本論文研究不同氣體環境對五環素薄膜電晶體元件的電特性影響，氣體環境如氬氣、氮氣、氧氣、與飽和水氣環境，主要利用電場—極化分析與表面電位顯微鏡（Scanning Kelvin Probe Microscopy, SKPM）量測，探討不同氣體對有機元件之電性的影響機制。以真空環境下，元件表現出的電特性為基準，當操作於氬氣與氮氣環境下，元件的轉換與輸出電特性未有明顯改變；然而，當操作於水氣與氧氣環境下，元件的輸出電流則有大幅提升。利用阻抗量測金屬/絶綠體/金屬(MIM)二極體與金屬/絶綠體/半導體/金屬(MISM)二極體的電容特性，發現當元件操作在水氣的環境下，MISM元件較MIM元件表現出較高的電容值，電場—極化分析指出水氣可增益MISM元件內的極化電場，因此解釋了於水氣環境下，五環素薄膜電晶體元件有較佳的電特性。利用SKPM量測在不同氣氛下，銀源、汲極與五環素主動層間的表面位能差，發現在氧氣環境下，銀電極與五環素有最小的位能差，有助於載子於源汲極與主動層間的注入／取出效率，因此，五環素薄膜電晶體元件可表現出較佳的電特性。綜合而論，氬氣和氮氣環境對五環素薄膜電晶體的電特性並無明顯效應，而氧氣與水氣環境則對五環素薄膜電晶體的電特性有明顯的正效應。

In this study, we investigated the electrical characteristics of low-voltage-driven pentacene-based organic thin-film transistors (OTFTs) in vacuum, argon (Ar), nitrogen (N2), oxygen (O2), and water vapor environments. We explored the gas effects on the electrical characteristics of OTFTs by impedance analysis of the corresponding metal-insulator-semiconductor-metal (MISM) and metal-insulator-metal (MIM) devices and Scanning Kelvin Probe Microscopy (SKPM) measurements of the surface of devices. The observed electrical characteristics of OTFTs in Ar and N2 environments were similar to those obtained in the vacuum condition. However, the electrical characteristics of OTFTs in O2 and water vapor environments were considerably improved compared those in other conditions. Under saturated water vapor condition, the capacitance of MISM devices was higher than that of MIM devices with combined aluminum oxide and poly(4-vinylphenol) as the insulator. Under the same condition, the devices exhibited maximum electric-field polarization effects compared with those in other environments. This phenomenon improved the electrical characteristics of the OTFTs in saturated water vapor condition. SKPM analysis showed that the increased output current of OTFTs in the O2 gas condition was attributed to the decrease energy barrier between pentacene and silver electrodes. In summary, the positive effects of electrical characteristics of pentacene-based OTFTs were observed after exposure to O2 and water vapor.

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