Nanoshuttered OLEDs: Unveiled invisible auxiliary electrode

Yong Sub Shim, Ju Hyun Hwang, Hyun Jun Lee, Kyung Bok Choi, Kyu Nyun Kim, Cheol Hwee Park, Sun Gyu Jung, Young Wook Park, Byeong Kwon Ju

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

In this study, organic light-emitting diodes (OLEDs) with enhanced optical properties are fabricated by inserting a nanosized stripe auxiliary electrode layer (nSAEL) between the substrate and an indium tin oxide (ITO) layer. This design can avoid the shortcomings of conventional microsized layers while maintaining high optical uniformity due to the improved conductivity of the electrode. The primary advantage is that the nSAEL (submicrometer scale) is no longer visible to the naked eye. Moreover, the reflective shuttered (grating) structure of the nSAEL increases the forward-directed light by the microcavity (MC) effect and minimizes the loss of light by the extracting the surface plasmon polariton (SPP) mode. In this study, the degree of the MC and SPP can be controlled with the parameters of the nSAEL by simply conjugating the conditions of laser interference lithography (LIL). Therefore, the current and power efficiencies of the device with an nSAEL with optimized parameters are 1.17 and 1.23 times higher than the reference device at 1000 cd/m<sup>2</sup>, respectively, and at these parameters, the overall sheet resistance is reduced to less than half (48%). All of the processes are verified by comparing the computational simulation results and the experimental results obtained with the actual fabricated device. An invisible nanosized stripe auxiliary electrode layer (nSAEL) for OLEDs that can avoid the shortcomings of conventional microsized layers while maintaining high optical uniformity due to the improved conductivity of the electrode is proposed. An additional advantage is that the structure of the nSAEL increases light extraction by utilizing the microcavity (MC) effect and the outcoupled surface plasmon polariton (SPP) mode.

Original languageEnglish
Pages (from-to)6414-6421
Number of pages8
JournalAdvanced Functional Materials
Volume24
Issue number41
DOIs
Publication statusPublished - 2014 Nov 5

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Keywords

  • laser interference lithography
  • microcavities
  • nanosized auxiliary electrodes
  • organic light-emitting diodes
  • surface plasmon polariton

ASJC Scopus subject areas

  • Biomaterials
  • Electrochemistry
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Shim, Y. S., Hwang, J. H., Lee, H. J., Choi, K. B., Kim, K. N., Park, C. H., ... Ju, B. K. (2014). Nanoshuttered OLEDs: Unveiled invisible auxiliary electrode. Advanced Functional Materials, 24(41), 6414-6421. https://doi.org/10.1002/adfm.201401253