本論文合成出一系列非金屬系有機光敏染料(metal-free organic dye)。以「苯并三唑」(1,2,3-benzotriazole)為中心，在兩側引入呋喃(furan)、噻吩(thiophene)、硒吩(selenophene)等芳香雜環構成共軛架橋(spacer)，並以triphenylamine作為電子予體(electron donor)，2-cyanoacrylic acid為電子受體(electron acceptor)。 本系列之中心主體苯并三唑僅屬於一個medium band gap故此TZ系列吸收波長範圍座落在454−478 nm區間，短於以benzothiadiazole片段為中心之化合物。理論計算證實「苯并三唑」的確具有不易電荷累積特性，有利於電子的注入。經電化學與吸收光譜量測推算出此系列染料之HOMO與LUMO能階範圍分別約在1.01至1.12 V與-0.87至-1.08 V之間(vs NHE)，因此染料皆可順利將電子注入至TiO2光導電極以及隨後藉由電解質還原。此系列染料組裝成的染料敏化太陽能電池（dye-sensitized solar cells, DSSCs）的光電轉換效率為 4.37−6.2%。在相同條件下和 N719 染料製成的標準元件比較，可達標準元件效率的 60−85%。A series of metal-free dipolar organic dyes (TZ) have been synthesized. The conjugated spacer of the TZ dyes contains a 1,2,3-benzotriazole core, in which both sides are linked with the different heteroaromatic rings such as furan, thiophene, and selenophene. All of the compounds have a triphenylamine as the electron donor, and 2-cyanoacrylic acid as the electron acceptor.Being a medium band gap entity, 1,2,3-benzotriazole-based compound has a shorter absorption wavelength than that of benzothiadiazole congener, and the spectra falls in the range of 454 to 478 nm. Theoretical computation indicates that 1,2,3-benzotriazole has less tendency to trap electrons and is beneficial for electron injection. The HOMO (1.01 to 1.12 V vs NHE) and LUMO (-0.87 to -1.08 V vs NHE) levels calculated from electrochemical and optical data assure favorable electron injection and regeneration of the dye after electron injection. The power conversion efficiency of n-type DSSCs devises based on these dyes reach 4.37−6.2% on. These values are 60−85% of the standard cell based on N719 (7.19%) fabricated and measured under similar coonditions.
