以NH4HCO3-NH3·H2O为混合沉淀剂, 采用化学共沉淀法制备CaMoO4：Eu3+红色荧光粉. 通过TG-DTA和XRD研究CaMoO4：Eu3+前驱体的热分解和晶相形成过程; 采用SEM和PL表征了该荧光粉的表面形貌和发光性能, 并与NH4HCO3沉淀剂、NH3·H2O沉淀剂合成的CaMoO4：Eu3+荧光粉以及高温固相法制备的荧光粉进行对比. 结果表明, 煅烧温度700℃时, 前驱体能够完全转换成单一CaMoO4：Eu3+白钨矿结构; 煅烧温度900℃制备的荧光粉发光强度达到最大值; 采用混合沉淀剂制备的荧光粉大小均匀、无团聚、呈类球型, 平均粒径0.9μm. 与高温固相法比较, 其激发光谱中的Eu-O电荷迁移带向长波方向微小移动, 而7F0→5L6(394nm)和7F0→5D2(465nm)的强电子吸收能有效改善红色荧光粉使用性能; 与单独的NH4HCO3或NH3·H2O沉淀剂或高温固相法相比, 该荧光粉发光性能显著改善, 发光强度为传统固相法的2倍.
Using NH4HCO3-NH3·H2O as a mixed precipitator, CaMoO4：Eu3+ red phosphor was successfully synthesized by chemical co-precipitation method. The processes of thermal decomposition and phase formation for CaMoO4：Eu3+ precursor were analyzed by TG-DTA and XRD. Compared with solid-state method, both surface morphology and luminescence properties of CaMoO4：Eu3+ red phosphor using precipitators NH4HCO3, NH3·H2O and NH4HCO3-NH3·H2O are evaluated by means of SEM and PL respectively. After calcination at 700℃, the precursor is completely converted to a single scheelite structure of CaMoO4：Eu3+. Photoluminescence intensity of the phosphor reaches the maximum value at 900℃. The phosphor prepared by using mixed precipitator is uniform spherical particle, and has no aggregation with average size of 0.9μm. Compared with solid-state method, the Eu-O CTS of the red phosphor slightly shifts toward long wavelength. The strong electron absorbability of 7F0→5L6 (394nm) and 7F0→5D2 (465nm) effectively improves the performance of red phosphor. In addition, the photoluminescent intensity from the mixed precipitation is increased to 2 times of that of the red phosphors prepared by solid-state method.
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