上海科技大学知识管理系统

In this contribution, we provided a new, simple, cheap, repeatable and easily tunable method to synthesize CaF2: Nd3+ NPs using coprecipitation strategy. By controlling reaction time, temperature and solute/solvent, CaF2: Nd3+ NPs with dimeters ranging from 2.2-4.6 nm were synthesized. Then we optimized the Nd3+ concentration and found CaF2:6Nd(mol%) NPs with strongest luminescence. Furthermore, to further enhance the fluorescence of the optimized NPs, we explored both Li+ doping and Ce3+ doping to afford highly fluorescent CaF2: Nd3+ NPs. For Li+ doping CaF2:6Nd,xLi(mol%) NPs, under the excitation of 800 nm, a similar to 4-fold fluorescence enhancement was observed, while for Ce3+ doping CaF2:6Nd,xCe(mol%) NPs, a 10.4-fold fluorescence enhancement was observed. Li+ doping leads to two fluorescence maxima at 4% and 30%, mainly dominated by charge compensation, and increased crystallity/grain size, separately. As comparison, Ce3+ doping resulted in the monotonical increase of the fluorescence, dominated by lowered crystal symmetry, changed local crystal field and dissociated Nd3+- Nd3+ clusters.