Structure and upconversion luminescence properties of BaYF5:Yb3+, Er3+ nanoparticles prepared by different methods

▶ Two different fluoride source were used to synthesize BaYF5:Yb3+, Er3+ by the hydrothermal method, and the sizes of the as-prepared spherical particles were about 30 nm (NH4BF4 as fluoride source) and 100 nm (NH4HF2 as fluoride source). ▶ BaYF5:Yb3+, Er3+ nanoparticles prepared by the co-precipitation method are irregular, and many clusters and agglomerates can be seen. ▶ The UC fluorescence has been realized in all the as-prepared BaYF5:Yb3+, Er3 samples upon 980 nm excitation.