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Stable pure-blue hyperfluorescence organic light-emitting diodes with high-efficiency and narrow emission

An Author Correction to this article was published on 12 January 2021

This article has been updated

Abstract

Organic light-emitting diodes (OLEDs) are a promising light-source technology for future generations of display1,2. Despite great progress3,4,5,6,7,8,9,10,11,12, it is still challenging to produce blue OLEDs with sufficient colour purity, lifetime and efficiency for applications. Here, we report pure-blue (Commission Internationale de l’ Eclairage (CIE) coordinates of 0.13, 0.16) OLEDs with high efficiency (external quantum efficiency of 32 per cent at 1,000 cd m−2), narrow emission (full-width at half-maximum of 19 nm) and good stability (95% of the initial luminacnce (LT95) of 18 hours at an initial luminance of 1,000 cd m−2). The design is based on a two-unit stacked tandem hyperfluorescence OLED with improved singlet-excited-state energy transfer from a sky-blue assistant dopant exhibiting thermally activated delayed fluorescence (TADF) called hetero-donor-type TADF(HDT-1) to a pure-blue emitter. With stricter control of device fabrication and procedures it is expected that device lifetimes will further improve to rival commercial fluorescent blue OLEDs.

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Fig. 1: Photo-physical characteristics.
Fig. 2: Pure-blue OLED performances.
Fig. 3: Luminance change versus operational time (at an initial luminance of 1,000 cd m−2).

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

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Acknowledgements

We acknowledge JNC Petrochemical Corporation for synthesizing ν-DABNA. We thank N. Nakamura and K. Kusuhara for technical assistance with this research, and H. Fujimoto, H.-W. Mo and K. Nagayoshi for help in fabricating OLEDs. We also thank Y. Tsuchiya, U. Balijapalli, Y. S. Yang, A. Endo and D. P.-K. Tsang for discussions. This work was supported financially by the Program for Building Regional Innovation Ecosystems of the Ministry of Education, Culture, Sports, Science and Technology, Japan.

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C.A. supervised the project. C.-Y.C. designed, synthesized and characterized the sky-blue TADF emitters. M.T. fabricated the OLEDs and characterized the device performances. C.-Y.C., M.T., H.N. and C.A. contributed to the manuscript writing. M.T., Y.-T.L., Y.-W.W., H.N., T.H. and C.A. contributed to discussions. All authors discussed the progress of the research and reviewed the manuscript.

Corresponding authors

Correspondence to Chin-Yiu Chan or Chihaya Adachi.

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C.A. is the external advisor of one of the sponsors of this work (Kyulux). The other authors declare no competing financial interests. Kyushu University and Kyulux have filed patent applications on materials and devices.

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Supplementary Figures 1–24, Supplementary Tables 1–3

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Chan, CY., Tanaka, M., Lee, YT. et al. Stable pure-blue hyperfluorescence organic light-emitting diodes with high-efficiency and narrow emission. Nat. Photonics 15, 203–207 (2021). https://doi.org/10.1038/s41566-020-00745-z

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