/P）混合白色有机发光二极管（WOLED），即使在磷光掺杂剂浓度较高的情况下也是如此。在这些器件中，蓝色荧光团的部分三重态激子可被用于实现从三重态激发态到单重态激发态的反向系间窜越以实现蓝色发光，并且三重态激子的扩散体积范围显著减小。当磷光掺杂剂浓度高达1.0 wt%时，这比传统的单发射层单掺杂F/P混合WOLED高十倍，仍实现了高效白色发光，最大总外量子效率（EQE）为23.8%，电流效率（CE）为56.1 cd A⁻¹，功率效率（PE）为62.9 lm W⁻¹。这些结果将为在具有易于控制掺杂浓度的SEML-SD结构中获得高效F/P混合WOLED提供一种新方法。
