Deep Blue Phosphorescent OLEDs: Can Organics Live Long Enough at High Energies to be Useful?
ORAL · Invited
Abstract
Perhaps the single most important problem confronting the development of OLED displays and lighting today is how to achieve sufficiently long triplet-controlled emission device lifetime to prevent rapid color change during operation, while achieving 100% internal emission efficiency. It has been shown1 that bimolecular (e.g. triplet-polaron, triplet-triplet) annihilation provides a source of energy sufficient to destroy the blue triplet chromophore (whether a phosphor or a TADF molecule) or its host. Many materials, structures and strategies to extend blue emission lifetime based on this understanding have been demonstrated. Unfortunately, a fully satisfactory solution has not been shown where blue triplet emitter lifetime is sufficient to meet the standards of high performance displays, although white OLED illumination sources now have adequate lifetime to meet industry standards. In this talk I will discuss progress in extending blue phosphorescent OLED (PHOLED), phosphor sensitized fluorescence, and TADF lifetimes using a combination of plasmons and polaritons.2,3 In particular, I will focus on the relationship between radiative state lifetime, exciton density, and the longevity of PHOLEDs. I will discuss routes resulting in increasing the deep blue phosphorescent longevity by at least 100X via emitter design, polaritons, and optical cavity engineering, leading to blue lifetimes as long as green PHOLEDs. Lessons learned can be applied to all organic electronics that operate at high energies and energy densities.
1. “Intrinsic luminance loss in phosphorescent small-molecule organic light emitting devices due to bimolecular annihilation reactions”. N.C. Giebink, B.W. D’Andrade, M.S. Weaver, P.B. Mackenzie, J.J. Brown, M.E. Thompson, and S.R. Forrest, J. Appl. Phys., 2008. 103, 044509.
2. "Stable blue phosphorescent organic LEDs that use polariton-enhanced Purcell effects", H. Zhao, C. E. Arneson, D. Fan, and S. R. Forrest, Nature 2024 626, 300
3."Stable, deep blue tandem phosphorescent organic light-emitting diode enabled by the double-sided polariton-enhanced Purcell effect", H. Zhao, C. E. Arneson and S. R. Forrest, Nature Photonics 2025 19, 607
1. “Intrinsic luminance loss in phosphorescent small-molecule organic light emitting devices due to bimolecular annihilation reactions”. N.C. Giebink, B.W. D’Andrade, M.S. Weaver, P.B. Mackenzie, J.J. Brown, M.E. Thompson, and S.R. Forrest, J. Appl. Phys., 2008. 103, 044509.
2. "Stable blue phosphorescent organic LEDs that use polariton-enhanced Purcell effects", H. Zhao, C. E. Arneson, D. Fan, and S. R. Forrest, Nature 2024 626, 300
3."Stable, deep blue tandem phosphorescent organic light-emitting diode enabled by the double-sided polariton-enhanced Purcell effect", H. Zhao, C. E. Arneson and S. R. Forrest, Nature Photonics 2025 19, 607
*The authors thank the US Department of Energy BENEFIT program and Universal Display Corp. for partial support of this work.
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Presenters
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Stephen R Forrest
- University of Michigan