| Abstract: | 我們成功合成以 dithieno[3′,2′:3,4;2′′,3′′:5,6]benzo[1,2-c]furazan (DTBF)為架橋，連接作為電子予體之苯胺，及2-cyanoacrylic acid作為電子受體兼錨基的新穎 D−A−A光敏化染料(JH-1至JH-5)。化合物合成的主要反應包括 Kumada Coupling、Hartwig-Buchwald coupling、Stille coupling、Vilsmeier-Haack reaction、Knoevenagel condensation。
除了探討化合物之光物理與電化學性質外，也進行理論計算，以及製成染料敏化太陽能電池，進行測試。這些化合物都展現電荷轉移特性，有助受光後之電子注入TiO2。由於染料在350−500 nm有不錯的吸收度，DTBF屬較大面積之平面結構，引入共軛架橋中之龐大烷基可能無法完全抑制分子之堆疊；因此，我們嘗試加入CDCA以抑制分子之堆疊。CDCA之加入確實提高了元件之效率；其中 JH-5元件有著卓越的光電轉換效率，高達 7.34%，可達標準元件 N719的 97%。
;New D-A-A type sensitizers (JH dyes), comprised of arylamine as the electron donor, dithieno[3′,2′:3,4;2′′,3′′:5,6]benzo[1,2-c]furazan (DTBF) containing conjugated segment as the conjugated bridge, and 2-cyanoacrylic acid as both the acceptor and anchor, have been synthesized. Kumada coupling, Hartwig-Buchwald coupling, Stille coupling, Vilsmeier-Haack reaction and Knoevenagel condensation reactions are used for the dyes synthese.
The physical properties of the new dyes were characterized by photophysical and electrochemical measurements, and theoretical computation. Dye-sensitized solar cells were also fabricated using new developed dyes as the sensitizers. The charge transfer character in the compounds is beneficial to the electron injection into TiO2 after photoexcitation. With good absorption in the spectral range from 350 to 500 nm, due to the presence of a large and flat DTBF entity in the spacer, the bulky alkyl chains in the dye molecule can not effectively suppress dye aggregation. Therefore, CDCA was added as the co-adsorbent to suppression dye aggregation. Addition of CDCA indeed improves the cell performance. DSSC of JH-5 has best efficiency of 7.34%, reaching 97% of the standard cell N719. |
