基于给受体的有机热致延迟荧光（TADF）材料的理论研究

发布时间：2023-01-30 13:56

　　开发具有优异性能的新型有机电致发光材料是材料化学的一个重要目标。最近,热致延迟荧光（TADF）材料正在蓬勃发展成为用于有机发光二极管（OLED）和其他光电器件的极具潜力的下一代有机电致发光材料。TADF-OLED已经用于照明和显示技术以及传感应用和荧光显微镜。由于其通过有效的反向系间窜越（RISC）过程同时捕获单重态和三重态激发态来产生光,达到理论量子效率的最大化,因而代表了当前有机电子学研究的一个活跃领域。最低单重态（S₁）和三重态（T₁）激发态之间小的能级差(ΔE_ST)是衡量TADF高效率并可能提高器件内量子效率（IQE）的重要标准。在Adachi等人研制了具有优良性能的TADF-OLED器件之后,基于分子设计的架构理念取得了巨大的进步和蓬勃发展。尽管在设计具有高光致发光量子产率（PLQY）的TADF材料和验证其在具有高外量子效率（EQE）的OLED器件中的适应性方面都取得了显着成就,但是必须指出有机TADF材料的深层设计需要通过密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）来辅助,用以揭示内在机制,提高设... 

【文章页数】：145 页

【学位级别】：博士

【文章目录】：
Abstract
摘要
Chapter1:Introduction
    1.1 History and Background of TADF
    1.2 Introduction to OLED
        1.2.1 Types of OLED
        1.2.2 Working Principle
    1.3 Importance and Applications for TADF-OLEDs
    1.4 Basic Concepts of TADF Phenomenon
        1.4.1 Harvesting Excitons via Delayed Singlet Emission
        1.4.2 Mechanism of TADF Process
        1.4.3 The Intersystem crossing(ISC) (S1→ T1)
        1.4.4 The Reverse intersystem crossing(RISC) (T1→ S1)
        1.4.5 Temperature Dependence of TADF
        1.4.6 Minimizing the singlet-triplet energy splitting(ΔEST)
        1.4.7 Colour of TADF Emitter
    1.5 Molecular Design Principles
        1.5.1 Essential Donor Moieties:
        1.5.2 Essential Acceptor Moieties:
            1.5.2.1 Triazine-based TADF emitters
            1.5.2.2 Spirobifluorene and Spiro-acridine based TADF emitters
            1.5.2.3 CBCD(Cz-PN)based TADF emitters
            1.5.2.4 Biaryl Sulfones/Diphenyl Sulfoxide based TADF emitters
            1.5.2.5 Diphenyl Ketone based TADF emitters
            1.5.2.6 Boron based TADF emitters
    1.6 Challenges for achieving highly efficient TADF-OLEDs
    1.7 Aims and objectives of this dissertation:Structure and scope
Chapter2:Computational Methodology(Quantum Chemical Methods)
    2.1 Development of quantum chemistry
    2.2 The Schr?dinger Wave Equation(SWE)
    2.3 Hartree-Fock(HF)Theory
    2.4 Density Functional Theory(DFT)
    2.5 Time-Dependent Density Functional Theory(TD-DFT)
    2.6 Basis Set
Chapter3:Theoretical investigations of the realization of sky-blue to blue TADF Materials via CH/N and H/CN substitution at the Diphenylsulphone acceptor
    3.1 Introduction
    3.2 Computational Method
    3.3 Results and discussion
        3.3.1 Optimized structures at S0 and S1 states
        3.3.2 Frontier molecular orbitals
        3.3.3 Singlet-triplet energy gap
        3.3.4 Photophysical properties
    3.4 Conclusions
Chapter4:Rational design of triptycences as high performance thermally activated delayed fluorescence materials
    4.1 Introduction
    4.2 Computational methodology
    4.3 Results and discussion
        4.3.1 Molecular geometries in the ground and excited states
        4.3.2 Frontier molecular orbitals
        4.3.3 Singlet-triplet energy gap
        4.3.4 optical properties
        4.3.5.Charge injection and transport analysis
    4.4 Conclusions
Chapter5:A theoretical study of the influence of engineering the linker between the donor and acceptor fragments on the TADF characteristics
    5.1 Introduction
    5.2 Computational Methodology
    5.3 Results and Discussion
        5.3.1 TheΔEST and HOMO-LUMO overlap
        5.3.2 Photophysical properties
        5.3.3 Frontier Molecular Orbital Analysis
        5.3.4 Natural Population Analysis(NPA)and theΔEST
        5.3.5 Electron excitation analysis(Transition Characteristics)
        5.3.6 Exciton binding energy
        5.3.7 Charge injection and transport analysis
    5.4 Conclusion
References for chapter1
References for chapter2
References for chapter3
References for chapter4
References for chapter5
ACKNOWLEDGMENTS
DEDICATION
During the school,article has been(to be)published


【参考文献】：
期刊论文
[1]Theoretical predication for transition energies of thermally activated delayed fluorescence molecules[J]. Xiaohui Tian,Haitao Sun,Qisheng Zhang,Chihaya Adachi.  Chinese Chemical Letters. 2016(08)



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