Acta Phys. -Chim. Sin. ›› 2017, Vol. 33 ›› Issue (8): 1548-1572.doi: 10.3866/PKU.WHXB201704283

• REVIEW • Previous Articles     Next Articles

Progress of Light Extraction Technology for Organic Light-Emitting Diodes

Lu-Hua LAN1,Hong TAO1,2,Mei-Ling LI1,Dong-Yu GAO2,Jian-Hua ZOU1,2,*(),Miao XU1,Lei WANG1,*(),Jun-Biao PENG1   

  1. 1 State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China
    2 New Vision Opto-Electronic Technology Co., Ltd., Guangzhou 510530, P. R. China
  • Received:2017-01-18 Published:2017-06-14
  • Contact: Jian-Hua ZOU,Lei WANG E-mail:zou1007@gmail.com;mslwang@scut.edu.cn
  • Supported by:
    The project was supported by the National Key Basic Research and Development Program of China(2016YFB0401005);The project was supported by the National Key Basic Research and Development Program of China(2016YFF0203603);National Natural Science Foundation of China(61401156);Special Support Program of Guangdong, China(2014TQ01C321);China Post-Doctoral Science Foundation(2015M582380);China Post-Doctoral Science Foundation(2016M590779);and Pear River S & T Nova Program of Guangzhou, China(201506010015);and Pear River S & T Nova Program of Guangzhou, China(201505051412482);and Pear River S & T Nova Program of Guangzhou, China(201710010066)

Abstract:

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.

Key words: Organic light-emitting diode, Luminous efficiency, Out-coupling efficiency, Internal light extraction, External light extraction

MSC2000: 

  • O644