Field emission is a quantum-mechanical phenomenon which electrons tunneling from a condense matter to vacuum under an external electric filed. Due to the characters of high current density, small energy distribution, and no energy consumption during the emission process, field emission devices are widely used in vacuum microelectronics including field-emission-display, high power RF amplifier, electron sources, and nanolithography.
Generally speaking, emitters with a lower work function will result in a higher emission current density. Although gold has a relatively high work function of 5.1 eV, with good conductivity and physical and chemical stability in high current operation, gold is still a promising candidate for field emitter material and a suitable system for investigating the fundamental essence of field emission. Both the field emission properties of single gold nanowire and whole chip of gold nanowires were measured. Simulations based on finite element method were carried out to investigate the screening effect, and aspect ratio effect on the field emission properties.
In the second part, field emission properties of gold in gallium oxide core shell nanowires were also investigated. The existence of a 10 nm layer of Ga3O on the tip of nanowire was observed, which resulted in a remarkable enhancement of field emission properties.

　　電子於外加電場下由凝態物質穿隧至真空中之量子力學現象稱為場發射現象。由於其高電流密度、能量分佈集中以及穿隧過程不需消耗能量之特色，場發射元件被廣泛的運用在真空微電子元件中，如高工率射頻放大器、電子發射源、奈米微影技術以及場發射顯示器中。
　　一般而言，為得到較高的發射電流密度，發射源一般選取擁有較低之功函數材料。金雖然有較高之功函數，但是由於其極佳導電性、化學和物理穩定性，仍被視為極佳之場發射源之製作材料之一。在本研究中，我們對大面積以及單根金奈米線之場發射特性進行量測。並且藉由有限元素分析法之模擬，探討屏蔽效應及高寬必對於場發射性質的影響。
　　在第二部份中，我們量測並對氧化鎵包金之場發射行為進行了探討。在實驗中，觀測到奈米線頂端存在一層10奈米之氧化三鎵。此一氧化三鎵之存在，能大幅提昇此一奈米結構之場發射特性。

Chapter 1
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Chapter 2
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Chapter 4
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