氧化鋅材料因為具有直接能隙、大的激子束縛能、無毒、低價等特性，所以被視為有潛力的光電元件材料。本論文分成四個部分，分別討論一維和二維的氧化鋅奈米結構的紫外光和氣體感測器特性。
首先，我們研究氧化鋅奈米柱的長徑比對紫外光感測器有甚麼影響。在此之前，氧化鋅奈米柱被製作成許多的元件，如場效電晶體、感測器等，但沒有對氧化鋅奈米柱的長度和寬度對薄膜式元件的特性影響程度作研究。因此我們藉由水熱法控制不同的成長濃度和成長時間製作不同長徑比的奈米柱，並將其應用於紫外光感測器，探討奈米柱對元件的影響程度。實驗的分析結果顯示，在濃度為0.05 M，成長時間為1.5小時的條件下，氧化鋅奈米柱紫外光感測器有最大的紫外光對可見光的拒斥比，約為56833。
氧化鋅材料本身很容易形成氧空缺，對元件來說，會有一個漏電路徑，造成電流的上升。因此，我們提出一個簡單的辦法來解決此問題，此方式是用APTMS來修飾氧化鋅表面，經過APTMS的修飾後，可以發現電流有明顯的下降，藉由XPS的分析，氧空缺的確都消失，連表面的汙染物都被移除了。除了薄膜，我們也用APTMS修飾奈米柱結構，但在電性方面只有輕微的下降，這是因為APTMS在奈米柱表面形成不同的化學鍵結(O–Si–O/Si–OH和O-Si-O)，且氧空缺無法完全的移除，所以才會導致此情形發生。我們是第一個藉由此方式應用於感測器上。
接下來，我們將奈米柱紫外光感測器製作在可撓基板上。此感測器光暗電流比可達到1.74 103，響應拒斥比達到95。而在不同曲率半徑下，發現在曲率半徑0.2公分的情況下光暗電流表現無明顯差異，電流在同一數量級內些微下降，表示在不同撓曲半徑下仍有很高的穩定性。最後我們也研究元件在不同光功率下的光電流及光增益改變，以及時間反應和雜訊等表現。元件的雜訊等效功率和檢測度為1.72 10-11 W 和 3.08 1011 cmHz0.5W-1。
一般來說，成長一維和二維的氧化鋅奈米結構都需要先在基板上鍍金屬顆粒或是沉積一層種子層，藉由氣-液-固法或是相似的晶格結構成長奈米結構，且需要較昂貴的機台和高溫成長方式。因此，使用一個新穎製程，以製程簡單、快速、便宜、較低溫的奈米結構製程方式有意義的。經過無數次的實驗，我們成功利用爐管在玻璃基板上合成出奈米牆結構，且無使用金屬觸媒或是種子層。在450度C，氧氣/氮氣比為10/200 sccm，製程壓力維持20 torr，製作出良好品質的氧化鋅奈米牆。接著將其製作成紫外光和氣體感測器，氧化鋅奈米牆的紫外光感測器對紫外光敏感、有很快的反應速度，在雜訊方面也有不錯的特性。雜訊等效功率和檢測度分為1.87 10-10 W 和 3.38 109 cm•Hz0.5•W-1。而在氣體感測器方面，對甲烷有較高的反應，且有著不錯的反應速度。我們用此方式做出的奈米牆感測器都有不錯的特性，甚至比別的團隊製作出的元件特性來的要好。

Due to direct band gap, large exciton binding energy, non-toxic, low price, ZnO-based semiconductors have been regarded as one of the potential materials for optoelectronic devices. The dissertation can be divided into four parts, and separately discuss the fabrication and optoelectronic of one- and two-dimensional ZnO nanostructure devices.
In first study, various aspect ratio (length divided to diameter) of NR are synthesized by hydrothermal method and applied at ZnO MSM UV sensor. Before that no study evidence the aspect ratio of ZnO NR whether affects the I-V characteristics of ZnO NR UV sensor or not. Therefore, various growth concentration and growth time can change the aspect ratios of NR. UV sensor with ZnO NR grown by aqueous concentration of 0.05 M and growth time of 1.5 h has the best I-V characteristic than others. The UV-to-visible rejection ratio is about 56833.
As we know, ZnO eases to form oxygen vacancy, which could cause a leakage current path for ZnO device. Therefore, a simple surface treatment process is developed for improving its surface defects. We immerse the ZnO film and NR UV sensor into the 3-aminopropyltrimethoxysilane (APTMS). The APTMS-modified ZnO film UV sensor has lower dark current than that without modification. According to the XPS spectra, the ZnO film before and after APTMS-modified have different bonds. From O 1s and C 1s core level spectra, it can be known that the oxygen vacancy and surface contamination of ZnO could be modified by APTMS. Therefore, APTMS molecule is a good material to modify the surface of ZnO. The APTMS-modified ZnO NR UV sensor has lightly lower dark current than ZnO NR sensor without modification. According to the XPS spectra, oxygen vacancy can not be modified totally, and can be found it has O–Si–O/Si–OH and O-Si-O bond. The both reasons cause the I-V characteristics of ZnO NR sensor with APTMS-modified could not be improved too much.
The third thesis discusses the study of ZnO NR UV sensor prepared on flexible substrate. The ZnO NRs are grown by hydrothermal method with low temperature. The ZnO NR sensor can have lower dark current and larger UV-to-visible rejection ratio than ZnO film sensor. The Iphoto / Idark ratio of ZnO NR sensor can reach 1.74 103 and the UV-to-visible rejection ratio of ZnO NR sensor is 95. I-V and responsivity characteristics of the flexible device under bending are also measured. There is no more than one order difference in dark current and responsivity when the device is bended from plane to 0.2 cm radius of curvature and this result shows that our device has high stability under bending. Finally, the photocurrents and photoconductive gains under various UV intensities, the photoresponse, and the noise characteristics of the device are performed. The noise equivalent power and the detectivity of ZnO NR UV sensor are 1.72 10-11 W and 3.08 1011 cmHz0.5W-1, respectively.
As we know, the one- and two-dimensional ZnO nanostructures must deposit a metal-catalyst or a seed layer on the substrate before synthesizing ZnO nanostructures, and mostly have to use expensive machine and high growth temperature. Therefore, developing a simple, low cost, rapid, catalyst-free, non-toxic, and low-temperature process to synthesize ZnO nanostructures is meaningful. In this thesis, ZnO nanowalls-film directly grows on a glass substrate without catalyst or seed layers by furnace. After analysis of the experimental results, the ZnO nanowalls-film could be synthesized at 450 ℃ with O2/N2 gas ratio of 10/200 sccm and growth pressure of 20 torr. Then, a UV sensor and a gas sensor are fabricated on ZnO nanowalls-film using an interdigital metal mask. The ZnO nanowalls-film shows a strong UV emission and a preferred c-axis orientation with a hexagonal structure. The measurement of the ZnO nanowalls-film UV sensor shows a high sensitivity to UV light, rapid rise and decay time, a good UV-to-visible rejection ratio, and a good flicker noise characteristic. This shows the strong potential of ZnO nanowalls-film for using in UV sensor. At an applied bias of 2 V, the noise equivalent power and the normalized detectivity of the ZnO nanowalls-film UV sensor are 1.87 10-10 W and 3.38 109 cm•Hz0.5•W-1, respectively. Measurements of methane sensor show a high sensitivity to methane gas, and rapid response and recovery time. These unique characteristics are attributed to the high surface-to-volume ratio of the ZnO nanowalls. Thus, the ZnO nanowalls-film is a potential candidate as a methane gas sensor owing to its good performance. The characteristics of ZnO nanowalls-film devices are better than other literatures.

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