本篇論文主要開發一系列以Donor-Acceptor-Donor結構之有機螢光染料，並深入探討其放大自發輻射（Amplified Spontaneous Emission， ASE）性質。 第一系列以噻唑並噻唑（Thiazolothiazole， TTAZ）作為中間受體核心，並以三種梯型聚對苯（Ladder-Type p-Phenylene）單元作為供體基團；並在表現優異的茚並芴供體基團與受體核心之間引入噻吩（Thiophene）與噻吩並噻吩（Thienothiophene）單元，合成一系列模型分子。其中，具有茚並芴供體基團之模型分子（2）展現較優異的光學表現及良好的溶解度，因此在第二系列中改變中間受體核心的拉電子能力，利用調控拉電子能力達到改變ASE放射波長之目的。第三系列為開發具有ASE性質的藍光染料，主要以螺雙芴氧雜蒽（Spiro[difluorene-xanthene]，簡稱Spiro-BiFL）結構作為核心，發現單純中間核心Spiro-BiFL（即模型分子（8））即有ASE的性質，且ASE波長為399 nm，閥值為192 μJ/cm²，接著加入不同推電子能力的基團，雖然會造成ASE波長紅移，卻能有效降低ASE閥值，最明顯的為模型分子（10），閥值為44.74 μJ/cm²，代表在D-A-D的分子結構設計下能有效降低閥值。 本論文也進一步分析改變激發波長對ASE閥值的影響，設計了可調式激發波長作為間接激發光源並量測染料ASE閥值。首先，此實驗以第二系列分子作為模型系統，進行實驗方法、光路架設與可行性驗證；接著，將此方法應用於本實驗室碩士畢業生高筠貽學姐所合成之三唑並喹喔啉（triazoloquinoxaline）核心染料模型系統中，系統性比較在溶液態下以氮氣雷射（337 nm）與最佳激發波長激發時之ASE閥值表現，並進一步分析ASE閥值與放光速率常數（radiative rate constant， kr）之關聯性。藉由上述研究，本論文驗證了激發波長的選擇對ASE閥值的重要性。;The study focuses on the design and development of a series of organic fluorescent dyes with donor–acceptor–donor (D–A–D) molecular structures， and systematically investigates their amplified spontaneous emission (ASE) properties. In the first molecular series， thiazolothiazole (TTAZ) was employed as the central acceptor core， while three different ladder-type p-phenylene units were introduced as donor group. To further modulate the molecular structure and optical properties， thiophene and thienothiophene units were incorporated as π-bridges between the Indenofluorene donor and the TTAZ acceptor core， leading to the successful synthesis of a series of model compounds. Among these molecules， compound (2)， bearing the Indenofluorene donor unit， exhibited superior optical performance and good solubility. Based on this result， the second molecular series was designed by varying the electron-withdrawing ability of the central acceptor core， with the aim of tuning the ASE emission wavelength through acceptor-core modulation. The third molecular series was developed to obtain blue-emissive fluorescent dyes with ASE characteristics. Spiro[difluorene-xanthene] (Spiro-BiFL) was selected as the central core structure. Notably， the pristine Spiro-BiFL core itself exhibited ASE behavior， with an ASE wavelength of 399 nm and a threshold of 192 μJ/cm². Subsequently， substituents with different electron-donating abilities were introduced into the molecular framework. Although the introduction of these donor groups caused a red-shift in the ASE wavelength， it effectively reduced the ASE threshold. In particular， compound (10) showed a significantly lower ASE threshold of 44.74 μJ/cm²， demonstrating that the D–A–D molecular design is an effective strategy for reducing the ASE thresholds. In addition to molecular design， this thesis further examines the influence of excitation wavelength on ASE threshold measurements. A tunable excitation-wavelength system was constructed and used as an indirect excitation source to measure the ASE thresholds of the fluorescent dyes. The second molecular series was first selected as a model system to establish the experimental method， optical setup， and feasibility of this approach. This method was then applied to a triazoloquinoxaline-based dye system previously synthesized in our laboratory by Yun-Yi Kao. The ASE thresholds measured in solution under excitation with a nitrogen laser at 337 nm were systematically compared with those obtained using the optimized excitation wavelength. Furthermore， the relationship between the ASE threshold and the radiative rate constant (kr) was analyzed. These results demonstrate that the choice of excitation wavelength plays an important role in the accurate evaluation of ASE thresholds in organic fluorescent dyes.
