微波水热法氧化锌的低温合成及发光特性研究

Low Temperature Growth and Luminescent Properties of Zinc Oxide Synthesized by Microwave Assisted Hydrothermal Method

采用微波水热合成的方法,在95~150℃的生长温度下得到了氧化锌(ZnO)样品,扫描电镜(SEM)的结果表明,当生长温度从95℃变为150℃时,样品的结构从六方柱状结构颗粒变为小颗粒团聚成的球状结构.由X射线衍射结果可知,低温生长的样品为氧化锌,当生长温度升高后有其他杂质峰出现.由光致发光结果可知,随着生长温度的升高,可见光发光的相对强度增强,这表明样品中的缺陷增多.95℃下生长样品的变功率的荧光光谱表明,随着入射光功率的增大,样品的带边发光峰从3.233 eV变化到3.014 eV,出现了明显的红移;可见光发光与带边发光强度的比值先增大后减小,表明可见光的发光与带边发光有明显的竞争关系.

Zn O samples are synthesized by microwave hydrothermal method at the growth temperature of 95-150℃.The results of scanning electron microscopy(SEM) show that when the growth temperature is changed from 95℃ to 150 ℃,the structure of the samples changes from hexagonal columnar particles to spherical structures composed of small particles.According to the X-ray diffraction results,the samples growing at low temperature are zinc oxide,and other impurity peaks emerge when the growth temperature is increased.From the photoluminescence results,it can be seen that with the increase of growth temperature,the relative luminescence intensity of visible light increases,which indicates that the defects in the samples increase.The fluorescence spectrum of the variable power of the samples at 95 ℃ show that with the increase of the incident light power,the band edge luminescence peak of the samples changes from 3.233 eV to 3.014 eV,with an obvious red shift.The ratio of visible luminescence to band luminescence intensity increases first and then decreases,indicating that there is an obvious competitive relationship between visible luminescence and band luminescence.