材料期刊网

有机发光器件已经在全彩显示屏、可穿戴设备以及环境友好的室内照明领域获得了越来越多的关注。近年来,材料设计、器件结构以及制备工艺的革新,推动OLED器件性能在大面积、高效率、长寿命和高显色指数方面取得了一系列突破性进展。光学耦合效率是影响OLED器件中光电转换过程的关键因素之一,如何调控光学耦合、避免器件内部的光子流失、提高出光效率,对于发展高效率、高稳定的OLED技术具有重要意义。本文将围绕光学调控技术在波长依赖性、出光角度敏感性以及制备工艺兼容性方面,系统分析OLED器件中光学损耗机制,综述近年来国内外在OLED微纳结构光学调控的研究进展,并介绍最新发展的软纳米压印仿生微纳结构光学耦合调控方法。此光调控技术实现了绿光OLED器件效率达到366 cd·A-1、白光OLED效率达到123.4 lm·W-1、柔性白光OLED效率达到106 lm·W-1,为新型OLED的光学调控提供了新思路。

Organic light-emitting diodes ( OLEDs ) have gained increasing attention in applications of full-color display panels, wearable intelligent electronics and eco-friendly interior lighting. Recently, the innovations of material design, device structure and manufacturing technology have driven the performance of OLED device to reach a new stage in terms of large area, long lifetime, high efficiency and color rendering index. Light out-coupling plays a critical role on the efficiency of electron-photon conversion process, so it is of great importance in developing efficient and stable OLEDs to manipulate light out-coupling and avoid intrinsic loss of photon. In this review, we emphasize the strategies of light manipulation from the perspectives of wavelength dependency, angle sensitivity and compatibility with fabrication process. Various optical loss channels are analyzed, and recent developments of micro/nanostructure-stimulated light out-coupling for OLEDs are overviewed. At last, we introduce our newly developed technique of light manipulation with biomimetic moth-eye nanostructure via soft nanoimprint lithography. This technique obtains extremely high power efficiencies of 123. 4 lm·W-1 and 106 lm·W-1 for glass and plastic based white OLEDs respectively, as well as current efficiency of 366 cd·A-1 for green OLED. This technique is expected to accelerate the commercialization of large-scale and low-cost OLED panels, and to inspire new design of advanced device architecture.