五苯環素空間電荷侷限電晶體

Abstract

在本研究中，我們開發一種全新的垂直式空間電荷侷限電晶體。首先我們將探討五苯環素在垂直結構上的載子遷移率。我們利用紫外光對黃金的表面進行表面改質。根據觀察以及文獻的討論，得知經過紫外光改質後的黃金表面，金屬功函數會上升、表面能變大，進而提升五苯環素的載子遷移率。我們利用原子力顯微鏡來觀察五苯環素在黃金經過改質前跟改質後的差異性。另外我們也觀察五苯環素的蒸鍍速率對載子遷移率的影響，並利用X光繞射儀跟原子力顯微鏡來分析。我們將比較不同的載子遷移率對頻率響應的關係，並驗證出較快載子遷移率的操作頻寬確實較大。 接著我們利用聚苯乙烯奈米球狀物體當作奈米等級遮罩，製作出網狀的電極結構，以及利用先前得到的最佳化結果蒸鍍上五苯環素，製作出空間電荷侷限電晶體。我們得到了操作在一伏特內的電晶體，並且從製作的過程中，利用原子力顯微鏡以及掃描式電子顯微鏡來觀察一些製作上會碰到的問題，包括遮罩的陰影效應以及奈米球分佈性不佳造成的一些影響，還有主動層材料本身結晶性使電極間距過近造成的問題。

In this study, we developed a new vertical transistor and called space-charge limited transistors. Firstly, we discussed the pentacene carrier mobility in the vertical structure. The gold surface is modified by exposed ultraviolet light for several mins. According to our observation, after UV-treated gold surface, the work function of gold surface will be increased, the surface energy will be increased, and pentacene mobility will be improved, too. We used atomic force microscope to observe the pentacene molecular on gold with or without the UV treatment. In addition, we also observed the influence of pentacene deposition rate and mobility by used X-ray Diffractometer and atomic force microscope. Then, we demonstrated that the carrier will influence the bandwidth of frequency response. We used the polystyrene spheres as nano-scale mask to produce a mesh of the electrode structure, and we used the best previous results of pentacene evaporation to fabricate the space charge limited transistor. Therefore, we got a one volt operation voltage. However, we found some issues, such as the shadow effect of polystyrene spheres mask, the impact by nonuniform distribution of spheres, and the crystallization of active layer material itself so that the electrode spacing will be too close by using atomic force microscope and scanning electron microscope.