基于氧化铝模板的有序ZnO纳米棒的合成及光学特性研究

Synthesis and optical property research of well-ordered ZnO nanorods arrays based on Al_2O_3 membrane

利用高度有序的多孔氧化铝膜作为模板,使用简单的热蒸发Zn粉的方法,成功地制备出高度有序的ZnO纳米棒束,该方法克服了制备有序纳米结构通常需要的催化剂或复杂的合成过程。利用扫描电镜、透射电镜和X射线衍射研究了样品的形貌及其结构特性,其结果表明模板表面所制备的ZnO纳米棒具有更好的有序度和结晶质量,从而推断出模板表面有序ZnO纳米棒的形成应该同模板表面局域化负电荷的存在有关。同Si基片上所形成无序纳米棒的光致发光谱相比,模板表面所形成的有序ZnO纳米棒束具有更强的紫外峰,表明有序的ZnO纳米棒具有更好的结晶质量和光学特性。

Ordered ZnO nanorod arrays have been successfully deposited on top of well-ordered Al2O3 membrane by thermal evaporation of Zn powder,which overcomes the use of catalyst or complicated procedure during the formation process of aligned ZnO nanorods. The morphology and structural properties of prepared samples were studied by Scanning electron microscope, transmission electron microscope and X-ray diffraction. The experimental results indicate that ZnO nanorods on top of membrane have better crystal quality and ordering degree,suggesting that the formation of well-ordered nanorods should be related to the existence of negative charges localized on the surface of membrane. Compared with the photoluminescence spectrum of disordered ZnO nanorods deposited on the Si substrate,the ordered ZnO nanorod arrays formed on top of Al2O3 membrane display stronger ultraviolet peak, which suggests further that aligned ZnO nanorods have better crystal quality and optical properties.