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Near-infrared organic light-emitting diodes with very high external quantum efficiency and radiance

Nature Photonics volume 11, pages 63–68 (2017)Cite this article

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Abstract

Bright and efficient organic emitters of near-infrared light would be of use in applications ranging from biological imaging and medical therapy to night-vision devices. Here we report how a new class of Pt(II) complex phosphors have enabled the fabrication of organic light-emitting diodes that emit light at 740 nm with very high efficiency and radiance due to a high photoluminescence quantum yield of ∼81% and a highly preferred horizontal dipole orientation. The best devices exhibited an external quantum efficiency of 24 ± 1% in a normal planar organic light-emitting diode structure. The incorporation of a light out-coupling hemisphere structure further boosts the external quantum efficiency up to 55 ± 3%.

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Figure 1: Chemical structure and optical properties of Pt(II) complexes 1–3.
Figure 2: GIWAXS data for thin films of Pt(II) complexes 1–3.
Figure 3: Molecular orbitals of Pt(II) complex 1.
Figure 4: Device performance of optimized NIR OLEDs.

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Acknowledgements

This research was supported by the Ministry of Science and Technology of Taiwan. We also thank the National Center for High-performance Computing (NCHC) for the computer time and facilities.

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Authors and Affiliations

  1. Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan

    Kiet Tuong Ly & Yun Chi

  2. Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan

    Ren-Wu Chen-Cheng, Hao-Wu Lin & Yu-Jeng Shiau

  3. Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan

    Shih-Hung Liu & Pi-Tai Chou

  4. Institute of Nuclear Energy Research, Taoyuan, 32546, Taiwan

    Cheng-Si Tsao & Yu-Ching Huang

  5. Department of Materials Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan

    Cheng-Si Tsao

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Contributions

K.T.L. conducted the synthesis and characterization of the Pt(II) complexes. R.-W.C.-C. executed the OLED fabrication and photophysical measurements. H.-W.L. designed the OLED structures, analysed the solid-state and OLED data and prepared the manuscript. Y.-J.S. did the optical modelling and simulations. S.-H.L. performed the computational calculations. P.-T.C. developed the theoretical approach, interpreted the photophysics and prepared the manuscript. C.-S.T. and Y.-C.H. conducted the GIWAXS measurements and analysed the data. Y.C. designed the Pt(II) complexes and prepared the manuscript. All authors discussed the results and contributed to the paper.

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Correspondence to Hao-Wu Lin, Pi-Tai Chou or Yun Chi.

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The authors declare no competing financial interests.

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Tuong Ly, K., Chen-Cheng, RW., Lin, HW. et al. Near-infrared organic light-emitting diodes with very high external quantum efficiency and radiance. Nature Photon 11, 63–68 (2017). https://doi.org/10.1038/nphoton.2016.230

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