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• 研究论文 • 上一篇    

热激活延迟荧光敏化荧光薄膜激发态弛豫:受体跃迁偶极矩的关键作用

杜敏1,郭子龙1,3,马骁楠1,杨文胜1,2   

  1. 1. 天津大学分子+研究院

    2. 河南大学纳米科学与工程研究院 3. 长春理工大学材料科学与工程学院

  • 收稿日期:2025-06-09 修回日期:2025-07-18 网络首发:2025-08-01 发布日期:2025-08-01
  • 通讯作者: 郭子龙 E-mail:zilong.guo@cust.edu.cn
  • 基金资助:
    国家重点研发计划(批准号:2020YFA0714603和2020YFA0714604)资助

Excited-State Relaxation in Thermally Activated Delayed Fluorescence-Sensitized Fluorescence Films: The Critical Role of Acceptor Transition Dipole Moment

DU Min1, GUO Zilong1,3, MA Xiaonan1, YANG Wensheng1,2   

  1. 1. Institute of Molecular Plus, Tianjin University

    2. Engineering Research Center for Nanomaterials, Henan University 3. School of Materials Science and Engineering, Changchun University of Science and Technology

  • Received:2025-06-09 Revised:2025-07-18 Online First:2025-08-01 Published:2025-08-01
  • Contact: Zi-Long GUO E-mail:zilong.guo@cust.edu.cn
  • Supported by:
    Supported by the National Key Research & Development Program of China(Nos. 2020YFA0714603 and 2020YFA0714604)

摘要: 在热激活延迟荧光敏化荧光(TSF)体系中,受体跃迁偶极矩(TDM)对激发态弛豫路径的影响尚不明确. 本研究通过构建受体TDM差异显著的TSF薄膜(DMAC-DPS/TMePh-BDP与AQ(PhDPA)2/DiEA-SQ),利用稳态/瞬态荧光技术系统探究了模型体系的激发态弛豫路径. 实验表明,TDM较大的DiEA-SQ通过增强光谱重叠积分扩大F?rster共振能量转移(FRET)半径(R0),从而有效抑制Dexter能量转移(DET). 值得注意的是,高TDM受体虽可抑制DET导致的无辐射弛豫,但其光致发光量子产率因自吸收(SA)效应而显著降低. 本研究指出,提升受体TDM是增强FRET效率并抑制DET的有效策略,但需设计具有更大斯托克斯位移的受体分子或结合光学结构以抑制SA效应. 这种机理层面的理解为TSF发光器件的设计提供了理论支撑.

关键词: 热激活延迟荧光敏化荧光, 跃迁偶极矩, F?rster共振能量转移, Dexter能量转移, 自吸收效应

Abstract: In thermally activated delayed fluorescence (TADF)-sensitized fluorescence (TSF) systems, the role of acceptor transition dipole moment (TDM) in governing excited-state energy relaxation pathways remains insufficiently understood. To elucidate this mechanism, we constructed TSF films with distinct acceptor TDMs (DMAC-DPS/TMePhBDP and AQ(PhDPA)2/DiEA-SQ) using PMMA as the host matrix. The excited state relaxation dynamics in these TSF systems were systematically investigated using steady-state and time-resolved fluorescence spectroscopy. The experimental results show that DiEA-SQ with larger TDM effectively suppresses Dexter energy transfer (DET) by enhancing the spectral overlap integral to extend the F?rster resonance energy transfer (FRET) radius (R0). Notably, while high-TDM acceptors can inhibit non-radiative relaxation caused by DET, their photoluminescence quantum yield significantly decreases due to the self-absorption (SA) effect. Our findings suggest that increasing acceptor TDM is an effective strategy to enhance FRET efficiency and suppress DET, but requires designing acceptor molecules with large Stokes shifts or targeted optical engineering is essential to mitigate SA effects. This mechanistic understanding provides critical insights for developing TSF optoelectronic devices.

Key words: TADF-sensitized Fluorescence, Transition Dipole Moment, F?rster Resonance Energy Transfer, Dexter Energy Transfer, Self-Absorbance

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