有机发光二极管光取出技术进展

摘要

有机发光二极管(OLED)经过近30年的发展,在材料开发和器件结构设计上取得了丰富成果,OLED在显示,尤其高端智能手机上已经开始大规模商用.但在照明领域,由于器件效率、寿命以及成本的原因,产业还不够成熟.器件的光波导效应和表面等离子体基元效应使绝大部分光子产生非辐射耦合,并以热能的形式消耗掉,造成了内外量子效率巨大差距;是器件效率与寿命不佳的主要原因之一.因此在OLED照明器件中,通过光取出技术将这部分光耦合出来显得十分必要.本文首先介绍了有机发光二极管的光学分析方法,从射线光学模型分析OLED器件中光能辐射的四种模式以及光能损耗机理,然后结合近几年各科研机构研究成果和产业上一些代表性专利,从内光取出和外光取出两方面总结了相关光取出技术的研究进展.最后我们对光取出技术路线进行总结.%Organic light-emitting diodes (OLEDs) have been developing rapidly in terms of materials and design over the past 30 years.They have been applied on large scales in displays,especially in high-end smartphones.However,in the field of lighting,the industry is not sufficiently mature because of the low efficiency,short life,and high cost of OLEDs.The main reason for this is that the optical waveguide effect and surface plasmon losses lead to the consumption of most of the optical energy coupled to the non-radiative thermal energy,resulting in a huge gap between the internal and external quantum efficiency.It is also one of the main causes for the poor efficiency and longevity.Therefore,it is necessary to recover the part of the light trapped inside OLED lighting devices via light extraction technology.In this paper,we introduce optical analytic methods for OLEDs by analyzing the four modes of light coupling channels and the mechanisms of light energy loss based on the ray-optical model.Then,based on the research achievements of some scientific institutions and recent representative patents in the industry,we summarize the relevant light extraction technology considering two aspects:external light extraction and internal light extraction.Finally,we discuss the development route and prospects of the light extraction technology.