在矽基板上以電漿輔助式分子束磊晶法成長氧化鋅奈米柱的特性分析

Abstract

本篇論文主旨在矽基板上利用氮化鋁作為緩衝層能成功地以電漿輔助式分子束磊晶法成長出自組成氧化鋅奈米柱與氧化鎂鋅/氧化鋅奈米柱。掃描式電子顯微鏡影像與X光繞射分析顯示，當鋅流量由8.53×10-8 Torr增加至1.72×10-7 Torr時，氧化鋅逐漸形成六角形貌。且隨著氧化鋅成長時間增加，氧化鋅傾向沿著垂直基板的方向上成長而形成奈米柱。此外，當氧化鎂鋅成長在氧化鋅奈米柱上時，依然維持六角柱形貌與c軸為成長取向，能量散射光譜儀顯示在氧化鎂鋅/氧化鋅奈米柱內的鎂含量約為7~8%且並不隨奈米柱直徑大小而改變。低溫螢光光譜顯示氧化鎂鋅/氧化鋅奈米柱與氧化鋅奈米柱具有強近能隙發光且無氧空缺所導致的缺陷發光。由本論文的結果說明能製備高品質的氧化鋅奈米柱與氧化鎂鋅/氧化鋅奈米柱，並且有潛力應用在光電元件上。

Self-assembled ZnO and ZnMgO/ZnO nanorods were grown by plasma assisted molecular beam epitaxy on Si(111) substrates with an AlN buffer layer. The scanning electron microscopy and x-ray diffraction measurements revealed that the ZnO nanorods gradually formed a hexagonal shape by increasing Zn flux to 1.7×10-7Torr, and a c-axis preferred growth as the growth time increases. As ZnMgO were heteroepitaxial grown on ZnO nanorods, the hexagonal shape and the c-axis preferred orientation remained. The Mg concentration of 7~8 atomic% was observed by energy dispersive x-ray spectroscopy and independent of nanorods’ width. The low temperature photoluminescence spectra showed strong near band edge emission without deep level emissions for both ZnO and ZnMgO/ZnO nanorods. In this study, we demonstrated the growth of high quality ZnO and ZnMgO/ZnO nanorods which have potential for applications in optoelectronic devices.