Preparation and characterization of tunable YVO4: Bi3+, Sm3+ phosphors

Yttrium vanadate phosphors co-doped with Bi3+- and Sm3+ ions have been prepared via the solid-state reaction as well as via the sol-gel method. The luminescence studies demonstrate the potential of the prepared phosphors as multi-color emitters, which can be achieved by adjusting the excitation wavelengths. The excitation spectra of Bi3+- and Sm3+ co-doped phosphors clearly revealed energy transfer from Bi3+ to Sm3+ ions. When the co-doped phosphors were excited at 254 nm, the emission from Bi3+ was dominant. Upon excitation at 365 nm, the emission from both Bi3+ and Sm3+ was detected. With 410 nm excitation, Sm3+ ions were selectively excited to yield intense red emission. It is shown that the prepared phosphors with optimal concentrations of Bi3+ and Sm3+ can be excited at 254, 365 and 410 nm to yield yellow, orange and red emissions, respectively.