利用高温热溶剂法合成了不同Yb3+和Tm3+掺杂浓度的NaYF4∶Yb3+,Tm3+上转换发光纳米粒子。利用扫描电子显微镜、X射线衍射分析、荧光光谱对样品进行形貌和发光性质的表征。结果表明, 不同Yb3+和Tm3+离子掺杂浓度对纳米粒子的上转换发光性质有很大影响。随着Tm3+离子浓度的提高, Tm3+离子之间的浓度猝灭和交叉弛豫效应对发光强度的影响愈来愈显著, 导致纳米粒子的发光猝灭; 同样, 随着Yb3+浓度的提高, 纳米粒子的发光强度也是先增大后减小, 这是因为Yb3+离子浓度掺杂过高导致发光猝灭。

The NaYF4∶Yb3+,Tm3+ nanocrystals were synthetized with different doping concentrations of Yb3+, Tm3+ ions by a thermal decomposition method. The morphology, crystalline phase and optical properties were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and luminescent spectra．With the concentrations of Tm3+ increasing, the emission intensity of Tm3+ firstly increased and then decreased because of the effects of ion concentration quenching and cross relaxation between the neighboring Tm3+. The decrease of the luminescent intensity with the increase of Yb3+ ions is due to the concentration quenching effect.