本論文利用有機共軛高分子材料聚(3-己基噻吩) [poly(3-hexylthiophene), P3HT]與絕緣材料聚甲基丙烯酸甲酯[Poly(methyl methacrylate), PMMA]進行混摻做為電晶體的主動層，並於主動層上疊加N型材料N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13H27)或P型材料pentacene，加強電晶體主動層的載子傳輸能力，製作為多成分主動層的有機薄膜電晶體，再對元件進行電特性分析，以及探討元件感測特定波長的光之響應度變化。
第一部分，採用溶液製程製作不同重量比例P3HT/PMMA混摻主動層製作有機薄膜電晶體，選用氯仿與甲苯作為溶劑。首先，利用半導體分析儀(Keithley 4200)分析有機混摻薄膜電晶體之電特性，當溶劑為氯仿，P3HT:PMMA混摻比例為1:1，製作的電晶體元件有較佳電特性。
接著探討混摻薄膜之表面結構與特性，利用原子力顯微鏡(AFM)發現混摻薄膜為柱狀與網狀結構；以及利用導電式原子力顯微鏡(c-AFM)驗證P3HT形成連續的網狀結構，而PMMA形成不連續的島狀結構。最後將最佳製程條件的電晶體元件進行光感測分析，可觀察到元件對綠光(532 nm)的光響應度高於紅光(650 nm)，此與P3HT光吸收波段約在綠光波段有極大關聯性。
第二部分，延續最佳化有機混摻薄膜電晶體的製程條件，並在其混摻層作結構變化，以疊加P型材料pentacene或是N型材料PTCDI-C13H27的方式，製作為多成分薄膜電晶體，目的為提升電晶體元件感測光之響應度。首先以半導體分析儀分析電晶體的電特性，發現混摻層上疊加pentacene的電晶體能大幅提升元件之載子遷移率(Mobility)，歸因於P3HT與pentacene皆為P型材料，可提升元件的載子傳輸能力；而混摻層上疊加PTCDI-C13H27的電晶體會使元件導電性提高、閘極控制能力變差，導致元件關電流上升。而光感測部分，觀察到混摻層上疊加pentacene的電晶體能有效的提升元件的光響應度，但對比於混摻層疊加PTCDI-C13H27的電晶體其光響應度仍較差，歸因於PTCDI-C13H27對綠光有較強的吸收度，因此混摻層疊加PTCDI-C13H27的電晶體在小電壓下操作也能達到光感測效果。

In this study, we investigated the electrical and photoresponse properties of organic thin-film transistors (OTFTs) based on poly(3-hexylthiophene) (P3HT)/poly(methyl methacrylate) (PMMA) binary blends. P3HT/PMMA blend active layers with various compositions were prepared by spin-coating technique using chloroform and toluene solvents to obtain a specific phase-separated microstructure. Atom force microscope (AFM) and conductive-AFM techniques were used to obtain the morphology image of P3HT/PMMA blends and clarify the phase separation between P3HT and PMMA. OTFTs were investigated under dark and under illuminations with light wavelengths of 532 and 650 nm, and the effects of the microstructure of P3HT/PMMA blend active layer on the photoresponse of OTFTs were analyzed. Among the studied OTFTs, those with P3HT/PMMA blend (1:1, w/w) active layer made by chloroform solution show the best electrical and photoresponse properties. A maximum photoresponse of 0.17 under 13.92 mW/cm2 of 532 nm illumination is observed.
A 60 nm-thick top layer of N,N’-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13H27) or pentacene was thermally deposited onto the P3HT/PMMA blend films to obtain a multicomponent active layer and thus further enhance the photoresponse of the OTFTs. The corresponding photoresponse properties of OTFTs were studied. The P3HT/PMMA blend-based OTFTs with a N,N’-ditridecylperylene-3,4,9,10- tetracarboxylic diimide (PTCDI-C13H27) top layer demonstrate the highest performance with a maximum photoresponse of 1920 under 13.92 mW/cm2 of 532 nm illumination. The photoresponse of P3HT-based OTFTs increased by > 1000 times by blending with insulating PMMA and covering with an n-channel PTCDI-C13H27.

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