Highly improved light extraction with a reduced spectrum distortion of organic light-emitting diodes composed by the sub-visible wavelength nano-scale periodic (∼250 nm) structure and micro-lens array

Kyung Bok Choi, Se Joong Shin, Tae Hyun Park, Hyun Jun Lee, Ju Hyun Hwang, Jung Ho Park, Bo Yeon Hwang, Young Wook Park, Byeong Kwon Ju

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18 Citations (Scopus)


Out-coupling enhanced organic light-emitting diodes (OLEDs) with micro-lens arrays and a nano-scale periodic light-extraction structure - a photonic crystal (PC) - utilizing laser interference lithography (LIL) are demonstrated. Generally, PC-based OLEDs suffer from a distorted and shifted spectrum, despite a highly improved intensity. However, in this study, we demonstrate PC-based OLEDs with a distortion-free spectrum and a highly improved out-coupling performance. It was found that spectrum distortion decreased with the pitch size of the PC. The PC-based OLED with a 250 nm pitch size showed a dramatically reduced spectral shift: International Commission on Illumination 1931 color coordinate of (Δ0.00, Δ0.00) and Δpeak wavelength of 0 nm as compared with the reference. Simultaneously, the external quantum efficiency and the power efficiency were enhanced by up to 178% and 264%, respectively, as compared with the reference. Moreover, through the LIL, simple and maskless processes were achieved for a light-extraction structure over a large area.

Original languageEnglish
Pages (from-to)111-117
Number of pages7
JournalOrganic Electronics: physics, materials, applications
Issue number1
Publication statusPublished - 2014 Jan 1



  • Laser interference lithography (LIL)
  • Micro-lens arrays
  • Nano-scale periodic pattern
  • Organic light-emitting diodes (OLEDs)
  • Out-coupling
  • Photonic crystal

ASJC Scopus subject areas

  • Biomaterials
  • Electronic, Optical and Magnetic Materials
  • Materials Chemistry
  • Electrical and Electronic Engineering
  • Chemistry(all)
  • Condensed Matter Physics

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