經由氮化鎵奈米線增強之氣體放電照明系統

gallium nitride nanowires enhanced gas discharge luminance system

廖子傑(Zi-Jie Liao)

指導教授 ： 蔡宗惠

大同大學/電機資訊學院/光電工程研究所/碩士(2010年)

摘要

本實驗主要利用氮化鎵奈米線整合於氣體放電照明系統中之電極。此作法有兩項優點：一、氮化鎵奈米線易產生電子場發射效應，使中性氣體電離率增加。二、鎵原子之殼層電子結構與汞原子相似，於氣體放電照明系統中，電漿解離之鎵離子能取代汞離子，增加電極間氣體放電時阻抗，以達到放電管之阻抗維持。
實驗中氮化鎵奈米線先是利用氣相-液相-固相之機制成長於矽基板，並利用掃描式電子顯微鏡分析氮化鎵奈米線之微觀結構、穿透式電子顯微鏡分析其內部結晶結構、能量分散X光譜儀分析其元素含量之後，我們將氮化鎵奈米線整合在氣體放電系統之電極上。當氣體放電照明系統使用具有此針狀之奈米結構，能有效使電子從電極表面發射使操作電壓有效的降低。經由電性之分析其輸入電流變化，相較於含有汞金屬照明系統之對照組，其操作功率明顯降低。藉由輸出光功率與輸入電功率之比值可得轉換效率。當電漿產生時，氮化鎵奈米線解離出鎵離子，可以有效捕捉游離電子以增加放電管之阻抗。我們利用光譜儀分析其氣體放電時所發出之光譜，進而了解系統內電漿釋放之元素。從光譜圖中可明顯觀察到具有鎵離子之光譜訊號。實驗組含有氮化鎵奈米線於電極上，其高亮度氣體放電照明系統之轉換效率明顯優於對照組。我們證明氮化鎵奈米線具有的奈米結構之電極可以達到降低啟動電壓，當電弧、電漿產生時，鎵離子可以由氮化鎵奈米線中釋放，以利維持放電管間的阻抗，達到驅動器效率的提升，皆因鎵金屬能有效取代汞金屬，而達節能環保之目的。

關鍵字

氣體放電照明 ； 奈米線 ； 氮化鎵

並列摘要

We produced a gas discharge luminance system which has gallium nitride nanowires embedded on electrodes. These nanostructures can enhance the field emission process to reduce plasma ignition voltages. Gallium has the atomic structure similar to mercury which can be used in the high intensity discharge luminance system to capture electrons in order to reduce electron bombardment at electrodes.
The gallium nitride nanowires grown on silicon substrates by vapor-liquid-solid(VLS) mechanism. Scanning electron microscope, tunneling electron microscope energy diffraction spectrum were employed to analysis their crystalline structure and forming elements. The results show that gallium nitride nanowires have wurzite structure, and the forming elements have oxygen, gallium and nitrogen. The exacter of gallium ion in plasma tube was confirmed by optical emission spectroscopy (OES). Compare to the conventional luminance system, the experimental system assistant by gallium nitride nanowires exhibits the lower input current. This gallium nitride nanowires embedded system improved power utility. By releasing gallium ions into the tube, it can replace the mercury in the system to improve the power consumption and created a environmental friendly lighting tool suitable for modern luminance device.

並列關鍵字

cold cathode fluorescent lamp ； high intensity discharge luminance ； gallium nitride nanowires

參考文獻

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