Efficiently releasing the trapped energy flow in white organic light-emitting diodes with multifunctional nanofunnel arrays

Lei Zhou, Qing-Dong Ou, Yan-Qing Li, Heng-Yang Xiang, Lu-Hai Xu, Jing-De Chen, Chi Li, Su Shen, Shuit-Tong Lee, Jian-Xin Tang

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44 Citations (Scopus)

Abstract

White organic light-emitting diodes (OLEDs) hold great promise for applications in displays and lighting due to high efficiency and superior white color balance. However, further improvement in efficiency remains a continuous and urgent demand due to limited energy flow extraction. A powerful method for drastically releasing the trapped energy flow in conventional white OLEDs is demonstrated by implementing unique quasi-periodic subwavelength nanofunnel arrays (NFAs) via soft nanoimprinting lithography, which is ideal for enhancing light extraction without any spectral distortion or angular dependence. The resulting efficiency is over 2 times that of a conventional OLED used as a comparison. The external quantum efficiency and power efficiency are raised to 32.4% and 56.9 lm W-1, respectively. Besides, the substantial increase in efficiency over a broad bandwidth with angular color stability, the experimental proofs show that the NFA-based extraction structure affords the enticing capacity against scrubbing and the self-cleaning feature, which are critical to the commercial viability in practical applications.

Original languageEnglish
Pages (from-to)2660-2668
Number of pages9
JournalAdvanced Functional Materials
Volume25
Issue number18
DOIs
Publication statusPublished - 13 May 2015
Externally publishedYes

Keywords

  • light extraction
  • nanofunnel arrays
  • self-cleaning
  • soft nanoimprinting lithography
  • white organic light-emitting diodes

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