本論文主要探討低操作電壓下之五環素(pentacene)電晶體於不同氣體環境下電特性的改變，以及其產生之記憶效應的研究。以玻璃作為基板、氧化鋁絕緣層及交聯的聚(4-乙烯基苯酚)作為介電修飾層，小分子有機材料五環素作為主動層製作低操作電壓的電晶體元件。
本研究大致分成兩個部份，第一部份將電晶體元件置於不同氣體環境（真空、氮氣、水氣、氨水蒸氣、醋酸蒸氣、乙醇蒸氣）下量測電特性，於氮氣、醋酸蒸氣、乙醇蒸氣環境下，元件電性幾乎沒有變化，可穩定進行操作，但放置於水氣下(相對溼度> 40%)，元件擁有較大的通道電流，且轉換特性曲線有順時針方向的遲滯，與多數論文中所提及之水氣會使有機薄膜電晶體通道電流下降的現象相反；而將元件置於氨水蒸氣的環境下進行電性量測時，可發現元件的通道電流持續下降、臨界電壓逐漸向負方向偏移，且轉換特性曲線遲滯方向上改變為逆時針，此現象與水氣下量測的元件電性有明顯的差異，因而此元件可藉由這些特性輕易地分辨水氣與氨水蒸氣兩種氣體。
另外，當元件置於氮氣下進行記憶體(memory)電性量測時，沒有辦法使用電壓寫入或清除載子，而通過氨水蒸氣的元件在大氣下量測則有明顯的記憶效應，並可藉由給予閘極瞬間的脈衝電壓-3.5 V來寫入，使用紅光雷射(λ = 633 nm)照射主動層進行清除，或可給予閘極-5 V的瞬間脈衝電壓，進行清除，且皆能比初始的臨界電壓更往正的方向偏移，而獲得更大的記憶窗口(1.2 V)。
綜合上述，本研究所製作之低操作電壓五環素電晶體可於醋酸蒸氣、乙醇蒸氣環境中穩定操作，並能分辨水氣與氨水蒸氣，於氨水蒸氣影響後於大氣中進行操作時，同時具備記憶體的功能，可藉由給予瞬間電壓或照射紅光的方式進行清除。

In this study, the electrical characteristics and memory effects of low-voltage-driven pentacene transistors in different atmospheres, including vacuum, nitrogen, water vapor, ammonia vapor, acetic acid vapor, and ethanol vapor, were investigated. We observed that the electrical properties of devices were almost unchanged under nitrogen, acetic acid vapor, and ethanol vapor environments. However, in the water vapor environment, the devices showed an increased output current with an increasing relative humidity and exhibited counterclockwise hysteresis in the transfer curves. This result was attributed to an increased polarization effect of the gate dielectric due to polar water molecules penetrating the interface between the gate dielectric and the active layer, thus creating a built-in electric field by applying gate bias. By contrast, inferior electrical characteristics associated with counterclockwise hysteresis in the transfer curves were observed when the devices were operated in the ammonia vapor environment. Therefore, we deduced that the presence of ammonia increased the trap density in the active channel of devices.
The influences of different environments on the electrical memory effects of the pentacene transistors were also analyzed. Results revealed that the ions dissociated from ammonia could make the devices produce the electrical memory effect. Charges could be written into the devices by providing a pulse voltage of −3.5 V to the gate and could be erased via red laser (wavelength of 633 nm) illumination. Moreover, the erasing process of the devices could also be achieved by providing a pulse gate voltage of −5 V for 1 s. The pentacene transistors in the ammonia atmosphere could perform a memory window of 1.2 V.
In summary, the pentacene transistors could be used as humidity and ammonia sensors that can clearly distinguish water from ammonia. In addition, the pentacene transistors could be used as memory devices after exposure to ammonia.

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