衬底温度对ZnMgO薄膜结构和光致发光性能的影响

利用超声喷雾热解方法以不同的沉积温度(450～550 ℃)在石英衬底上制备出一系列ZnMgO薄膜。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和光致发光谱(PL)表征了样品的晶体结构、表面形貌和光学性能。结果表明衬底温度对薄膜结构性能和光学特性影响显著。所有薄膜都呈六角纤锌矿多晶结构，其中在530 ℃条件下制备的样品C轴择优最明显，晶粒尺寸均匀，表面形貌平整，结晶质量最好。薄膜的光致发光谱显示随着温度的升高深能级跃迁范围逐渐减小，近紫外带边发光峰逐步出现。衬底温度为530 ℃时在374.5 nm处出现了明显的近紫外发光峰，且几乎没有明显的深能级跃迁出现。

Effect of Substrate Temperature on Structure and Photoluminescence of ZnMgO Films

ZnMgO films were deposited on quartz glass substrates by the ultrasonic spray pyrolysis at different substrate temperatures(450～550 ℃). The structural, surface morphological and optical properties of the samples were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL) spectroscopy. The results demonstrate that the substrate temperature has important effect on structural and optical characteristics. All the films have hexagonal wurtzite polycrystalline structures and the c-axis preferential orientation has an optimum temperature of 530 ℃. The sample prepared at this temperature owns uniform grain size, smooth surface morphology and better crystalline quality. The width of deep-level emission decreases and the near band edge (NBE) ultraviolet emission peak appears with the increase in temperature by the PL spectrum. When the temperature arrives to 530℃, a distinct NBE emission peak can be observed at 374.5 nm, while the deep-level emission is almost undetectable.