Unraveling the Fate of Host Excitons in Host–Guest Phosphorescent Organic Light-Emitting Diodes
Name
JPCC2019.pdf
Description
Accepted version
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5.86 MB
Format
Adobe PDF
Checksum (MD5)
3e8d3a7f4dad63ff0793fd7bef9346fa
Author(s)
Zhu, Tianyu
Van Voorhis, Troy
Date Issued
April 2019
Journal
Journal of Physical Chemistry C
Publisher
American Chemical Society (ACS)
Citation
Zhu, Tianyu, and Troy Van Voorhis. "Unraveling the Fate of Host Excitons in Host–Guest Phosphorescent Organic Light-Emitting Diodes." Journal of Physical Chemistry C 123, 16 (April 2019): 10167-702 doi 10.1021/ACS.JPCC.9B02820 ©2019 Author(s)
Version
Author's final manuscript
Abstract
Understanding the energy- and charge-transfer mechanisms in host-guest systems is crucial for improving the performance of organic light-emitting diodes (OLEDs), but it presents a theoretical challenge because of the disordered molecular environment. Here, we address the fate of excitons that form on the host in a 2,8-bis(triphenylsilyl)dibenzofuran-Ir(ppy)3 phosphorescent OLED through a quantum mechanics/molecular mechanics simulation. Our results demonstrate that triplet host excitons can be harvested through efficient energy transfer to the T1 state of the guest allowed by an excellent spectral overlap. A detailed analysis of the guest absorption spectrum uncovers the fact that high-lying guest singlet states play a critical role in utilizing singlet host excitons. Furthermore, we investigate the process where host excitons break up and re-form on the guest and show it is unfavored owing to the high energy barrier. This work thus reveals that energy transfer is the primary quenching mechanism for host excitons and highlights the strategies for a better host-guest design.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1021/ACS.JPCC.9B02820
