• Photonics Research
  • Vol. 9, Issue 5, 05000865 (2021)
Zhen Chen1, Qian Zhou1, Huitian Du1, Yuan Yu1, Chuang Zhang2, Shenghao Han1, and Zhiyong Pang1、*
Author Affiliations
  • 1School of Microelectronics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
  • 2Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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    Abstract

    Two-photon excited fluorescence materials usually suffer from inefficient two-photon absorption (TPA) and nonradiative excited states. Here, upconversion fluorescence in an electron donor-acceptor (DA) exciplex doped with fluorescent emitters are systematically investigated. It has been found that the undoped DA exciplex exhibits enhancements of ~129% and ~365% in upconversion fluorescence compared to donor- and acceptor-only systems, respectively. Interestingly, photoluminescence quantum yields (PLQYs) up to ~98.65% were measured and immensely enhanced upconversion fluorescence was observed after doping various fluorescent emitters into the DA exciplex. Our results reveal the existence of two-photon excited energy harvesting in a thermally activated delayed fluorescence (TADF) DA exciplex doped with fluorescent emitters, via reverse intersystem crossing followed by rapid F?rster resonance energy transfer. Moreover, the additional gain mechanism related to intermolecular CT interaction that occurs at the TPA stage is found in the TADF DA exciplex system.
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    Zhen Chen, Qian Zhou, Huitian Du, Yuan Yu, Chuang Zhang, Shenghao Han, Zhiyong Pang. Immensely enhanced color-adjustable upconversion fluorescence in electron donor-acceptor exciplex chromophores doped with fluorescent emitters[J]. Photonics Research, 2021, 9(5): 05000865
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    Category: Optical and Photonic Materials
    Received: Oct. 19, 2020
    Accepted: Mar. 9, 2021
    Posted: Mar. 9, 2021
    Published Online: May. 7, 2021
    The Author Email: Zhiyong Pang (pang@sdu.edu.cn)