本論文利用脈衝雷射蒸鍍法(pulsed laser deposition,PLD)於C面Sapphire (0001)基板上,先蒸鍍ZnO緩衝層,再用MgXZn1-XO (0.0244≦x≦0.5) 的靶材成長奈米結構。再有系統地探討其成長參數對MgXZn1-XO奈米結構及光學特性的影響。當摻雜的鎂離子增加時,發現會讓MgXZn1-XO合金的晶格常數c軸縮短。且從X-ray diffraction (XRD)量測中,若未出現除(002)峰之外的其他峰位,即無相分離的情況,表示MgXZn1-XO合金具有很強的擇優取向和較好的晶體結構。由光激螢光光譜(photoluminescence,PL)量測,得知在摻雜的鎂離子增加時,可使紫外線Peak藍移,同時證實鎂離子掺入氧化鋅晶體中而且成功的佔據鋅離子的晶格位置,所以可藉著改變x值來控制發光的能隙。另外全高半寬(full zidth at half maximum,FWHM)卻也跟著變寬,推斷是因為摻雜鎂離子使得晶格排列不整齊或者一些應力的不平均,造成能帶放光變寬。除此之外,由掃瞄式電子顯微鏡(scanning electron microscope,SEM)及光激螢光光譜可知,多了ZnO緩衝層可使鎂離子的摻雜量增加及奈米結構密度增加。
MgxZn1-xO nanords are a key material for UV optoelectronic applications due to the tunable x-dependent bandgap energy. We had shown that MgZnO nanords can be synthesized by pulsed laser deposition (PLD) under relatively high-pressure conditions. In this study, in an attempt to improve the properties of MgZnO nanorods,a ZnO buffer layer was grown on the c-plane sapphire substrate brfore the nanorod growth. We found that the inserted ZnO layer, which reduces the lattice mismatch between the deposit and the substrate, resulted in the enhancement of the Mg incorporation and the density of the nanords. The effects of the growth parameters on the morphology, composition, and optical properties of the synthesized MgZnO nanostructures were systematically investigated.