自我組裝的觀念是近年來備受注目的一種形成奈米尺度材料的方法。因為傳統的光學微影方法對合成奈米尺度的材料已經到了一定的瓶頸, 而自組裝,定義為自動的組織.組成結構而不需要任何人工介入,正是突破這個瓶頸的解決方法之一。此外,一維的奈米發光材料因其在發光元件的進程中所具有之獨特的功能及實用性,亦被廣泛的研究與討論。本篇論文將介紹以自組裝方法形成金顆粒網絡並進一步催化生成發深藍波段光的矽鍺氧奈米線以及其發光機制的探討。
金的奈米顆粒溶於甲苯溶液已經可以穩定的藉由兩相法合成。在合適的溫、溼度下, 將適量溶液滴在五公厘見方的矽鍺晶片上, 自組裝的金蜂巢狀結構便可形成。當我們將此晶片放到氮爐中退火至400 ℃ 並恆溫30 分鐘, 金的蜂巢狀結構開始改變, 金顆粒有向六個蜂巢節點聚集的趨勢。當我們繼續升高溫度至800 ℃ 並恆溫60 分鐘, 所有的金顆粒為了達到最低的表面能,全部都聚結在蜂巢的六角,於是自組裝的六角金顆粒網絡便成型了。
當我們將溫度進一步升溫至1075 ℃,並恆溫10分鐘, 火球狀的矽鍺氧奈米線便被金顆粒催化生成在六角金顆粒上。藉由穿透式電子顯微鏡的觀察及能量散佈光譜儀的分析,在金顆粒表面生成的矽鍺氧奈米線具有非晶質的結構。因為金顆粒直徑約有一微米, 此種結構的成長機制經研判為VLS 及OAG 同時作用。
陰極激發光譜(CL)顯示此種結構會激發出極強的深藍光,尖端波長位於418 nm 的位置。而藉由發光影像製圖,可以發現主要的發光位置和六角狀矽鍺氧奈米線所在的位置相符。換言之, 一個嶄新的自組裝六角發藍光陣列儼然形成。

Honeycomb structure of Au nanoparticles on Si0.8Ge0.2 was drop-cast from the Au nanoparticle solution. Hexagonal networks with discrete Au particles were generated in samples annealed in N2 ambient. For samples held at 1075 ℃ for 10 min, novel fireball-like Si1-xGex oxide nanowire networks were formed. From the transmission electron microscopy observation, the nanowires were found to vary in composition of Si, Ge, O, and to possess an amorphous structure. The growth of Si1-xGex oxide nanowires was proposed to be dominated by vapor-liquid-solid and oxide-assisted-growth mechanisms. Cathodoluminescence (CL) measurements show that the synthesized SixGe1-x oxide nanowires have a strong blue emission peak at 418 nm (2.99 eV ). According to the CL mapping image, it could be found that the main light-emitting positions coincide with the positions of the hexagonal SixGe1-x oxide nanowire networks.

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