Institut für Angewandte Photophysik, TU Dresden, George-Bähr-Strasse 1, D-01069 Dresden, Germany.
Nano Lett. 2012 Jan 11;12(1):424-8. doi: 10.1021/nl203743p. Epub 2011 Dec 9.
White top-emitting organic light-emitting diodes (OLEDs) attract much attention, as they are optically independent from the substrate used. While monochrome top-emitting OLEDs can be designed easily to have high-emission efficiency, white light emission faces obstacles. The commonly used thin metal layers as top electrodes turn the device into a microresonator having detrimental narrow and angular dependent emission characteristics. Here we report on a novel concept to improve the color quality and efficiency of white top-emitting OLEDs. We laminate a refractive index-matched microlens film on the top-emitting device. The microlens film acts both as outcoupling-enhancing film and an integrating element, mixing the optical modes to a broadband spectrum.
白色顶发射有机发光二极管（OLED）引起了广泛关注，因为它们的光学性质与所使用的衬底无关。虽然单色顶发射 OLED 可以很容易地设计成具有高发射效率，但白光发射却面临障碍。常用的薄金属层作为顶电极使器件成为一个微谐振器，具有有害的窄角发射特性。在这里，我们报告了一个改进白光顶发射 OLED 颜色质量和效率的新概念。我们在顶发射器件上层压一个折射率匹配的微透镜膜。微透镜膜既作为出射增强膜，也作为一个集成元件，将光学模式混合成宽带光谱。
