水热法促进EuVO_4@YVO_4核壳结构纳米颗粒中Eu~(3+)的扩散及其对发光性能的影响

采用共沉淀法制备了EuVO4@YVO4核壳结构纳米颗粒,然后用聚电解质聚苯乙烯磺酸钠对其进行包覆和保护,并在200?C下对样品水热处理0—48 h.在水热处理48 h后,样品的发光强度增强了约5倍,平均发光寿命由0.410 ms延长至0.579 ms.对样品的发光衰减曲线的拟合、分析为Eu3+的扩散提供了有力的证据.这种自内而外的扩散降低了样品核心中Eu3+的局域浓度,削弱了浓度猝灭效应,同时又能够避免表面猝灭效应的发生,从而使得样品的发光寿命变长、发光效率迅速提升.

Hydrothermal diffusion of Eu3+ in EuVO4@YVO4 core-shell nanoparticles and its influence on luminescent properties

EuVO₄@YVO₄ core-shell nanoparticles (NPs) are synthesized, coated by poly(sodium 4-styrenesulfonate) and hydrothermally treated at 200 ℃ for 0-48 h. The photoluminescence (PL) intensity of as-prepared sample is enhanced by about 5 times after 48-hour hydrothermal treatment, and the average lifetime is raised up from 0.410 ms to 0.579 ms. Further studies of hydrothermal time-dependent PL decay curves provide evidence for the diffusion of Eu³⁺ in core-shell NPs, which could reduce the concentration quenching in particle core and hence enhance the PL efficiency. This thermal diffusion strategy based on ion-doped core-shell NPs could be used to prepare luminescent NPs with high efficiency if designed elaborately.
Keywords： 4@YVO₄')" href="#">EuVO₄@YVO₄ core-shell nanoparticles thermal diffusion concentration quenching