本論文研究導入光致變材料對五苯環電晶體的光電效應影響，以高介電常數的氧化鋁搭配聚乙烯基苯酚(poly(4-vinylphenol), PVP)作為介電層、五苯環作為主動層，並在PVP中摻雜光致變材料spiropyran (SP)，製作低操作電壓的有機薄膜電晶體，且引入氧電漿處理主動層以優化電晶體性能。
利用吸收光譜、光激螢光光譜、x-ray繞射、表面能、化學分析電子光譜對混摻不同SP比例的PVP薄膜和半導體層進行特性分析，並研究元件電特性對紫外光與可見光的響應。未混摻SP的參考組元件對紫外光幾乎不產生反應，在可見光照射下則會使臨界電壓提前、次臨界擺幅上升，歸因於五苯環的吸收範圍位在可見光波段；而當元件導入SP後則能感測紫外光，且由光感測分析顯示紫外光照射下具激子與偶極矩的效應，相較於可見光環境下則只會有激子的影響，可藉由兩者的不同達到分辨紫外光與可見光的功能。導入SP的五苯環電晶體相較於可見光，對紫外光有較佳光響應，透過氧電漿處理主動層後使電性提升，光響應值增加30倍，並且具有明顯的記憶效應。綜上所述，導入SP之五苯環電晶體具有優異的紫外光感測能力，具有開發紫外光檢測的潛力。

In this study, we investigated the photoelectric effects of pentacene-based organic thin film transistors (OTFTs) with a photochromic material, namely, spiropyran (SP), in the gate dielectric layer. We fabricated low operating voltage OTFTs, in which high-k aluminum oxide (AlOx) combined with SP containing poly(4-vinylphenol) (PVP) was used as hybrid gate dielectrics, and pentacene was used as an active layer. Irradiation-induced structural changes between SP and merocyanine (MR) in the PVP layer were studied. Results revealed a MR structure in the PVP layer that could be successfully converted to the SP form under ultraviolet (UV) or visible irradiation and back again to the MR in the dark. The electrical characteristics of the corresponding OTFTs with PVP/SP buffer layer also showed significant changes upon UV light irradiation; these characteristics differed from those upon visible light irradiation. Compared with visible light irradiation, the present OTFTs with SP acquired superior photoresponse under UV light irradiation. This difference allowed the present OTFTs to distinguish UV and visible lights. The possible origins were further discussed. After oxygen plasma treatment on the active layer, which was used to improve the performance, the devices showed a remarkable memory effect. Consequently, the pentacene-based OTFTs with SP exhibited excellent ability to sense UV light and demonstrated strong potential use for photodetectors.

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