氧氩流量比对ZnO薄膜的微结构及其发光特性的影响

Influence of O_2/Ar Flow Ratio on Microstructures and Photoluminescence of ZnO Films

在室温下,利用射频磁控反应溅射法分别在硅片和石英玻璃上制备ZnO薄膜。通过控制O2/Ar流量比,研究O2/Ar流量比对ZnO薄膜的微结构、表面形貌及其光致发光特性的影响。X射线衍射仪和原子力显微镜结果显示,当O2/Ar流量比为3∶4时,所得薄膜结晶度最佳,表面粗糙度为0.725 nm;荧光光谱显示,ZnO薄膜在波长407 nm附近出现紫光发光峰,该发光峰源于氧空位浅施主能级到价带顶的电子跃迁,发射强度随O2/Ar流量比的增加先减小后增加。

The ZnO films were deposited by reactive RF magnetron sputtering on Si and quartz substrates.The impacts of growth conditions,including the flow ratio of oxygen and argon,pressure,substrate temperature,and sputtering power,on ZnO film’s quality were studied.Its microstructures and optical properties were characterized with X-ray diffraction,atomic force microscopy,and fluorescence spectroscopy.The results show that the ratio of oxygen and argon flow rate strongly affects the microstructures of the ZnO films.For example,at a ratio of 3∶4,the film is found to be highly crystalline with the lowest surface roughness of 0.725 nm.The strong violet emission,peaking at 407 nm,was observed,possibly because of the electron transition between the shallow oxygen donor levels to the top valence band of ZnO.As the ratio increased,the violet emission peak first rapidly moves up,then,slowly decreases.