本論文以五環素(Pentacene)為主動層的有機薄膜電晶體中，探討使用摻雜注入層於有機主動層與源極/汲極之間的接觸效應，並且研究其對元件特性改善之效果。我們選擇使用上接觸式結構來研究摻雜注入層對元件特性的改善。首先我們把F4TCNQ與Pentacene以不同比例摻雜，發現F4TCNQ與Pentacene摻雜比例為1:1時為最佳化摻雜濃度。接著調變不同厚度的摻雜注入層，使其厚度參數也最佳化。由於接觸電阻與通道的長度無關，我們可以藉由線性區電流電壓和通道長度的關係，利用傳輸線模型(Transmission line model)萃取出接觸電阻，並且證明了加入摻雜注入層的元件特性之所以提升，是由於接觸電阻經由加入摻雜型注入層後而有效地降低了。
我們以不同金屬做為有機薄膜電晶體的源極/汲極，研究電極功函數的差異對元件電性的影響，得到了在加入摻雜注入層後的元件就算搭配了較低功函數的金屬，也可以得到不錯的特性。

The thesis discusses the contact effect of the interface between organic semiconductor layers and metal source/drain (S/D) electrodes on performance improvement of pentacene-based organic thin-film transistors (OTFTs), which uses top-contact (TC) structure and the p-doped injection layer at the pentacene/metal electrodes interface. First, we employed F4TCNQ doped pentacene with different doping ratio as injection layer. The best performance can be observed in which the doping ratio of F4TCNQ to pentacene is 1:1. Furthermore, we changed the thickness of injection layer to optimize the thickness for better performance. We extracted contact resistance of OTFT devices by Transmission line model, and we found the performance of device was improved as the contact resistance was decreased due to the p-doped injection layer.
In addition, we fabricated organic thin-film transistors using different metals as source and drain electrode to discuss the effect of work function of metal electrodes on performance of OTFTs. We found that good performance can still be observed in which the OTFTs use the lower work function metal and the injection layer at the same time, as compared with the OTFTs using Au electrodes without injection layer.

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