| 摘要: | 聚噻吩在共軛高分子系統中是結構型態最豐富的高分子之一，其結構上的多變性也同時使其性質，如半導體特性、導電性、發光性、熱穩定性…等之變化多采多姿。本實驗即藉由調變聚噻吩系統的結構來改變其能隙(band gap energy)以探討共軛高分子結構與能帶性質的關係。其中有潛力應用在藍光高分子發光二極體（PLED）與有機場效電晶體（OFET）的高、低能隙共軛高分子，將是強調的重點。利用有機合成策略在聚噻吩的主鏈或側鏈上接吡啶環(pyridine or phenanthroline)來減低聚噻吩的共軛長度，提高其能隙以合成高能隙聚噻吩衍生物；抑或形成環狀結構來降低能隙。本研究以低能隙之聚雙噻吩環戊烷（cyclopentadithiophene）為主體，並在環戊烷上引進烷基以增加高分子的溶解度，合成六種聚雙噻吩環戊烷衍生物，分別為poly(4,4-Dioctylcyclopenta[2,1-b:3,4-b]dithio-phene) （PDOCP）Poly(4,4-Dioctylcyclopenta[2,1-b:3,4-b]dithiophene- alt-pyri-dine)（PDOPy）、 poly(4,4-dioctyl-cyclopentadithio- phene-alt-3,8-Phenanthrolin) （PDOPh）、poly(4,4-dioctylcyclo- pentadithiophene-alt-Cyclopenta[2,1-b:3,4-b]dithiophene-4- one) （PDOCK）、poly(4,4-dioctyl-cyclopentadithiophene-alt- 3-octyl-thiophene（PDOOT）及poly(4,4-dioctyl-cyclopentadi- thiophene-alt-2-thio-phene)（PDOTh）。這些高分子除PDOCP是由氧化聚合合成外，其餘皆是利用不同單體進行A-B type Stille coupling共聚合而成的，共聚物之能隙與所組成之個別單一高分子之能隙有關，但不全然是介於個別單一高分子之間，顯示決定共聚高分子能隙的因素很複雜，無法單從其組成預測。 Polythiophenes are a series of conjugated polymers with diverse structure. The structure related properties, such as semiconducting, electric, luminescent properties, and thermal stability change accordingly. The objectives of this work are the preparation of polythiophenes with various band gap energies via structure modification. The target polymers for the applications in polymeric light emitting diode (PLED) and organic field effect transistor (OFET) were focused. The pyridine ring was added into the mail chain of polyalkylthiophenes to increase the band-gap energy of the polymer; or forming the fused-ring to reduce the band gap. We used the low band gap polymer polycyclopentadithiophene as a starting polymer and introducing an alkyl chain on the cyclopentane ring to increase its solubility, six A-B type copolymers of polycyclopentadi- thiophene derivatives such as poly(4,4-Dioctylcyclopenta[2,1-b:3,4-b] dithiophene) (PDOCP)、Poly (4,4-Dioctylcyclopenta [2,1-b:3,4-b] dithiophene)-Co-Py-ridine) (PDOPy)、poly (4,4-Dioctylcyclopenta-dithio- phene-alt-3,8-Phe-nanthrolin) (PDOPh)、poly (4,4-Dioctylcyclo- penta- dithiophene-alt-cyclopenta[2,1-b:3,4-b]dithio-phene-4-one) (PDOCK)、poly(4,4-Dioctyl-cyclopentadithiophene-alt-3-octyl-thiophene) (PDOOT) and poly (4,4-dioctyl-cyclopentadithiophene-alt-2-thiophene) (PDOTh) were synthesized. It was found that the band-gap energies of A-B type copolymers are not all fall inbetween its individual homopolymer. These results indicated that the band structure of A-B type copolymer is very complicated. It can not be predicted simply form just the structures of the polymers. |
