以金屬氧化物為通道的薄膜電晶體因其高載子遷移率、均勻性、可在較低溫下成長等特性，除了應用於軟性電子或是顯示器領域皆具有相當高的潛力外，也可以當作光電晶體，不同於光二極體，其具有高響應度與靈敏度，因此不用額外搭配CMOS放大電路。本篇論文使用高介電系數材料二氧化鉿來作為元件之閘極絕緣層以降低元件之操作電壓，以氧化銦鋅錫作為主動層，因其具有比氧化銦鎵鋅更高的載子遷移率，但少了鎵元素來抑制材料中的氧空缺且錫與氧的鍵結不像鎵與氧那麼強，這些都會導致漏電流的上升，因此本碩論第一部分將透過調變元件結構與製程環境來降低元件漏電流。
因受限於材料特性，金屬氧化物光感測薄膜電晶體只能應用於紫外波段且具有嚴重的延遲光電流問題，本碩論第二部分將搭配SubPc作為元件之有機吸光層，使其應用波段拓展至可見光，並藉著主動層與吸光層兩者材料間的能隙差來改善延遲光電流問題，大幅地提高元件的應用性。

Amorphous Oxide Semiconductor (AOS) materials have several advantages such as high mobility, great uniformity, low fabrication. In addition to having a high potential to be applied in flexible electronics or displays, it can also be used as a photo sensor. It is different from the photodiode, the metal oxide thin-film transistor based phototransistor (photo-TFT) has high responsivity and sensitivity, so there is no need for additional CMOS amplifier circuit. The photo-TFT was fabricatied with the high dieletric constant (high-k) gate insulator of HfO2 to reduce the operating voltage. And then in oder to pursue high mobility, InZnSnO (IZTO) was introduced as the active layer, because IZTO-TFT has higher mobility than IGZO-TFT. However, the lack of gallium element suppresses the oxygen vacancy in the material, and the bond between tin and oxygen is not as strong as gallium and oxygen. These will lead to leakage current. Therefore, we first adjusted the device structure and process environment to reduce leakage current.
Due to material characteristics, the metal oxide photo-TFT can only be applied in the ultraviolet band and have serious Persistent photocurrent (PPC) problems. Therefore, we used SubPC as the organic light-absorbing layer to extend its application band to visible light, and use the energy gap difference between the active layer and the light-absorbing layer to improve the PPC problem, which greatly improves the applicability of the device .

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