以噻唑並噻唑及苯並咪唑為主體之有機功能性材料的設計、合成與應用

Abstract

近年來有機小分子材料的研究蓬勃發展，無論在生醫或光電領域皆有廣泛的應用。本篇論文以推電子基 (Donor, D) 與拉電子基 (Acceptor, A) 之組合調控分子的吸收光波段，以期得到理想材料性質，內容主要分為兩部分： 第一部分著重於遠紅光分子的設計與其化學放光應用。化學放光不需外加激發光源，相較於螢光顯影更能提升在生物體中的訊噪比，因此具生物顯影潛力。本研究以噻唑並[5,4-d]噻唑 (Thiazolo[5,4-d]thiazole, Tz) 作為核心，合成出 D-A-A'-A-D 結構分子，並藉由增強電子受體的拉電子性質使分子吸放光波段紅移。再使用高分子界面活性劑 F127 將此系列分子與雙[3,4,6-三氯-2-(戊氧基羰基)[苯基]草酸酯 (bis[3,4,6-trichloro-2-(pentyloxycarbonyl) phenyl]oxalate, CPPO) 共同包裹形成奈米粒子，與雙氧水反應可產生化學放光，期望能應用於生物體內癌細胞顯影。 第二部分致力於開發鈣鈦礦太陽能電池之鈍化劑。鈣鈦礦太陽能電池具有光吸收係數高與製作容易等優勢，然而在溶劑製程中會產生缺陷，導致其穩定性下降。本研究以1,3-二甲基苯並咪唑碘化物 (1,3-dimethylbenzimidazolium iodide) 單元修飾 D-A 分子中電子受體，D-A 結構容易調控電子密度分佈，使有機陽離子更能與鈣鈦礦陰離子結合，分子中碘離子亦能填補鈣鈦礦晶體的空缺。將此系列分子作為鈍化劑加入鈣鈦礦太陽能電池之中，進一步探討元件性質，期望提升電池能量轉換效率。

Organic small molecular materials for biomedical and photovoltaic application have been developed in recent years. Here in, novel molecules were designed by modifying donor (D) and acceptor (A), aiming to achieve ideal material properties. The first part of the thesis focuses on the design of deep-red molecules and their chemiluminescence (CL) applications. Compared to fluorescence imaging, CL imaging can achieve a higher signal-to-noise ratio due to the elimination of external excitation light. A series of novel molecules with D-A-A’-A-D structure were designed for CL senor, while the thiazolo[5,4-d]thiazole (Tz) group was selected as the cores. By enhancing the electron-withdrawing property of the A part, the molecules exhibit red-shifted absorption and NIR emission. These molecules were encapsulated into polymeric surfactant F127 along with bis[3,4,6-trichloro-2(pentyloxycarbonyl)phenyl]oxalate (CPPO) to form biocompatible nanoparticles, which can react with hydrogen peroxide to release CL. This result suggests that the CL system is a potential candidate for biological applications. In the second part, we dedicated to developing passivators in perovskite solar cells (PSCs). Organometal halide perovskites were inherent materials for photovoltaic devices because of their strong light-absorption coefficients and low cost. However, defects generated during the solution process result in lower stability of PSCs. Here in, 1,3-dimethylbenzimidazolium iodide was connected to the D-A structure, which exhibits a tunable electron density distribution, allowing organic cations to better bind with perovskite anions. Additionally, the iodide ions in these molecules can passivate ionic defects within the perovskite. These molecules are used as passivators in PSCs, and the device properties are further investigated.