Highly Efficient Light-Emitting Diodes of Colloidal Metal-Halide Perovskite Nanocrystals beyond Quantum Size

Young Hoon Kim, Christoph Wolf, Young Tae Kim, Himchan Cho, Woosung Kwon, Sungan Do, Aditya Sadhanala, Chan Gyung Park, Shi Woo Rhee, Sang Hyuk Im, Richard H. Friend, Tae Woo Lee

Research output: Contribution to journalArticle

146 Citations (Scopus)

Abstract

Colloidal metal-halide perovskite quantum dots (QDs) with a dimension less than the exciton Bohr diameter DB (quantum size regime) emerged as promising light emitters due to their spectrally narrow light, facile color tuning, and high photoluminescence quantum efficiency (PLQE). However, their size-sensitive emission wavelength and color purity and low electroluminescence efficiency are still challenging aspects. Here, we demonstrate highly efficient light-emitting diodes (LEDs) based on the colloidal perovskite nanocrystals (NCs) in a dimension > DB (regime beyond quantum size) by using a multifunctional buffer hole injection layer (Buf-HIL). The perovskite NCs with a dimension greater than DB show a size-irrespective high color purity and PLQE by managing the recombination of excitons occurring at surface traps and inside the NCs. The Buf-HIL composed of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) and perfluorinated ionomer induces uniform perovskite particle films with complete film coverage and prevents exciton quenching at the PEDOT:PSS/perovskite particle film interface. With these strategies, we achieved a very high PLQE (∼60.5%) in compact perovskite particle films without any complex post-treatments and multilayers and a high current efficiency of 15.5 cd/A in the LEDs of colloidal perovskite NCs, even in a simplified structure, which is the highest efficiency to date in green LEDs that use colloidal organic-inorganic metal-halide perovskite nanoparticles including perovskite QDs and NCs. These results can help to guide development of various light-emitting optoelectronic applications based on perovskite NCs.

Original languageEnglish
Pages (from-to)6586-6593
Number of pages8
JournalACS Nano
Volume11
Issue number7
DOIs
Publication statusPublished - 2017 Jul 25

Keywords

  • electroluminescence
  • hole injection layer
  • light-emitting diodes
  • perovskite nanocrystal
  • quantum size

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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  • Cite this

    Kim, Y. H., Wolf, C., Kim, Y. T., Cho, H., Kwon, W., Do, S., Sadhanala, A., Park, C. G., Rhee, S. W., Im, S. H., Friend, R. H., & Lee, T. W. (2017). Highly Efficient Light-Emitting Diodes of Colloidal Metal-Halide Perovskite Nanocrystals beyond Quantum Size. ACS Nano, 11(7), 6586-6593. https://doi.org/10.1021/acsnano.6b07617