| 摘要: | 本研究延伸自pBCN[34]結構，合成且鑑定不同側鏈取代基(烷基、醚烷基、硫醚烷基)在苯并二噻吩以及噻吩與噻吩并噻吩取代丙烯腈的共聚高分子，一系列是腈基 (Cyano group) 靠近噻吩并噻吩 (Thienothiophene) 的pBIC、pBIO與pBIS (pBIX)，另一系列是Cyano group 遠離Thienothiophene的pBOC、pBOO與pBOS (pBOX)。
熱性質的探討中，熱裂解溫度 (Td) 與玻璃轉換溫度 (Tg) 的差異是由於烷基、醚烷基、硫醚烷基的鍵能強度不同，使其較容易或不易振動或轉動。
在 UV-vis 吸收光譜圖中，取代基相同的情況下，pBOX都較pBIX為紅位移，推測是Cyano group位置的差異造成有效共軛長度差異。Cyano group位置相同的情況下，UV-vis 吸收光譜圖中紅位移程度皆是：醚烷基 > 硫醚烷基 > 烷基；能隙大小為：醚烷基 < 硫醚烷基 < 烷基，三種不同側鏈取代基影響分子能階較明顯的是在HOMO能階，以醚烷基高分子的最高，烷基高分子的最低，推測是高分子的推電子能力差異，以及單體π共軛共平面性不同造成的。每個高分子在薄膜狀態下吸收與其在溶液狀態下的吸收較為紅位移，高分子間的排列在少了溶劑的阻隔後，使其堆疊較緊密。
元件結構為ITO/ZnO/Polymer : PC61BM (w:w = 1:1)/MnO3/Ag之反式單層異質接面的有機光伏電池，其中pBOC的光電轉換效率可達到5.03 %、開路電壓為0.97 V、短路電流為9.26 mA/cm2、填充因子為55.94 %。而我們實驗室使用pBCN以相同元件結構的有機光伏電池的光電轉換效率為4.44 %、開路電壓為0.86 V、短路電流為8.17 mA/cm2、填充因子為63.28 %。;We have Synthesis and Characterization of Benzodithiophene (BDT) and (Thienothiophene-2,5-diyl)bis(thiophenyl)acrylonitrile (TTDCN) based Copolymers with Varying Side-Chain Substituent (Alky, Alkoxyl, Alkylthio). A series is pBIC, pBIO and pBIS (pBIX) that cyano group close to thienothiophene, another series is pBOC, pBOO and pBOS (pBOX) that far from thienothiophene cyano group.
About the thermal properties, the difference of thermal decomposition temperature (Td) and glass transition temperature (Tg) are due to the banding energy would make the polymers to vibration.
In the case of UV-vis absorption spectra, pBOX are red shift than pBIX. It may cause by the location of cyano group in the polymers. When the cyano group under same location of the polymers, the degree of red shift is Alkoxyl > Alkylthio > Alky; the degree of band gap (Eg) is Alkoxyl < Alkylthio < Alky ; Alkylthio polymers (pBIO, pBOO) have highest HOMO energy level, and Alky polymers (pBIC, pBOC) have lowest HOMO energy level. It is due to the difference of electron-donating ability and planarity. Absorption of film are red shift than absorption of solution is impacted by intermolecule π-π stacking.
Devices of inverted bulk heterojunction organic photovoltaics are based on ITO/ZnO/Polymer : PC61BM (w:w = 1:1)/MnO3/Ag. The best power conversion effciency of pBOC is 5.03 %, open circuit voltage of 0.97 V, short circuit current of 9.26 mA/cm2, fill factor of 55.94 %. pBCN is 4.44 %, open circuit voltage of 0.86 V, short circuit current of 8.17 mA/cm2, fill factor of 63.28 %. |
