臺灣博碩士論文加值系統

本研究以水熱合成法研製複合金屬氧化結構之多孔性氣體微感測器，應用於醇類氣體的感測。本裝置利用待測氣體吸附於金屬氧化薄膜，使薄膜產生電阻值變化，藉量測電阻值變化獲得氣體微感測器的靈敏度。在不同操作溫度與不同的氣體濃度下，探討複合金屬氧化薄膜響應電阻值的變化與其回復性。利用水熱合成法(Hydrothermal Synthesis Method)製作氧化鋅/二氧化錫(ZnO-SnO2)粉末，以奈米花狀ZnO-SnO2金屬結合多孔性氧化鋁，完成新穎複合式奈米金屬氧化感測結構，並結合局部加熱裝置，提高氣體感測靈敏度。微製程以界面活性劑改善粉末團聚現象，獲得均勻奈米花狀分布結構，披覆於金屬氧化鋁層上，提高待測氣體與感測薄膜接觸面積，加速表面複合金屬氧化薄膜之化學反應，能加快反應時間與有效提升元件感測靈敏度，可應用於醇類氣體吸附之電阻性感測。

A compound sensing structure based on nanoflower-like zinc oxide (ZnO-SnO2) on the top of the nanoporous anodic aluminum oxide (AAO) layer is developed. The powder agglomeration phenomenon of microfabrication process was improved by using a surfactant to obtain uniform nanoflowers of ZnO-SnO2 as a sensing layer for detecting ethanol and methanol gases. The ZnO-SnO2 powders were synthesized using hydrothermal synthesis method. The crystalline phases and purity of the synthesized 3D hierarchical SnO2 nanostructures were analyzed using a X-ray powder diffraction (XRD) that illustrated diffraction patterns accord well with tetragonal rutile SnO2 of the JCPDS Card (no. 41-1445). The uniform nanorods of SnO2 formed unique loose and porous structures increase the accessible surface area of the materials to significantly improve gas diffusion and mass transport. A microheater was designed to control local temperature to promote gas sensitivity. The methanol response of the ZnO-SnO2-AAO structure is high because the porous AAO had improved greatly the specific adsorption surface area, and the ZnO produce more electron donor states or oxygen vacancies to enhance oxygen adsorption as well as the heterojunction of SnO2 and ZnO grains offers access to facile electronic interaction to enhance the surface reaction between adsorbed oxygen and current-carrying electrons. The developed ZnO-SnO2-AAO gas sensing structures include many advantages: simple fabrication process, low cost, high specific surface area, dense porosity, rapid detection, linear sensitivity, high stability, and good repeatability and reproducibility.

誌 謝 I
摘 要 II
Abstract III
目 錄 IV
圖目錄 VII
表目錄 X
第一章 緒論 1
1.1 前言 1
1.2 研究動機與目的 1
1.3 文獻探討 2
1.3.1 多孔性奈米材料與薄膜 2
1.3.2 氧化金屬結構之氣體感測器 5
1.4 研究方法與架構 6
第二章 感測薄膜製作與氣體感測器原理 7
2.1 多孔材料 7
2.2 陽極氧化鋁成長機制 7
2.2.1 初始孔洞成核 8
2.2.2 穩態成長 9
2.2.3 多孔性陽極氧化鋁製備方法 10
2.3 二氧化錫薄膜功能與應用 11
2.3.1 二氧化錫結構與特性 11
2.3.2 水熱法技術 12
2.3.3 二氧化錫之氣體感測特性與應用 13
2.4 摻雜機制 13
2.4.1 內部摻雜 14
2.4.2 表面摻雜 15
2.5 氣體感測器特性與功能 16
2.5.1 金屬氧化物氣體感測器 18
2.5.2 蕭特基接觸 18
2.5.3 半導體金屬氧化物氣體感測器特性 18
第三章 氣體感測薄膜製程設計 20
3.1 多孔性陽極氧化鋁製程規劃 20
3.1.1 陽極處理製程設備 20
3.1.2 陽極氧化鋁成長 20
3.1.3 氧化鋁移除 21
3.2 水熱法合成花狀氧化鋅/二氧化錫 21
3.2.1 水熱法合成二氧化錫粉末 21
3.2.2 氧化鋅修飾花狀二氧化錫粉末 22
3.3 氣體微感測結構設計 22
3.4 氣體量測架構設計 23
第四章 量測與分析 24
4.1 陽極氧化鋁成長分析 24
4.2 水熱法合成二氧化錫薄膜分析 26
4.2.1 水熱合成時間對二氧化錫成長之影響 26
4.2.2 水熱合成溫度對二氧化錫成長之影響 27
4.2.3 高分子材料CTAB對花狀二氧化錫之影響 28
4.2.4 氧化鋅修飾二氧化錫分析 30
4.2.5 二氧化錫結晶性分析 31
4.3 加熱器與感測電極分析 31
4.3.1 加熱器與感測電極製程 32
4.3.2 鎳鉻絲加熱器特性分析 32
4.3.3 感測電極與氣體感測元件整合 33
4.4 單氣體量測分析 34
4.4.1 甲醇氣體量測分析 35
4.4.2 乙醇氣體量測分析 37
4.4.3 異丙醇氣體量測分析 39
4.4.4 丙酮氣體量測分析 41
4.5 混合氣體選擇性分析 44
4.5.1 甲醇氣體與其他氣體混合分析 44
4.5.2 乙醇氣體與其他氣體混合分析 46
4.5.3 甲醇與乙醇氣體混合濃度變化分析 48
4.5.4 三種氣體混合之選擇性分析 50
4.5.5 四種氣體混合之選擇性分析 53
4.6 低濃度甲醇與乙醇氣體量測分析 54
4.7 氣體感測器改良 55
第五章 結論與未來展望 56
5.1 結論 56
5.2 未來展望 57
參考文獻 58

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