含苯並噻雙唑側鏈之卡唑高分子衍生物之合成及其光電特性

Syntheses and Photovoltaic Characterizations of Polycarbazole Derivatives with Benzothiadiazole Side Chain

吳韋霖(Wei-Lin Wu)

指導教授 ： 謝國煌

國立臺灣大學/工學院/高分子科學與工程學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.10365

摘要

本研究目的為合成出帶有苯並噻雙唑(Benzothiadiazole)側鏈的卡唑單體，再透過Yamamoto反應聚合均聚物(Homopolymer) P1，以及利用Stille反應與雙錫官能機的噻吩共聚成共聚物(Copolymer)P2。由凝膠滲透層析儀(Gel permeation chromatography, GPC)分析結果，P1之重量平均分子量(M¬¬w)為3775 g/mol而P2之Mw分佈在1000~2000 g/mol左右。熱重分析(Thermogravimetry analysis)結果則顯示P1和P2足以耐熱至200 oC以上，具有很好的熱穩定性。由光學性質的測試，P1和P2由於都帶有分子內的電子予體/電子施體(Donor/Acceptor)結構，所以在紫外-可見光(UV-visible)吸收光譜皆有兩個特性吸收峰，從光譜上可得出P1及P2之能隙(Band gap)分別為2.33 eV及2.38 eV。經循環伏安法(Cyclic voltammetry, CV)測試電化學性質，P2比P1擁有更高的氧化電位(1.3 eV)，表示引入噻吩共聚可以有效提升分子的抗氧化性質，同時具有較低的最高電子填滿軌域(Highest occupied molecular orbital, HOMO)能階，較有機會作為高效率的高分子太陽能電池材料。

關鍵字

低能隙 ； 異質接面 ； 電子施體/受體 ； 太陽能電池 ； 共軛高分子

並列摘要

In this studies, carbaozle derivative monomers with benzothiadiazole side chain were synthesized and polymerized. Two novel polymer, Poly[9-(2,5-bis(hexyloxy)-4- (4-(5-methyl- thiophen-2-yl)benzo[c][1,2,5]thiadiazol-7-yl)phenyl)-9H-carbazole] (P1)
and poly[9-(2,5-bis(hexyloxy)-4-(4-(5-methyl-thiophen-2-yl)benzo[c][1,2,5]thiadiazol-
7-yl) phenyl)-9H-carbazole-alt-thiophene] (P2) were synthesized via Yamamoto coupling and Stille coupling reactions. According to thermogravimetry analysis, P1 and P2 possess great thermal stability. Due to the intramolecular electron donor-acceptor structure, the UV-visible absorption spectrum of polymers have two significant peak. From the absorption spectrum, P1 exhibits lower band gap (2.33 eV) than P2 (2.38 eV). In electrochemical analysis, copolymer P2 possesses lower highest occupied molecular orbital (HOMO) level (-5.57 eV) than homopolymer P1 (5.16 eV). Althogh P2 has higher band gap, P2 has lower HOMO which is essential parameter for high efficiency polymer solar cells. From the above analysis, carbazole derivatives with benzothiadiazoel side chain have potential for applications of polymer photovoltaics.

並列關鍵字

Low band gap ； Bulk heterojunction ； Electron donor/acceptor ； Solar cells ； Conjugated polymers

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