本論文中首先嘗試製作且分析有機高分子絕緣層的平整度、漏電流、及介電常數，以期找出合適的絕緣層材料製作有機薄膜電晶體。分析後我們決定使用純PVP和純PI當作絕緣層材料，並且為了提高介電常數來幫助降低操作電壓，我們分別在PVP和PI兩種材料中摻雜適量的二氧化鈦奈米粉體，研究後發現此種有機/無機複合高分子材料的絕緣層單位面積電容皆上升，且介電常數可以提升10% ~ 26%。同時我們選擇以熱蒸鍍的方式成長五環素(pentacene)當做主動層，我們嘗試在四種絕緣層上改變蒸鍍速率及基板溫度成長主動層，實驗中我們利用XRD分析來計算各種情況下薄膜相與塊體相的比例，同時使用SEM或AFM來觀察晶粒大小及表面形貌。我們成功製作上接觸式元件和下接觸式元件此兩種結構的有機薄膜電晶體，最後可以發現在摻雜TiO2的絕緣層上製作的下接觸式元件，載子遷移率提升2~3倍，而上接觸式元件提升約2倍，PI+TiO2上可以獲得最佳的載子遷移率0.59 cm2/Vs，PVP+TiO2上載子遷移率0.53 cm2/Vs，而開關電流比和次臨界擺幅也獲得改善。

We try to examine characteristics of the dielectric layer and fabricate organic thin-film transistors by evaporating pentacene onto two different neat polymer dielectrics: PVP, PI and two composite polymer dielectrics: PVP+TiO2, PI+TiO2. The composite polymer dielectric has been designed in view to combine low voltage operating devices, by the use of High-k TiO2 which increases the charge in the accumulation channel and the gate capacitance, and highly stable devices which generally could be achieved with polymer dielectrics. We find that TiO2 has a significant effect, with measured mobility in Bottom-contact device ranging from between 0.007 and 0.027 cm2/Vs and in Top-contact device ranging from between 0.28 and 0.59 cm2/Vs. This variation appears uncorrelated with either the polymer surface morphology or the observed grain size. The higher mobility of TC OTFT on polymer dielectric is attributed to the lower contact resistance. The distribution of mobility, threshold voltage, on/off ratio, and subthreshold swing observed for each of the polymer dielectrics is presented.

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