Understanding the structural and optical evolution of Eu3+ and Dy3+ co-doped YVO4 phosphors across concentration series for lighting applications
Houssem Eddine Sekrafi, Eya Hergli, Stanislav Ferdov, Paulo J. G. Coutinho, L. Rebouta
Abstract
YVO 4 nanoparticles co-doped with Eu 3+ and Dy 3+ ions were successfully synthesized using a conventional co-precipitation method. The resulting phosphors exhibited a single-phase trigonal YVO 4 structure, with nanoparticles averaging approximately 60 nm in size, obtained by measurements carried out with scanning electron microscope images. UV-visible diffuse reflectance spectroscopy analysis reveals that the direct band gaps of our samples fall within the range of 3.6–3.75 eV. After a thorough analysis, the optimal doping concentration was identified as 2 at.% Eu³⁺ and 2 at.% Dy 3+ ions co-doping, exhibiting the strongest up-conversion emission intensity under 310 nm excitation. YVO 4 :x(Eu 3+ , Dy 3+ ) phosphors exhibit distinct bands corresponding to transitions of Dy 3+ and Eu 3+ ions from their 4 F 9/2 and 5 D 0 excited states, respectively. The energy transfer from Dy 3+ to Eu 3+ is validated through electric dipole–dipole interaction, with a critical distance of 15.63 Å. YVO 4 nanoparticles co-doped with Eu 3+ and Dy 3+ ions exhibit wide-range control over their photoluminescence color by regulating the concentration of both dopants. These findings suggest great potential for applications in current industrial settings.