Chen Guixiong, Weng Yalian, Lai Xiaocong, Wang Wenwen, Zhou Xiongtu, Yan Qun, Guo Tailiang, Zhang Yongai, Wu Chaoxing
Opt Express. 2021 Aug 2;29(16):25812-25823. doi: 10.1364/OE.427258.
Extracting light from organic light-emitting diodes (OLEDs) and improving the angular distribution are essential for their commercial applications in illumination and displays. In this work, hybrid microlens arrays (MLAs) and gratings with periods and depths in the scale of submicron have been designed and incorporated on the lighting surface of OLEDs for simultaneous enhancement of light outcoupling efficiency and angular distribution improvement. It is found that the augmentation of light extraction efficiency is mainly attributed to the MLAs, while the gratings can improve the viewing angle by increasing the angular distribution uniformity. A novel approach was proposed by combining photoresist thermal reflow, soft-lithography and plasma treatments on polydimethylsiloxane (PDMS) surfaces synergistically to realize gratings on the wavy surface of MLAs. It has been proved that with the hybrid MLAs/gratings, the external quantum efficiency (EQE) of the OLED can reach up to 22.8%, which increased by 24% compared to that of bare OLED. Moreover, the OLED with the hybrid MLAs/gratings showed an obvious lateral enhancement at wider viewing angle.
从有机发光二极管（OLED）中提取光并改善其角分布对于其在照明和显示领域的商业应用至关重要。在这项工作中，设计了周期和深度处于亚微米尺度的混合微透镜阵列（MLA）和光栅，并将其集成在OLED的发光表面上，以同时提高光出射耦合效率和改善角分布。研究发现，光提取效率的提高主要归因于MLA，而光栅可以通过提高角分布均匀性来改善视角。提出了一种通过协同结合光刻胶热回流、软光刻和聚二甲基硅氧烷（PDMS）表面的等离子体处理来在MLA的波浪形表面上实现光栅的新方法。已经证明，采用混合MLA/光栅时，OLED的外量子效率（EQE）可高达22.8%，与裸OLED相比提高了24%。此外，具有混合MLA/光栅的OLED在更宽的视角下显示出明显的横向增强。
