有機螢光剛硬分子之設計、合成、性質與應用

Abstract

近年已有許多研究投入於有機螢光材料，主要研究集中致力於發光效率的提升以及波段的調控。本論文的研究主軸，是利用引入較為剛硬與平面的分子結構，期許達到提升材料放光表現的效果。內容主要可分為兩部分： 第一部分專注於研究有機發光二極體中激發錯合物 (exciplex)中的電子受體 (acceptor)以及後續於有機金屬發光二極體之應用。以環狀5-苯基苯并[b]磷吲哚5-氧化物 (5-phenylbenzo[b]phosphindole 5-oxide) 為主結構之新型有機分子做為激發錯合物中的電子受體，並研究及探討其物理及化學性質。本設計企圖藉由引入較為剛硬的環狀核心結構，減低非輻射衰變，期許能提高以exciplex為發光機制的有機發光二極體元件之發光效率與元件表現。除了作為電子受體，上述分子也和錳合成有機金屬發光體，探討結構對於錯合物的放光與熱穩定性之影響。 第二部分則致力於合成近紅外光波段分子。主要以推電子基—拉電子基—推電子基 (Donor-Acceptor-Donor)為主體結構，並藉由調整推電子基的剛硬及平面性，達到提升放光效率的目的。拉電子基選用噻吩噻二唑(thienothiadiazole, TTD) 作為主要結構，搭配不同剛硬性推電子基，做出一系列放光在近紅外光波段的材料，並探討此類螢光分子之光物理特性。

In recent years, there have been many studies focused on organic fluorescent materials, with the main research efforts aimed at improving the emission efficiency and tuning the emission wavelength. The main focus of this thesis is to use more rigid and planar molecular structures to enhance the emissive performance of materials. The content can be divided into two parts: The first part focuses on studying the electron acceptors in exciplexes and their applications in organic metal-emitting diodes. A novel organic molecule based on a 5-phenylbenzo[b]phosphindole 5-oxide is used as the electron acceptor in exciplex system, and its physical and chemical properties are measured. The design attempts to reduce non-radiative decay by introducing a more rigid cyclic core structure, aiming to improve the emission efficiency and device performance of organic light-emitting diodes based on exciplex emission mechanism. In addition to being used as electron acceptors, the above-mentioned molecules are also used to synthesize organometallic emitters with manganese, and the effect of structure on the photoluminescent thermal stability of the complexes is investigated. The second part focuses on the synthesis of near-infrared (NIR) emitting molecules. The main structure is based on a donor-acceptor-donor (D-A-D) architecture, with adjustments made to the rigidity and planarity of the electron-donating group to improve the emission efficiency. Thienothiadiazole (TTD) is used as the main structure for the electron-accepting group, and a series of NIR-emitting materials are synthesized by incorporating electron-donating groups with different rigidities, and their photophysical properties are investigated.