Preparation and upconversion luminescence properties of LaF3∶[KG-*2]Yb3+,Er3+／SiO2 nanocomposites with core／shell structure

LaF3:Yb3 +,Er3 + nanoparticles were successfully synthesized using solvothermal treatment,and LaF3:Yb3 +,Er3 +/SiO2 core/shell nanoparticles were also prepared with reverse microemulsion technique.The...

Preparation and upconversion luminescence properties of LaF3:Yb3 +,Er3 + /SiO2 nanocomposites with core /shell structure

LaF₃:Yb^{3 +},Er^{3 +} nanoparticles were successfully synthesized using solvothermal treatment,and LaF₃:Yb^{3 +},Er^{3 +} /SiO₂ core /shell nanoparticles were also prepared with reverse microemulsion technique.The crystal structure,morphology and photoluminescence properties of as-prepared core /shell nanoparticles were investigated by X-ray diffraction,transmission electron microscopy and fluorescence spectrophotometer.The results showed that LaF₃:Yb^{3 +},Er^{3 +} nanoparticles are of hexagonal structure and SiO₂ shell is amorphous.The size of LaF₃:Yb^{3 +},Er^{3 +} nanoparticles is 13 nm and the LaF₃:Yb^{3 +},Er^{3 +} /SiO₂ nanoparticles present clearly a core /shell structure with 12 nm shell thickness.The solubility of LaF₃:Yb^{3 +},Er^{3 +} nanocrystals in water and the biocompatibility are both improved by the SiO₂ shell.The upconversion luminescence spectra suggested that the SiO₂ shell has small effect on the upconversion luminescence properties of the LaF₃:Yb^{3 +},Er^{3 +} nanocrystals.The core /shell structure LaF₃:Yb^{3 +},Er^{3 +} /SiO₂ nanoparticles are expected to be used in biological applications.