以三唑衍生物為核心之非富勒烯受體之設計、合成與應用

Abstract

太陽能是再生能源中最具潛力的一種能源，而有機太陽能電池在太陽能應用領域當中，具備了低成本、輕量化、可大面積製作、可撓曲等優點。近年來因眾多團隊在分子設計上與元件製程的努力，使得有機太陽能電池的光電轉換效率不斷創下新高的紀錄。 在本論文中，第一部分設計了容易調整能階與光電特性的非富勒烯的非稠環受體分子，以萘并[1,2-d:5,6-d']雙([1,2,3]三唑)作為核心結構，透過噻吩並[3,2-b]噻吩作為電子予體，末端引入兩種拉電子基團，設計出A-D-A’-D-A架構的分子，分別合成出EH-NTzTTID、EH-NTzTT2F兩個分子。由於兩分子的溶解度不佳，我們嘗試將分子核心上的碳鏈延長，以改善溶解度的問題，合成出溶解度較佳的OD-NTzTTID、OD-NTzTT2F兩個分子。其中OD-NTzTT2F的最大吸收波長在656 nm，消光係數為176500 M-1 cm-1。將OD-NTzTT2F以微量添加的形式，與PM6:Y6共混製作成三元有機太陽能電池，其光電轉換效率超過16.2%。 第二部份則是繼續改善OD-NTzTT系列分子的溶解度，將末端引入帶電荷基團，合成出OD-NTzTTMPPF6。以乙腈為溶劑的狀況下，在動態光散射中獲得最小的奈米粒徑為70 nm，嘗試與PM6:Y6共混製作成三元有機太陽能電池，其光電轉換效率略降至15.4 %，但元件的填充因子為75.7 %有顯著上升的趨勢，說明該帶電荷的非富勒烯受體材料在三元有機太陽能電池還是有潛力的。

Solar energy is one of the most promising renewable energies. In solar energy applications, organic photovoltaics (OPVs) have several advantages including low cost, lightweight, large-area production capability and flexibility. Recent advancements in molecular designs and methods for device fabrications have led to significant improvements in the power conversion efficiency (PCE) of OPVs. In this thesis, the first part focuses on the design of non-fullerene non-fused acceptor molecules with easy tunable energy levels and photovoltaic properties. Two A-D-A’-D-A-configured molecules, EH-NTzTTID and EH-NTzTT2F were synthesized with the core structure based on naphtho[1,2-d:5,6-d']bis([1,2,3]triazole) (NTz), thieno[3,2-b]thiophene (TT) as the donor and two electron-withdrawing end groups. Due to the poor solubility, synthetic efforts were made to improve their solubility by elongating the carbon chain on the NTz core, resulting in better soluble molecules, OD-NTzTTID and OD-NTzTT2F. OD-NTzTT2F exhibited a maximum absorption wavelength at 656 nm with an extinction coefficient of 176500 M-1 cm-1. By incorporating a trace amount of OD-NTzTT2F into the PM6:Y6 blend , a ternary OPV with PCE exceeding 16.2% was fabricated. The second part aimed to further improve the solubility of the OD-NTzTT series molecules by introducing charged end groups, leading to the synthesis of OD-NTzTTMPPF6. In acetonitrile, OD-NTzTTMPPF6 aggregates into into a minimum nanoparticle size of 70 nm observed by the dynamic light scattering (DLS). Although the PCE decreased to 15.4% when incorporated OD-NTzTTMPPF6 with PM6:Y6 into a ternary organic solar cell, the fill factor significantly increased to 75.7%, indicating the potential of this charged non-fullerene acceptor material for use in ternary OPVs.