Solid-state Effects on Luminescence Properties of TADF Emitters Based on Pyrido[2,3-b]pyrazine-Dihydrophenazasilines Donor-acceptor Structures:Theoretical Study  

固态效应对吡啶并[2,3-b]吡嗪-二氢苯并氮杂环类给-受体结构TADF分子发光性质影响的理论研究

作　　者：LI Yuheng LIU Meiqi HOU Baoming PAN Yuyu YANG Bing 李煜恒;刘美琪;侯宝明;潘玉钰;杨兵(沈阳工业大学石油化工学院,辽宁辽阳111003;吉林大学化学学院超分子结构与材料国家重点实验室,吉林长春130012)

机构地区：[1]School of Petrochemical Engineering,Shenyang University of Technology,Liaoyang 111003,China [2]State Key Laboratory of Supramolecular Structure and Materials,College of Chemistry,Jilin University,Changchun 130012,China

出　　处：《发光学报》2025年第2期354-365,共12页Chinese Journal of Luminescence

基　　金：国家自然科学基金(51603127);辽宁省教育厅面上项目(JYTMS20231248)。

摘　　要：Thermally activated delayed fluorescence(TADF)molecules have outstanding potential for applications in organic light-emitting diodes(OLEDs).Due to the lack of systematic studies on the correlation between molecular structure and luminescence properties,TADF molecules are far from meeting the needs of practical applications in terms of variety and number.In this paper,three twisted TADF molecules are studied and their photophysical properties are theoretically predicted based on the thermal vibrational correlation function method combined with multiscale calculations.The results show that all the molecules exhibit fast reverse intersystem crossing(RISC)rates(kRISC),predicting their TADF luminescence properties.In addition,the binding of DHPAzSi as the donor unit with different acceptors can change the dihedral angle between the ground and excited states,and the planarity of the acceptors is positively correlated with the reorganization energy,a property that has a strong influence on the non-radiative process.Furthermore,a decrease in the energy of the molecular charge transfer state and an increase in the kRISC were observed in the films.This study not only provides a reliable explanation for the observed experimental results,but also offers valuable insights that can guide the design of future TADF molecules.热激活延迟荧光(TADF)分子在有机发光二极管(OLED)中具有突出的应用潜力。但是,由于缺乏对分子结构与发光特性相关性的系统研究,TADF分子在种类和数量上远不能满足实际应用的需要。本文在实验基础上研究了三种扭曲的TADF分子,基于TVCF方法结合多尺度计算对分子的光物理性质进行了理论预测。结果表明,所有分子都表现出较高的反向系间窜越速率kRISC,从而印证了研究分子的TADF发光特性。此外,作为给体单元的DHPAzSi与不同的受体单元结合会改变基态和激发态的扭曲角,而受体的平面度与重组能呈正相关,这一性质对非辐射跃迁过程有很大影响。此外,在薄膜中还观察到分子电荷转移态能量的降低和kRISC的增加。这项研究不仅为实验结果提供了可靠的解释,还为未来TADF分子的设计提供了指导。

关 键 词：solid-state effects thermally activated delayed fluorescence(TADF) theoretical study multi-scale simulation 

分 类 号：O482.31[理学—固体物理]