菱形二氧化铈的水热合成及发光机理研究

Research on hydrothermal synthesis and photoluminescence mechanism of rhombus CeO2

采用水热法合成了菱形二氧化铈(CeO2)发光材料。采用X射线衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)、紫外可见分光光度计(UV-Vis)、选区电子衍射(SAED)和荧光分光光度计(PL)研究了制备样品的晶体结构、形貌、电荷态、结晶度、光学和发光性质。XRD及XPS分析发现,二氧化铈发光材料存在大量吸附氧,氧空位浓度为1.723 7×1020cm-3。光学性质分析表明,二氧化铈发光材料在400 nm以下具有强的光吸收能力,其光学带隙(Eg)值为3.19 eV。荧光光谱分析显示,在202 nm波长的光激发下,能获得460、470、540、580 nm荧光发射峰,其色度坐标值为(0.188,0.243)。基于实验结果和理论分析,提出了相应的发光机理。

Luminescent materials of rhombus CeO2 was prepared by hydrothermal synthesis method.The crystal structure,morphology,charge state,crystallinity,optical and photoluminescence properties of rhombus CeO2 were characterized by Xray diffraction(XRD),scanning electron microscopy(SEM),UV-visible spectrophotometer(UV-Vis),selected area electron diffraction(SAED) and photofluorescence spectrophotometer(PL).XRD and XPS analysis indicated that there is a large amount of adsorbed oxygen in CeO2 luminescent material,and the oxygen vacancy concentration of this material was 1.723 7×1020 cm-3.Optical properties analysis showed that CeO2 luminescent materials have strong light absorption capacity below 400 nm,and its optical band gap(Eg) value was 3.19 eV.Photoluminescence spectrum analysis showed that four fluorescence emission peaks at 460,470,540,580 nm can be observed under the excitation wavelength of 202 nm,and their chrominance coordinate was(0.188,0.243).Based on the experimental results and theoretical analysis,the corresponding photoluminescence mechanism was proposed.