我們使用X-ray光譜，原子力顯微鏡（AFM）來測量並分析利用分子束磊晶儀（MRE）成長的次微米pentacene薄膜；並在p-type矽基板上、室溫下製作以pentacene分子當作主動層的有機薄膜電晶體（organic thin-film transistors，簡稱OTFTs）元件。我們利用類似配向液晶的方式，以光配向polyimide來排列pentacene分子，可將元件載子遷移率提升至0.48～0.82㎝2/Vs。
實驗發現，分析元件通道中電流流動方向與pentacene排列方向間的關係，可得知電流垂直或平行pentacene分子排列方向的載子遷移率異向性比（anisotropic ratio of carrier mobility）約為2.7～8.3。
　　透過X-ray光譜分析，知道成長在PA-PI上的pentacene分子薄膜具有兩種結晶態「thin-film phase」和「single crystal phase」，由文獻上得知，若兩種結晶態同時存在pentacene分子薄膜中，其元件特性不佳，所以藉著最佳化照射於PA-PI膜的UV光能量，可使在其上成長的pentacene分子只存在一種結晶態，進而得到較佳的元件表現。

　　Pentacene films with submicron thickness, deposited by molecular beam deposition, were fabricated and characterized using X-ray diffraction, atomic force microscopy and Raman spectroscopy. Organic thin-film transistors (OTFTs) were fabricated on a p-type silicon substrate, using an active layer of highly ordered small pentacene molecules, being grown at room temperature. Pentacene film was aligned using the photoaligned polyimide method, which is usually employed to align liquid crystals. Improved field-effect mobility, in the range 0.48 – 0.82 cm2/Vs, was achieved in pentacene-based OTFTs with photoaligned polyimide layers, in which the pentacene molecules were aligned parallel to the direction of the transport of the carriers. The mobility was improved when the current flowed parallel or perpendicular to the orientation of the pentacene films with anisotropic ratios of 2.7 – 8.3.
　　The thin-film structures of pentacene on the photoaligned polyimide surface depend on the dose of UV light that irradiates on the polyimide surface. X-ray analyses reveal that the structure of the highly ordered pentacene films includes only a single “thin-film phase”, generated by optimizing the energy of irradiation of the photoaligned polyimide. However, the poorly aligned films include two phases- a “single-crystal phase” and a “thin-film phase”.

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