Photoluminescence of Ce3+,Tb3+:Y2O3 nanoclusters embedded in SiO2 sol–gel glasses

Ce3+ doped and Ce3+,Tb3+ codoped Y2O3 nanoclusters embedded in SiO2 glasses were prepared by sol–gel method. Intensive photoluminescence with a strong blue band at 420 nm and a weaker band at 480 nm was observed from 1% Ce3+:10% Y2O3–SiO2 samples, and strong green emission at 543 nm from Tb was obtained in 1% Ce3+,1% Tb3+:10% Y2O3–SiO2 samples. Excitation spectra reveal that the 5d state of Ce3+ covers UV range from 240 to 380 nm; energy transfer from 5d state of Ce3+ to Tb3+ is very efficient, and the absorption of Ce3+ in UV is the dominant energy source for the green emission of Tb3+.