Enhancing the optical performance of organic light-emitting diodes using nanoscale random rubbed structure

Cheol Shin, Seungwon Lee, Kwang Wook Choi, Young Hyun Hwang, Young Wook Park, Byeong Kwon Ju

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

In this study, we evaluated a nanoscale random rubbed structure (nRRS) used as a scattering layer in organic light-emitting diodes (OLEDs) through an innovative manufacturing method. The rubbing technique, which is conventionally utilized only for liquid crystal alignment, is a manufacturing process with excellent merit in that it can form nanoscale random corrugation in a large area without vacuum equipment even at room temperature, and it is simple and inexpensive. The optimized nRRS, fabricated via rubbing, exhibited a high transmittance of 97.8% and haze of 17.8%, making it suitable as a scattering layer for OLEDs. Owing to its random nature, the scattering effect occurred effectively by rearranging the waveguided light inside the glass substrate. The OLED combined with the optimized nRRS showed a 25.4% improvement in the external quantum efficiency. Additionally, the spectral distortion according to the viewing angle was alleviated, which was confirmed by the negligible difference in the International Commission on Illumination 1931 color space coordinates (∆(x, y) = (0.01, 0.013)). The optical performance of the nRRS–OLED was predicted through a finite-difference time-domain simulation and verified by showing results consistent with those of the fabricated device. This research is expected to be widely applied in many optical devices because it is possible to form a random corrugation on the outside of the device without the difficulty of simply fabricating a beneficial optical structure.

Original languageEnglish
JournalNanomaterials and Nanotechnology
Volume12
DOIs
Publication statusPublished - 2022 Jan 1

Bibliographical note

Funding Information:
This work was supported by Samsung Display Co, Ltd, the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (No. NRF-2020R1C1C1013567), and the Brain Korea 21 Project in 2021.

Publisher Copyright:
© The Author(s) 2022.

Keywords

  • finite-difference time-domain simulation
  • light extraction
  • Organic light-emitting diodes
  • random nanopattern
  • rubbing
  • scattering layer

ASJC Scopus subject areas

  • Biotechnology
  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Electrical and Electronic Engineering

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