纳米晶CaWO_4∶Dy^(3+)的制备和发光性质的研究

Preparation and luminescent properties of nanocrystalline CaWO_4∶Dy^(3+)

使用共沉淀法制备了纳米晶CaWO4∶Dy3+发光粉体。通过对比不同煅烧温度下样品的发射谱,发现所制备样品均可观测到Dy3+离子的强室温特征发射。用基质吸收峰和353nm分别激发纳米晶CaWO4∶Dy3+,由其发射谱可推测出样品中的基质和Dy3+离子之间存在能量传递。给出了纳米晶CaWO4∶Dy3+的发光机制图并且从微观解释了基质和稀土离子之间的能量传递。通过对比不同掺杂浓度下Dy3+离子发射光谱,发现将Dy3+掺杂到CaWO4基质中会发生浓度猝灭。

The nanocrystalline CaWO4 ∶ Dy3＋ samples were prepared by co-precipitation method.With the comparison of emission spectrums of CaWO4 ∶ Dy3＋ annealed at different temperature,the sharp characteristic emissions were found in all samples.With the comparison of emission spectra of CaWO4 ∶ Dy3＋ excited by the absorption peak of the host and 353 nm,the energy transfer was observed between the nanocrystalline CaWO4 host and the rare earth ions Dy3＋.The photoluminescence schematic diagram of CaWO4 ∶ Dy3＋ was obtained and the energy transfer was explained from micro-structure.The effect of the doped Dy3＋ concentration on the fluorescence emission intensity was discussed,and the results showed the concentration quenching depended on the doped Dy3＋ concentration.The optimum concentration for the luminescence of Dy3＋ is determined to be 1 mol%.