Effect of co-doping metal ions (Li+, Na+ and K+) on the structural and photoluminescent properties of nano-sized Y2O3:Eu3+ synthesized by co-precipitation method

• Nano-sized Y2O3:Eu3+ were synthesized by co-precipitation method.
• Codoping mechanism in Y2O3:Eu3+ with metal ions has been explained in detail.
• M+ ions co-doping improve PL intensity above the quenching conc. for Y2O3:Eu3+.

Nano-sized yttria (Y2O3) doped with Eu3+ powders were successfully synthesized by co-precipitation method, where the quenching concentration for photoluminescence study of Eu3+ ions is 12 mol% which is much higher than the micro-scaled powders. The effect of changing concentration of co-dopants (Li+, Na+ and K+) along with Eu3+ (12 mol%) is studied on optical properties of Y2O3 nanoparticles. The results showed that the incorporation of these metal ions can further improve the luminescence intensity. The highest emission intensity was observed with 6 mol% of Li+, 2 mol% of Na+, and 1 mol% of K+ doping in Y2O3:Eu3+(12 mol%) nanoparticles given by the formula (Y0.82mol%Eu0.12mol%Li0.06mol%)2O3, (Y0.86mol%Eu0.12mol%Na0.02mol%)2O3, and (Y0.87mol%Eu0.12mol% K0.01mol%)2O3 respectively. The structural, morphological and optical properties were studied by X-ray diffraction, Rietveld refinement, transmission electron microscopy, Fourier transform infrared spectroscopy, and Photoluminescence spectroscopy. XRD studies followed by Rietveld refinement confirmed the body-centered cubic structure of doped nanophosphors. All the powders were well crystallized and the emission intensity was observed to increase further from quenching concentration of Eu 12 mol% with co-doped samples.