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采用水热-烧结法制备了性能良好的Eu3+/Tm3+共掺LaF3和LaOF纳米晶体.在波长为532nm的激光激发下,实现了共掺样品中Tm3+对Eu3+的荧光增强效应.结果发现,当三价稀土离子Tm3+作为敏化剂被共掺到LaF3:Eu3+和LaOF:Eu3+纳米晶体中时,掺杂Eu3+的荧光发射得到了显著的增强,其增强倍数与Tm3+离子的浓度密切相关.与单掺Eu3+离子的LaOF:Eu3+纳米晶体相比较,Tm3+离子的掺入可使氟化物纳米晶体中原本已经很强的5D0→7F2(612nm)红色荧光辐射又增强了一个数量级,从而获得拥有良好颜色纯度和极高辐射强度的红色荧光纳米材料.依据实验观测结果和晶体结构对称性特点,研究了共掺体系中荧光增强的产生机理以及局域对称性变化对于荧光强度的影响.
Eu3 + / Tm3 + co-doped LaF3 and LaOF nanocrystals were prepared by hydrothermal-sintering method.Under the excitation of a wavelength of 532 nm, the fluorescence enhancement effect of Tm3 + on Eu3 + in the co-doped sample was achieved. As a result, When the rare earth ions Tm3 + were codoped into LaF3: Eu3 + and LaOF: Eu3 + nanocrystals as the sensitizer, the fluorescence emission of doped Eu3 + was significantly enhanced, and its enhancement factor was closely related to the concentration of Tm3 + ions. Eu3 + ion LaOF: Eu3 + nanocrystals, the incorporation of Tm3 + ions in the fluoride nanocrystals already strong 5D0 → 7F2 (612nm) red fluorescence was enhanced by an order of magnitude to obtain a good color purity and Very high radiation intensity of red fluorescent nanomaterials.According to the experimental observations and the symmetry of crystal structure, the mechanism of fluorescence enhancement in co-doped system and the influence of local symmetry on the fluorescence intensity were studied.