中文摘要：

用一种混合方法用来制备ZnO纳米结构薄膜,首先利用射频磁控溅射法在玻璃衬底上沉积ZnO薄膜作为种子层,然后用水热方法合成ZnO纳米结构薄膜.为研究ZnO纳米结构薄膜的特性,利用X——射线衍射(XRD)及扫描电子显微镜(SEM)对薄膜的结构和形貌进行分析,并用X——光电子能谱技术(XPS)对薄膜的化学组份进行分析,最后利用光致发光方法(PL)对ZnO薄膜的发光性能进行了研究.从XRD谱图中可以看出,无论溅射的ZnO种子层还是水热合成ZnO纳米结构薄膜均为良好c轴(002)结晶状态的六角纤锌矿结构.从SEM图像看出,磁控溅射ZnO种子层为连续平整的膜状结构;而经过水热处理后则得到垂直于衬底的六角纳米棒和纳米片两种不同形貌的结构.XPS分析现示,在ZnO种子层中,锌和氧的比例基本上为1,说明磁控溅射ZnO晶体质量较好;而ZnO纳米结构薄膜中存在明显的氧空位缺陷.值得提出的是ZnO纳米薄膜光致发光谱存在异常的特性,采用波长为325 nm的He-Cd激光激发出可见光范围(500~700 nm)内的发光带,强度最强的是橙——红色的光(~600 nm),且肉眼可直接观察到.随着激发光波长在280~380 nm范围内变化,橙——红色光的强度首先增加后减小,在激发光波长350 nm处,强度达到极大,且极大发射的波长出现红移.进一步,结合上述XPS结果以解释这种强可见光的发射,可以认为主要是由薄膜中与氧空位有关的缺陷造成.

英文摘要：

ZnO thin films with different nanostructures are prepared, in which a mixed process involving two main steps is adopted. First, the seed layers are deposited by RF magnetron sputtering, and then, the nano-structural films are grown by hydrothermal synthesis on the basis of deposited ZnO seed layers. The crystallographic studies of the ZnO thin films are carried out by X-ray diffraction (XRD), which show that only one strong peak of (002) wurtzite-type phase zinc oxide, no diffraction peaks for impurities are found. The surface morphologies are visualized using scanning electron microscopy (SEM) and reveal that the surface morphologies of the ZnO thin films obtained by different hydrothermal treatments are different: one kind is with nanorods perpendicularly grown on the substrates, and the another is with nanosheets petal-likely distributed on the substrate surfaces, although the ZnO seed layers are all with continuous and compact structure. The chemical natures of the ZnO thin films are characterized by X-ray photoelectron spectroscopy (XPS), which indicate that the ratio of O to Zn in lattice of ZnO is close to "1" for sputtered seed layers, while for nano-structural ZnO thin films, the concentrations of latticed oxygen are scarce obviously, illustrating many oxygen-related defects exist.Finally, the room-temperature photoluminescence (PL) measurements of the prepared ZnO thin films are performed. The PL spectra of the nano-structural films display anomalous characteristics including a broad and strong orange-red emission band, which can be seen by naked-eyes. Therefore, the mixed method supplies a simple, inexpensive and effective method to fabricate excellent orange-red luminescence materials. The anomalous broad and strong emission band can be attributed to the oxygen vacancy defects.