導電高分子柔軟、可撓曲的機械特性，被視為軟性電子產品主要材料之一。自1980 年代發現此材料後，學術界對導電高分子的研究蔚為風潮，並開創了有機電子學領域，開發出了有機電晶體、有機發光二極體、有機太陽能電池等等的元件，然而，可撓曲的迷人特性同時也缺乏剛性，因此讓形貌相依的電子結構缺陷劇增，造成電子傳導效率低落，時至今日，導電效率低仍是有機電子學領域中的最大瓶頸。
由固態物理學中可知，長程有序的結晶結構可使相鄰原子的電子軌域高度重疊產生交互作用，因而形成非侷域化(delocalized)之電子結構。但因為導電高分子為一種半結晶的材料，混雜了有序結晶區域以及無序區域，使得電子軌域重疊度下降因而形成侷域性(localized)電子結構，其中載子多以跳躍(hopping)方式傳輸，並受到結晶缺陷、晶界、非晶區域等散射中心減低傳導效率。再者，導電高分子會透過主鏈中的π-π內聚(cohesive)作用力結晶成長，導電高分子的內聚力屬微觀尺度的作用力，因此在巨觀元件尺度將以無方向性結晶成長於基板上，形成多晶形貌，各晶粒方向與傳導方向不一致，使得載子傳輸經歷更多的散射，因此，載子傳導效率低是可以預期的。
本研究使用的材料為Poly(3-hexylthiophene) (P3HT),是以噻吩為單元之共軛高分子。為了解決上述載子傳導效率不彰的問題，我們以三明治(Sandwichstructure)液態成膜系統製造高有序性之奈米纖維，利用經過表面處理的玻璃基材毛細拉力，加上基板表面之奈米溝槽結構，限縮可結晶的自由度，促使高分子沿特定方向長晶；在沉積過程中，單分子層預先改質的基板表面會與高分子產生交互作用力，使高分子更容易沉積至表面，最後可提升製程溫度，增加溶劑-高分子交互作用力，進而降低高分子本身不受控的無序團聚，延展的高分子主鏈更有利於單分子層對高分子的排列行為。在此架構下，可透過操作分子間作用力來調控分子之排列方向，原子力顯微鏡可觀測到巨觀上高度有序的奈米纖維，並以偏振拉曼頻譜驗證P3HT 主鏈在微觀的分子排列，最後利用有機場效電晶體量測載子在通道內的遷移率，由此證實了高度有序之表面形貌對載子遷移率的提升有莫大之影響。本研究從微觀有序的分子結構出發，藉由調控分子間作用力來形成有序分子排列，並對應巨觀有序的纖維形貌，最後以電晶體量測載子遷移率連結有序電子結構的效能，透過製程精密操作分子，為有機電子學領域的發展推進重要的一步。

With impressive mechanical property, conducting polymer is considered to be the main material of next generation consumer electronics. However, poor charge transport performance is the bottleneck of organic electronics. Charge carriers adopt hopping as main transport type because of the coexistence of amorphous and crystalline region. In addition, Grain boundaries between crystalline domains and crystallographic defect also have negative influence on charge transport. Therefore, increasing morphological ordering is the key point to enhance charge carrier mobility. Highly ordering morphology easily lead to delocalized electronic structure. Charge carrier would transport along the backbone of conducting polymer, which is more efficient than hopping.
In the study, we introduce sandwich process to align Poly(3-hexylthiophene) (P3HT). The uniaxial flow and nanogrooves help polymer crystalize orientationally. Furthermore, increasing process temperature could promote disentanglement of polymer chain. The extended P3HT is more easily aligned by SAM-treated substrate.
Molecular ordering is examined by AFM and Raman spectroscopy. The charge-carrier mobility is calculated by I-V characterization. Our results provide the high correlation between microscale molecular ordering and macroscale charge transport behavior.

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[55] 錢仕賢（2019）。探討噻吩與聯噻吩架構共軛高分子之有序形貌排列:聚(3-己烷噻吩) 及Poly(3,6-dialkylthieno[3,2-b]thiophene-co-bithiophene)。國立成功大學材料科學及工程學系碩士論文，台南市。 取自https://hdl.handle.net/11296/cnp9x8