通过微乳液-水热法制备了CaMoO4∶Eu3+和CaMoO4∶Eu3+, Bi3+两种红色荧光粉, 并对样品进行表征, 研究其结构、 颗粒形貌及发光性质。 结果表明, 所制样品为白钨矿结构, 属于四方晶系。 SEM显示所制纳米粒子是四方片状结构, 颗粒大小为1.5～2.5 μm。 光致发光(PL)光谱显示, Eu3+摩尔浓度为5%时616 nm发射峰最强, 对应于Eu3+的5D0→7F2电子偶极跃迁; 随CaMoO4∶xEu3+荧光粉中Eu3+掺杂浓度变化, 导致色度坐标(CIE)值由橙黄色(0.514, 0.537) 变化到白色(0.339, 0.333); 在CaMoO4∶5%Eu3+, yBi3+红色荧光粉中, 由于Bi3+对Eu3+的敏化作用, 使其发光强度增强, 当Bi3+浓度为3%时, 发光强度最高; 随着Bi3+掺杂浓度的增加, CaMoO4∶5%Eu3+, yBi3+荧光粉由橙黄色(0.497, 0.347)调节到红色(0.585, 0.349)。

Europium doped CaMoO4 and bismuth co-doped CaMoO4∶Eu3+ phosphors were prepared via microemulsion-hydrothermal method. The structure, morphology and luminescence properties of samples were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM) and fluorescence spectroscopy, respectively. The XRD patterns of as-prepared samples were in agreement with the PDF # 29-0351 of CaMoO4, which indicated that the phosphor possessed tetragonal crystal structure. SEM images showed that the samples were basically flake in shape and their average size was 1.5~2.5 μm. The critical molar concentration of activator (Eu3+) in CaMoO4∶Eu3+ was 5%, and the predominant peak of CaMoO4∶Eu3+ located at 616 nm, corresponding to the 5D0→7F2 electronic dipole transition of Eu3+. The photoluminescence color can be tuned from orange-yellow (0.514, 0.537) to white (0.339, 0.333) by adjusting the doping concentrations of Eu3+ ions. To enhance the red emission intensity of Eu3+, Bi3+ was used to co-dope CaMoO4∶Eu3+ as sensitizers. When the concentration of Bi3+ is 3%, luminescence intensity was maximum. The chromaticity coordinates (CIE) varied from orange (0.497, 0.347) to red (0.585, 0.349) with increasing the content of Bi3+.