Abstract
Blue phosphorescent organic light-emitting diodes (PhOLEDs) can deliver superior electroluminescence efficiencies than blue fluorescent OLEDs; however, their commercial debut has been delayed by short device lifetimes, especially for deep-blue PhOLEDs with Commission International de l’Eclairage y co-ordinates of less than 0.20. Here we report the use of new dopant and host materials to create a blue PhOLED device with a y co-ordinate of 0.197 and a long device lifetime of LT70 = 1,113 h [Initial luminance (L0) = 1,000 cd m–2]. Introducing bulky 3,5-di-tert-butyl-phenyl into the N-heterocyclic carbene moiety in the Pt(II) complex enhanced the photochemical stability of the high-lying metal-centred triplet state and prevented undesirable host–guest interactions, contributing to a longer device lifetime and higher colour purity. For the exciplex-forming host, the hole-transporting and electron-transporting host materials utilized a triphenylsilyl group for enhanced stability, which also improved the device lifetime.
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Data availability
The data that support the findings of this study are available from the corresponding authors on reasonable request. All data generated or analysed during this study are included in this published article and its Supplementary Information.
References
Baldo, M., Thompson, M. E. & Forrest, S. High-efficiency fluorescent organic light-emitting devices using a phosphorescent sensitizer. Nature 403, 750–753 (2000).
Segal, M. et al. Extrafluorescent electroluminescence in organic light-emitting devices. Nat. Mater. 6, 374 (2007).
Uoyama, H., Goushi, K., Shizu, K., Nomura, H. & Adachi, C. Highly efficient organic light-emitting diodes from delayed fluorescence. Nature 492, 234–238 (2012).
Nakanotani, H., Masui, K., Nishide, J., Shibata, T. & Adachi, C. Promising operational stability of high-efficiency organic light-emitting diodes based on thermally activated delayed fluorescence. Sci. Rep. 3, 1–6 (2013).
Wong, M. & Zysman-Colman, E. Purely organic thermally activated delayed fluorescence materials for organic light-emitting diodes. Adv. Mater. 29, 1605444 (2017).
Sun, J. W. et al. A fluorescent organic light‐emitting diode with 30% external quantum efficiency. Adv. Mater. 26, 5684–5688 (2014).
Hatakeyama, T. et al. Ultrapure blue thermally activated delayed fluorescence molecules: efficient HOMO–LUMO separation by the multiple resonance effect. Adv. Mater. 28, 2777 (2016).
Byeon, S. Y., Lee, D. R., Yook, K. S. & Lee, J. Y. Recent progress of singlet‐exciton‐harvesting fluorescent organic light‐emitting diodes by energy transfer processes. Adv. Mater. 31, 1803714 (2019).
Klimes, K., Zhu, Z. Q. & Li, J. Efficient blue phosphorescent OLEDs with improved stability and color purity through judicious triplet exciton management. Adv. Funct. Mater. 29, 1903068 (2019).
Holmes, R., Forrest, S., Tung, Y.-J., Kwong, R. & Brown, J. Blue organic electrophosphorescence using exothermic host–guest energy transfer. Appl. Phys. Lett. 82, 2422 (2003).
Tang, M. et al. Dendritic luminescent gold(III) complexes for highly efficient solution-processable organic light-emitting devices. Angew. Chem. 125, 464–467 (2013).
Hopkinson, M. N., Richter, C., Schedler, M. & Glorius, F. An overview of N-heterocyclic carbenes. Nature 510, 485–496 (2014).
Chang, C. F. et al. Highly efficient blue‐emitting iridium(III) carbene complexes and phosphorescent OLEDs. Angew. Chem. Int. Ed. 47, 4542–4545 (2008).
Lee, J. et al. Deep blue phosphorescent organic light-emitting diodes with very high brightness and efficiency. Nat. Mater. 15, 92–98 (2016).
Cao, L. et al. Efficient and stable organic light-emitting devices employing phosphorescent molecular aggregates. Nat. Photon. 15, 230–237 (2021).
Hang, X.-C., Fleetham, T., Turner, E., Brooks, J. & Li, J. Highly efficient blue-emitting cyclometalated platinum(II) complexes by judicious molecular design. Angew. Chem. Int. Ed. 52, 6753–6756 (2013).
Li, G., Fleetham, T., Turner, E., Hang, X.-C. & Li, J. Highly efficient and stable narrow-band phosphorescent emitters for OLED applications. Adv. Opt. Mater. 3, 390–397 (2014).
Zhang, Y., Lee, J. & Forrest, S. R. Tenfold increase in the lifetime of blue phosphorescent organic light-emitting diodes. Nat. Commun. 5, 1–7 (2014).
Cho, H. et al. Phenylimidazole-based homoleptic iridium (III) compounds for blue phosphorescent organic light-emitting diodes with high efficiency and long lifetime. Org. Electron. 34, 91–96 (2016).
Fleetham, T. B., Huang, L., Klimes, K., Brooks, J. & Li, J. Tetradentate Pt(II) complexes with 6-membered chelate rings: a new route for stable and efficient blue organic light emitting diodes. Chem. Mater. 28, 3276–3282 (2016).
Song, W. & Lee, J. Degradation mechanism and lifetime improvement strategy for blue phosphorescent organic light-emitting diodes. Adv. Optical Mater. 5, 1600901 (2017).
Kim, S. et al. Degradation of blue-phosphorescent organic light-emitting devices involves exciton-induced generation of polaron pair within emitting layers. Nat. Commun. 9, 1211 (2018).
Maheshwaran, A. et al. High efficiency deep-blue phosphorescent organic light-emitting diodes with CIE x, y (≤ 0.15) and low efficiency roll-off by employing a high triplet energy bipolar host material. Adv. Funct. Mater. 28, 1802945 (2018).
Jung, M., Lee, K. H., Lee, J. Y. & Kim, T. A bipolar host based high triplet energy electroplex for an over 10,000 h lifetime in pure blue phosphorescent organic light-emitting diodes. Mater. Horiz. 7, 559–565 (2020).
Huh, J. S., Sung, M. J., Kwon, S. K., Kim, Y. H. & Kim, J. J. Highly efficient deep blue phosphorescent OLEDs based on tetradentate Pt(II) complexes containing adamantyl spacer groups. Adv. Funct. Mater. 31, 2100967 (2021).
Su, S.-J., Cai, C., Takamatsu, J. & Kido, J. A host material with a small singlet–triplet exchange energy for phosphorescent organic light-emitting diodes: guest, host, and exciplex emission. Org. Electron. 13, 1937–1947 (2012).
Wang, X. et al. Highly efficient deep‐blue electrophosphorescent Pt(II) compounds with non‐distorted flat geometry: tetradentate versus macrocyclic chelate Ligands. Adv. Funct. Mater. 27, 1604318 (2017).
Ko, S.–B. et al. Organic light-emitting device and electronic apparatus including the same. European Patent 03544076 (2020).
Park, Y. S. et al. Exciplex-forming co-host for organic light-emitting diodes with ultimate efficiency. Adv. Funct. Mater. 23, 4914–4920 (2013).
Jankus, V., Chiang, C.-J., Dias, F. & Monkman, A. Deep blue exciplex organic light-emitting diodes with enhanced efficiency; P-type or E-type triplet conversion to singlet excitons? Adv. Mater. 25, 1455–1459 (2013).
Choi, S. et al. Optimized structure of silane-core containing host materials for highly efficient blue TADF OLEDs. J. Mater. Chem. C 5, 6570–6577 (2017).
Choi, K. H., Lee, K. H., Lee, J. Y. & Kim, T. Simultaneous achievement of high efficiency and long lifetime in deep blue phosphorescent organic light‐emitting diodes. Adv. Opt. Mater. 7, 1901374 (2019).
Costa Rubén, D. et al. Efficient and long-living light-emitting electrochemical cells. Adv. Funct. Mater. 20, 1511–1520 (2010).
Kang, S., Kim, T. & Lee, J. Y. New design strategy for chemically-stable blue phosphorescent materials: improving the energy gap between T1 and 3MC states. Phys. Chem. Chem. Phys. 23, 3543–3551 (2021).
Wang, Y., Peng, Q. & Shuai, Z. A computational scheme for evaluating the phosphorescence quantum efficiency: applied to blue-emitting tetradentate Pt(II) complexes. Mater. Horiz. 9, 334–341 (2022).
Li, G. et al. N-Heterocyclic carbene-tetradetate Pd(II) complexes for deep-blue phosphorescent materials. Organometallics 40, 472–481 (2021).
Wang, Y., Yun, J. H., Wang, L. & Lee, J. Y. High triplet energy hosts for blue organic light-emitting diodes. Adv. Funct. Mater. 31, 2008332 (2021).
Mollere, P. & Hoffmann, R. Augmented silicon–carbon bond strengths via d–σ hyperconjugation. J. Am. Chem. Soc. 97, 3680–3682 (1975).
Kim, S. Y. et al. Organic light-emitting diodes with 30% external quantum efficiency based on a horizontally oriented emitter. Adv. Funct. Mater. 23, 3896–3900 (2013).
Lee, S., Kim, K. H., Limbach, D., Park, Y. S. & Kim, J. J. Low roll-off and high efficiency orange organic light emitting diodes with controlled co-doping of green and red phosphorescent dopants in an exciplex forming co-host. Adv. Funct. Mater. 23, 4105–4110 (2013).
Lee, S. et al. High efficiency and non-color-changing orange organic light emitting diodes with red and green emitting layers. Org. Electron. 14, 1856–1860 (2013).
Sasabe, H. & Kido, J. Multifunctional materials in high-performance OLEDs: challenges for solid-state lighting. Chem. Mater. 23, 621–630 (2011).
Seino, Y., Sasabe, H., Pu, Y. J. & Kido, J. High-performance blue phosphorescent OLEDs using energy transfer from exciplex. Adv. Mater. 26, 1612–1616 (2014).
Lee, J. H. et al. An exciplex forming host for highly efficient blue organic light emitting diodes with low driving voltage. Adv. Funct. Mater. 25, 361–366 (2015).
Dennington, R., Keith, T. & Millam, J. GaussView Version 5.0 (Semichem, 2016).
Acknowledgements
Y.Y. (Ewha Womans’ Univ.) acknowledges the Midcareer Research Program (NRF-2019R1A2C2003969), the Basic Research Laboratory Program (NRF-2019R1A4A1029052) and the Nano Material Technology Development Program (NRF-2021M3D1A2049323) through the National Research Foundation grants funded by the Ministry of Science, Information and Communication Technology, and Future Planning of Korea.
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J.S., S.K., S.-B.K., H.A., D.S. and Y.Y. analysed the data and wrote the manuscript under supervision of C.C. and S.K., J.S., Y.L. and S.-B.K. designed the dopant molecule. S.-B.K. and S.K. synthesized and characterized the dopant material. H.A. designed the host molecule. H.U. and H.A. synthesized and characterized the host materials under supervision of S.-H.H. J.S. performed exciplex analysis. S.K. conducted theoretical calculations for all of the materials. J.S. and Y.L. analysed the device data. P.J. carried out device fabrication. Y.Y. coordinated the research at Ewha Womans University. D.S. performed the degradation experiments. All authors discussed the progress of research and reviewed the manuscript.
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Synthesis, Experimental, Methods for Device fabrication and measurements, Supplementary Figs. 1–26, Tables 1–9 and References.
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Sun, J., Ahn, H., Kang, S. et al. Exceptionally stable blue phosphorescent organic light-emitting diodes. Nat. Photon. 16, 212–218 (2022). https://doi.org/10.1038/s41566-022-00958-4
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DOI: https://doi.org/10.1038/s41566-022-00958-4
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