本研究以熱蒸鍍法利用三氧化鎢粉末做為前驅物搭配大流量載流氣體在矽基板合成W18O49奈米線，並搭配田口品質工程使製程參數最佳化，進而分析各參數對奈米線成長的影響；根據眾多文獻以及本研究結構分析結果，確認此奈米線成長機制應為汽相‒固相(vapor – solid, V-S)成長機制，利用氧化鎢蒸汽直接在目標基板上沉積成核形成奈米線；本研究亦嘗試摻雜鉬元素於氧化鎢奈米線內，依TEM分析結果表示，鉬元素以鉬鎢元素比1：7均勻分布於奈米線內；比較有無摻雜鉬的奈米線電組係數值，無摻雜的奈米線電阻係數值為2.32 x 10-5 m-Ω，而具鉬摻雜的奈米線電阻係數值為3.76 x 10-4 m-Ω，兩者皆優於文獻值，提高氧原子空缺濃度能夠增加電子傳導性質，而鉬原子屬於間隙型摻雜，會阻礙電子傳導。本研究亦將氧化鎢奈米線成長在ITO透明玻璃基板上，以製作電致變色元件，經測試後發現有優秀的循環壽命以及快速的反應變色速度。

In this study, oxygen-vacancy-rich tungsten oxide nanowires with high aspect ratio of around 700 were successfully synthesized on (100) Si wafer and ITO glass substrate via thermal evaporation without any catalyst. The growth mechanism of the nanowires was vapor-solid (VS) mechanism and TEM studies show that they were WO3-x nanowires with rich oxygen vacancies. We also tried to dope molybdenum into WO3-x nanowires to change relative properties. TEM and EDS studies show that Mo atoms were homogeneously distributed in the WO3-xnanowires and that the atom ratio of W and Mo was about 7 : 1. To explore and compare electrical properties, we designed an approach to measure a single nanowire resistivity. The resistivities of WO3-x nanowire and Mo-doped one at 300K were 2.32 x 10-5 Ω-m and 3.76 x 10-4 Ω-m, respectively; both were very low because of rich oxygen vacancies, but Mo atoms were interstitial doping in nanowires which may impede electron motion. We assembled electrochromic devices with LiClO4/ PC as the electrolyte and WO3-x nanowires-based ITO glass substrates. The devices possessed fast coloring and bleaching rate of less than a second at low voltage, while at high voltage, they could change to deeper colors; the devices were of great cycle times and response time. These significant results make WO3-x nanowires a promising material for applications in display and green technology.

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