Photoluminescence and X-ray absorption near edge structure of Eu ions doped SiO2 thin films

Eu doped SiO2 thin films, SiO2(Eu), were prepared by implanting Eu ions into thermal growth SiO2 thin films and co-sputtering of SiO2 and Eu2O3. The red light emission (604 nm) at room temperature from as prepared and annealed SiO2(Eu) films was observed, which is corresponding to the 5D0–7FJ transitions of Eu3+. The blue light emission (443 nm) corresponding to f–d transition of Eu2+ appeared after annealing at high temperature in N2 accompanied by a decrease in intensity of red light. It indicates the conversion of Eu3+ to Eu2+. The Eu-L3-edge X-ray absorption near edge structure (XANES) spectra show the doublet peak structure with energy difference of 7 eV, which confirms the conversion of Eu3+ to Eu2+ at high annealing temperature (Ta) in N2.