采用水热法合成了Yb3+-Tm3+共掺BiOBr纳米晶,研究了其上转换发光性能.在980 nm光激发下,样品中Tm3+离子实现了3H4→3H6、1G4→3F4和1G4→3H6跃迁,进而发出强烈的近红外光(801 nm)和较弱的红光(655 nm)与蓝光(485 nm).探讨了样品的上转换发光机理,上转换发光强度与激发功率的关系表明在980 nm激发下Tm3+的蓝光和红光发射为三光子过程,而近红外发光为双光子过程.随着Yb3+浓度增加,近红外发光显著增强,近红外光与蓝光(I801 nm/I485 nm)的发光强度比高达71.4.研究结果表明,Yb3+-Tm3+共掺BiOBr纳米晶在生物荧光标记领域具有潜在的应用前景.%Yb3+-Tm3+ co-doped BiOBr nanocrystals were successfully prepared by hydrothermal method, and its up-conversion luminescence properties was investigated. Under excitation at 980 nm light, an intense near-infrared (801 nm) accompanied by weak red (655 nm) and blue emissions (485 nm) were observed, which were attributed to the3H4→3H6,1G4→3F4 and1G4→3H6transitions of Tm3+ions, respectively. Power dependence studies revealed that blue and red emission resulted from a three-photon process, while the near-infrared emission resulted from a two-photon process, and a possible upconversion mechanism is discussed. As the Yb3+ ions concentration increasing, the overall emission intensity increases and near infrared emission is much stronger than red and blue ones. Consequently, the ratios of near-infrared to visible (I801 nm/I485 nm) reaches 71.4. These results indicate that the Yb3+-Tm3+ co-doped BiOBr nano-crystals have potential applications in biological field as luminescence labeling probers.
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