Multifunctional silver nanoparticle interlayer-modified ZnO as the electron-injection layer for efficient inverted organic light-emitting diodes

Lei Zhou, Heng-Yang Xiang, Yu-Fu Zhu, Qing-Dong Ou, Qian-Kun Wang, Juan Du, Rui Hu, Xian Bo Huang, Jian-Xin Tang

Research output: Contribution to journalArticleResearchpeer-review

10 Citations (Scopus)

Abstract

The insufficient electron injection constitutes the major obstacle to achieving high-performance inverted organic light-emitting diodes (OLEDs). Here, a facile electron-injection architecture featuring a silver nanoparticle (AgNPs) interlayer-modified sol-gel-derived transparent zinc oxide (ZnO) ultrathin film is proposed and demonstrated. The optimized external quantum efficiencies of the developed inverted fluorescent and phosphorescent OLEDs capitalized on our proposed electron-injection structure reached 4.0 and 21.2% at a current density of 20 mA cm-2 and increased by a factor of 1.90 and 2.86 relative to a reference device without the AgNP interlayer, while simultaneously reducing the operational voltage and substantially ameliorating the device efficiency. Detailed analyses reveal that the local surface plasmon resonance emanated from AgNPs plays three meaningful roles simultaneously: suppressing the surface plasmon polariton mode loss, aiding in energy-level alignments, and inducing and reinforcing the local exciton-plasmon coupling electric field. Among these interesting and multifunctional roles, the enhanced local exciton-plasmon coupling electric field dominates the electron injection enhancement and substantial increases the device efficiency. Additionally, the light-scattering effect also helps in recovering the trapped light energy flux and thus improves the device efficiency. The proposed approach and findings provide an alternative path to fabricate high-performance inverted OLEDs and other related organic electronic or optoelectronic devices.

Original languageEnglish
Pages (from-to)9251-9258
Number of pages8
JournalACS Applied Materials & Interfaces
Volume11
Issue number9
DOIs
Publication statusPublished - 6 Mar 2019
Externally publishedYes

Keywords

  • electron injection
  • inverted organic light-emitting diodes
  • silver nanoparticles
  • surface plasmon polariton
  • ZnO

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