有機太陽能電池光作用層-高規則性聚噻吩�二氧化鈦奈米混成材料之合成與性質研究

Synthesis of Novel Regioregular Polythiophene /Titanium Dioxide Hybrid Materials as Photoactive Layer in Organic Solar Cells

呂學沛(Hsueh-Pei Lu)

指導教授 ： 芮祥鵬 ； 王立義

國立臺北科技大學/工程學院/有機高分子研究所/碩士(2006年)

摘要

用於製備有機太陽能電池（organic solar cell）之光作用層材料中，聚噻吩（polythiophene）及二氧化鈦（titanium dioxide），由於其適切的電子能階及優良的電荷傳導能力，而常分別被使用為良好的電子供體及電子接受體。然而，二者的性質迥異，若直接將兩種材料進行物理性摻合，將常導致嚴重的相分離現象，使得聚噻吩經光激發而生成的激子（exciton），未能產生良好的電荷轉移，而降低了元件的能量轉換效率。本研究中，我們首先合成2,5-dibromo-3-(6-bromohexyl)thiophene和2,5-dibromo-3-hexylthiophene兩種不同的單體，接著利用兩種單體不同莫爾比的進料量，配合Grignard metathesis法成功地聚合出多種不同單體比例的共聚物poly[3-(6-bromohexyl)thiophene-co-3-hexylthiophene]，並且其立體規則度皆大於95%，之後我們利用強鹼t-BuOK，針對共聚物上溴官能基進行脫去反應，將溴官能基完全的轉換為雙鍵基團，接著我們再利用聚合物上的雙鍵官能基與triethoxysilane上單獨與矽連接的氫，在催化劑H2PtCl6的催化下進行反應，成功地將矽氧烷基團鍵結在高規則度聚噻吩上，最後我們利用溶膠-凝膠反應（sol-gel）的方法製備有機/無機奈米混成材料( hybrid materials)，並且藉由控制TiO2前驅物之進料量，製備了多種不同TiO2固含量的混成材料。另外，我們以1H NMR鑑定材料的結構，並由凝膠滲透層析儀得到聚合物之平均分子量，再以紫外光譜儀分析材料的光學性質，並由SEM及TEM觀測材料的表面特性。

關鍵字

有機-無機混成材料 ； 高規則性聚噻吩 ； 光敏性材料

並列摘要

Polythiophene and titania are frequently used as good electron donor and electron acceptor in organic solar cells, respectively, due to their adequate energy levels and excellent charge transport properties. However, the compatibility between organic and inorganic materials is usually poor, thus usually leading to serious macro-scale phase separation upon blending. The main purpose of this thesis is to synthesize a class of hybrid materials with minor phase separation. In this study, both 2,5-dibromo-3-(6-bromohexyl)thiophene and 2,5-dibromo-3-hexylthiophene were first synthesized and employed as monomers to prepare a series of poly[3-(6-bromohexyl)thiophene-co-3-hexylthiophene] with various monomer ratios via Grignard metathesis . NMR spectra of copolymers indicated the stereo regioregularity for all polymers synthesized are greater than 95%. The terminal bromine groups in copolymers were transferred to double bonds by the elimination reaction using t-BuOK as reagent. Then, the product of poly[3-(6-triethoxysilyl)thiophene-co-3-hexylthiophene] were synthesized by treating the alkene-containing copolymers with triethoxysilane in the presence of H2PtCl6 catalyst. Chemical structures and molecular weight characteristics of monomers and polymers thus-prepared were analyzed by 1H NMR and GPC. Finally, novel grafted hybrids of poly[3-(6-triethoxysilyl)thiophene-co-3-hexylthiophene]/TiO2 were prepared by the in-situ sol-gel reaction of titanium(iv) n-butyloxide in the THF solution of poly[3-(6-triethoxysilyl)thiophene-co-3-hexylthiophene]. The chemical bonding between regioregular polythiophene side chain and TiO2 may provide an efficient route for preventing the occurrence of serious phase separation, thus leading to the increase in the efficiency of charge separation upon light illumination. Both TEM and SEM techniques were utilized to explore the morphology of these new hybrid materials.

並列關鍵字

Organic-inorganic hybrids ； Regioregular polythiophene ； Photoactive materials

參考文獻

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