SrWO4:Tb3+ nanoparticles: synthesis, characterization, and luminescence

Nanoparticles of SrWO4 doped with Tb3+ were synthesized in ethylene glycol, Dimethyl sulfoxide, and water. X-ray powder diffractions show that the nanoparticles synthesized in all these solvents have a pure tetragonal scheelite structure without the presence of deleterious phases. Scanning electron microscopy images show that nanoparticles are in the range of 15–25 nm with an inhomogeneous nature. The emission spectra of SrWO4:xTb3+ nanoparticles show the characteristic green emission (545 nm) of Tb3+ ions corresponding to 5D4 → 7F5 transition due to efficient charge transfer from WO42− to Tb3+ ions, when they are excited at 254 nm. Other emissions can be observed due to 5D4 → 7F6, 4, 3 transitions. The optimum concentration of Tb3+ ions for the highest luminescence was found to be 10 mol%. The luminescence intensity of the samples prepared in ethylene glycol is higher than that in Dimethyl sulfoxide and water. The excellent luminescence properties of SrWO4:Tb3+ phosphor makes it as a potential green phosphor.