Plasmon-enhanced upconversion and quantum-cutting of water-soluble Au@SiO2/NaYF4:Tb3+,Yb3+@NaYF4 nanocomposites

Au@SiO 2 /NaYF 4 :Tb 3+ ,Yb 3+ @NaYF 4 nanocomposites are acquired by combining Au@SiO 2 nanorods with ligand-free NaYF 4 :Tb 3+ ,Yb 3+ @NaYF 4 nano-particles in water solution due to the electrostatic attraction. Plasmon-enhanced upconversion (UC) and quantum-cutting (QC) are both obtained and optimized in these nanocomposites by adjusting SiO 2 shell thickness and concentrations of Au@SiO 2 . While the thickness of SiO 2 shell is 35 nm, the enhancement factor of UC and QC reaches maximum as 1.91 and 3.47 times, respectively. The nanocomposites may be applied in biological fluorescence label, super-resolution imaging and solar cells, etc.