Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Hong Kong SAR, China.
Opt Lett. 2013 Jul 15;38(14):2373-5. doi: 10.1364/OL.38.002373.
In this work, organic electroluminescent (EL) devices with double light-emitting layers (EMLs) having stepwise energy levels were designed to improve the EL performance of a red-light-emitting platinum(II) Schiff base complex. A series of devices with single or double EML(s) were fabricated and characterized. Compared with single-EML devices, double-EML devices showed improved EL efficiency and brightness, attributed to better balance in carriers. In addition, the stepwise distribution in energy levels of host materials is instrumental in broadening the recombination zone, thus delaying the roll-off of EL efficiency. The highest EL current efficiency and power efficiency of 17.36 cd/A and 14.73 lm/W, respectively, were achieved with the optimized double-EML devices. At high brightness of 1000 cd/m², EL efficiency as high as 8.89 cd/A was retained.
在这项工作中，设计了具有逐步能级的双发光层（EML）的有机电致发光（EL）器件，以提高红光发射铂（II）希夫碱配合物的 EL 性能。制备并表征了具有单个或双 EML（s）的一系列器件。与单 EML 器件相比，双 EML 器件显示出改进的 EL 效率和亮度，这归因于载流子更好的平衡。此外，主体材料能级的逐步分布有助于拓宽复合区，从而延迟 EL 效率的下降。通过优化的双 EML 器件实现了最高的 EL 电流效率和功率效率，分别为 17.36 cd/A 和 14.73 lm/W。在 1000 cd/m²的高亮度下，仍保持高达 8.89 cd/A 的 EL 效率。
