Sol-gel synthesis and enhanced 1.54 μm emission in Y2O3:Yb3+, Er3+ nanophosphors co-doped with Ce3+ ions

Nano-sized Y2O3:Yb3+, Er3+ phosphors were synthesized by sol-gel method and characterized by X-ray diffraction, scanning electron microscope, near-infrared and upconversion fluorescence spectroscopy. The phosphors calcined at 1100 °C for 2 h were confirmed to be cubic Y2O3 phase with well-crystallized particles. With the introduction of Ce3+ ions at proper doping concentration, the 1.534 μm emission of Er3+ was found to be greatly enhanced, while the green and red upconversion emission intensity obviously decreased. The enhancement of 1.534 μm emission could be attributed to the phonon-assisted energy transfer process between Ce3+ and Er3+ ions.