网络状表面结构纳米氧化锌的发光特性

Photoluminescent Properties in Zinc Oxide Samples with Network Surface Microstructure

为研究表面形貌对微纳结构氧化锌晶体光学特性的影响,利用气相传输法制备了一种具有特殊表面结构的纳米氧化锌颗粒状样品.应用X射线衍射谱、电子能量散射谱和扫描电镜等对样品结构和形貌进行了分析,结果表明样品具有三种层次结构组成的网络状表面形貌;室温下以波长355nm激光激发样品,观察到紫外峰明显被抑制的发光谱.基于样品表面周期性微结构,用时域有限差分法和严格耦合波分析法对样品发光谱特性及成因进行仿真研究.结果表明,发光谱中紫外峰的被削弱与材料能级结构无关,其形成机理缘于样品表面类蝴蝶翅膀表面微结构,类似于光子晶体表面结构颜色.

In order to investigate influences of microstrucral Znic Oxide samples′ superficial nanotructure on their photoluminescence characteristics,ZnO sample with 2-Dimension network surface nanostructure was fabricated based on vapor phase transport method using zinc powder as a source.Their superficial structure was examined by X-ray diffraction pattern.Scanning electron microscopy picture and photoluminescence spectra excited with 355 nm laser pulse at room temperature were measured.The measuring results show that the structures are composed of three ordered multi-aperture gratings and the special photoluminescent properties,similar to structural colours,resulted from tne network surface,which works as photonic crystals here.The mechanism of this photoluminescent performance was discussed based on finite difference time-domain,rigious coupled-wave analysis methods and the reasonable explaination was present.Finally,the theoretically analysis conclusion was verified by experiment results.