LAUSR

Abstract Here we report the successful preparation of upconversion (UC) gadolinium oxysulfate (Gd2O2SO4) hollow nanoparticles with sensitizer Yb3+ and activator Er3+ co-doped through a biomolecule-assisted hydrothermal route and followed by calcination. By changing the experimnetal parameters, including the reaction temperature and surfactant type and concentration, the particle size and morphology can be regulated. Under the excitation of 980 nm laser, the red-to-green (R:G) emission intensity ratio is about 21:1, indicating the red emission color of 90%Gd2O2SO4:9%Yb3+,1%Er3+ hollow nanoparticles. The influence of the low temperature on luminescence is interpretated with enegy transfer mechanism. The red emission color and long lifetime at red emission regions enable their promising advanced luminescence microscopy applications.