臺灣大學: 高分子科學與工程學研究所林唯芳黃子佳Huang, Tzu-ChiaTzu-ChiaHuang2013-03-292018-06-292013-03-292018-06-292012http://ntur.lib.ntu.edu.tw//handle/246246/254430由於isoindigo是一種可再生的材料且可從植物中獲得取得，使得isoindigo系列的導電高分子在近年來引起來廣泛的研究興趣。為了探討側鏈效應對於導電高分子在高分子太陽能電池的性質影響，在這項工作中，我們利用施蒂勒偶和反應(the Stille cross-coupling reaction)合成了一系列以cyclopentadithiophene（CPDT）為弱電子予體，isoindigo（I）為強電子受體的可溶性低能隙高分子 (PCI)，並分別接上兩種側鏈，辛基 (octyl，8)和2 -乙基己基 (2-ethylhexyl，e)。我們將側鏈效應對於此系列導電高分子的光電特性，光伏元件表現和薄膜形態的影響分別進行了探討。當將此系列的高分子上的側鏈從直鏈改變成支鏈，其吸收光譜最高有超過30奈米的藍位移，能階分布和能隙變化最高超過0.2電子伏特。而當改變側鏈形狀時，可觀察到不同的富勒烯優化比例。當高分子的isoindigo單元上的側鏈為直鏈時，富勒烯比例為66 %，而當其為支鏈時則為50 %。我們將側鏈效應對於此系列高分子的光伏元件效率表現做了一系列的定量分析。此分析將暗電流的指數前因子Jso─在聚合物/富勒烯的共混物分子間的相互作用關係─分別與開路電壓(Voc)與短路電流(Jsc)之間的關係進行了定量證明，得到Jso分別與Voc呈負相關，與Jsc則呈正相關的關係。並利用此關係解釋側鏈改質對於光伏元件性質表現的影響。當高分子上的側鏈為直鏈時，可促進聚合物/富勒烯的共混物分子間的相互作用，增加Jso，而當高分子上的側鏈為支鏈時則反之。因此，此系列高分子中，PCeI8的側鏈設計，CPDT單元上為支鏈，isoindigo單元上為直鏈，可優化Jso得到最佳值，進而在Voc與Jsc之間取得平衡，得到目前最高的能源轉換效率，3.6％。此結果可再透過元件的製程優化而提升。Isoindigo based conducting polymers have attracted extensive interests for polymer solar cell application due to the isoindigo is a renewable raw material and available from plant. We have synthesized a series of soluble low band gap isoindigo based polymers (PCI) with cyclopentadithiophene (CPDT) as weak donor unit and isoindigo (I) as strong acceptor unit, decorated with two kinds of side chains, octyl and 2-ethylhexyl, via the Stille cross-coupling reaction. The side chain effect of this conducting polymer on the performance of polymer solar cell has been quantitatively investigated. By changing the side chain of polymers from linear to branch, the λmax of absorption can be blue-shifted for more than 30 nm, the energy level and electronic band gap can be varied by more than 0.2 eV. In addition, the weight ratio with fullerene of optimized efficiency varies with the shape of side chains. Higher ratio (66 %) of fullerene could be observed from polymers with linear side chain on isoindigo unit whereas low ratio of fullerene (50%) was observed in polymers with branched side chains on isoindigo unit. The relationships of pre-exponential dark current term Jso, which accounts for the intermolecular interactions in the polymer/PCBM blends, to Voc and Jsc respectively, were quantitatively determined. The Voc is negatively proportional to Jso, whereas Jsc is positively proportional to Jso. The relationships were applied to the elaboration of the impact on photovoltaic performance done by side chain. The Jso could be improved when linear side chains are attached to polymers but weakened when branched side chains are attached. Therefore, the side chain design of polymer PCeI8, with branched side chains on CPDT units and linear side chains on isoindigo units, could optimize Jso to achieve the balance between Voc and Jsc and thus results in the highest power conversion efficiency (PCE) of 3.6 % by far. The power conversion of efficiency of this type polymer could be further improved by optimizing the fabrication condition.2532287 bytesapplication/pdfen-US異靛藍電子予體-受體共軛高分子低能隙側鏈效應高分子太陽能電池isoindigodonor-acceptor conjugated polymerside chain effectlow band gappolymer solar cell[SDGs]SDG7thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/254430/1/ntu-101-R99549025-1.pdf