本論文研究複合有機主動層之電晶體的光感測特性，先製作聚(3-己烷噻吩)/聚甲基丙烯酸甲酯 [poly(3-hexylthiophene)/ poly(methyl methacrylate), (P3HT/PMMA)]混摻物主動層，再於其上堆疊五環素(pentacene)或駢苯衍生物[N,N-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13H27)] ，分別使用二氧化矽或氧化铝當主要閘極介電層，探討不同色光照射下之有機電晶體的電特性與光感測效果。
第一部分，製作以二氧化矽當主介電層之P3HT/PMMA混摻主動層有機電晶體，研究主動層薄膜結構與對元件光感測特性的影響。原子力顯微鏡與靜電力顯微鏡揭示P3HT/PMMA混摻主動層具有特殊的柱狀相分離結構，PMMA形成柱狀結構，而P3HT形成連續地平坦結構。研究照光對元件電性的影響，當照射綠光與藍光時，會增加元件的關電流與次臨界擺幅，並使臨界電壓提前。光感測分析發現P3HT/PMMA薄膜電晶體之光感測能力優於純P3HT電晶體，歸因P3HT與PMMA界面可以幫助激子解離，產生帶電荷載子，因而提升光感測效果。
第二部分，沿用感測能力較佳之P3HT/PMMA薄膜電晶體，再於P3HT/PMMA混摻主動層上堆疊pentacene或PTCDI-C13H27製作複合薄膜電晶體，研究元件之電特性及光感測能力。電特性分析發現堆疊Pentacene於P3HT/PMMA混摻主動層上可以提升元件性能；而堆疊PTCDI-C13H27於P3HT/PMMA混摻主動層上則會使元件性能變差。光感測分析觀察到堆疊Pentacene的電晶體對於綠光的感測效果優於藍光，其歸因於pentacene的加入，增強了主動層對綠光波段的吸收；而堆疊PTCDI-C13H27的電晶體則對於藍光和綠光的感測效果差不多。光感測能力方面發現，堆疊Pentacene的電晶體因為受到場效電流影響較大而使得其於各色光下之光響應 R_(L/D)較P3HT/PMMA電晶體差，但堆疊PTCDI-C13H27的電晶體對於藍光和綠光之最大光響應R_(L/D)比P3HT/PMMA電晶體高出約200倍，歸因於其受到場效電流影響較小，且PTCDI-C13H27對光的吸收主要在藍光、綠光波段以及PN異質接面有助於激子解離，因此能有較佳之光感測能力。
第三部分，沿用先前堆疊PTCDI-C13H27之電晶體的元件架構，將主要閘極介電層二氧化矽改為氧化鋁，製成操作電壓只需-2.5 V之複合薄膜電晶體。進行光感測分析發現元件對於藍光與綠光之光感測效果相當，但對於紅光之光感測效果較差，歸因於複合薄膜在紅光波段的吸收較差且紅光的光子能量較低而導致。

In this study, we investigated the electrical characteristics and photoresponse properties of organic thin-film transistors (OTFTs) with a multicomponent organic active layer containing a bottom layer of poly(3-hexylthiophene):poly(methyl methacrylate) (P3HT:PMMA) blend and a top layer of pentacene or N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13H27). The P3HT/PMMA blend films were characterized by atom and electric force microscopy analyses. The blend films exhibit a phase-separated morphology consisting of columnar PMMA-rich phases and continuous P3HT-rich phases. Under blue (450 nm) and green (533 nm) light illumination, P3HT:PMMA blend-based OTFTs show a slight increase in the off current and subthreshold swing and a decrease in the threshold voltage. The photoresponse values of the P3HT:PMMA blend-based OTFTs are superior to those of the neat P3HT-based OTFTs. The photoresponse values of the P3HT:PMMA blend-based OTFTs with a PTCDI-C13H27 top layer also show a remarkable increase that is approximately 200-fold higher than that of OTFTs without a PTCDI-C13H27 top layer under blue and green light illumination. Results also demonstrate the high photoresponse of low voltage-driven OTFTs containing P3HT:PMMA blend/PTCDI-C13 hybrid active layer combined with a high-K aluminum oxide main gate dielectric layer.

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