Electrospinning-derived Tb2(WO4)3:Eu3+nanowires: energy transfer and tunable luminescence properties

Abstract

One-dimensional Tb₂(WO₄)₃ and Tb₂(WO₄)₃:Eu³⁺ nanowires have been prepared by a combination method of sol–gel process and electrospinning. X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL), low voltage cathodoluminescence (CL) and time-resolved emission spectra as well as kinetic decays were used to characterize the resulting samples. The as-obtained precursor samples present fiber-like morphology with uniform size, and Tb₂(WO₄)₃ and Tb₂(WO₄)₃:Eu³⁺ nanowires were formed after annealing. Under ultraviolet excitation and low-voltage electron beams excitation into WO₄²⁻and the f–f transition of Tb³⁺, the Tb₂(WO₄)₃ samples show the characteristic emission of Tb³⁺ corresponding to ⁵D₄–⁷F_{6, 5, 4, 3} transitions due to an efficient energy transfer from WO₄²⁻ to Tb³⁺, while Tb₂(WO₄)₃:Eu³⁺ samples mainly exhibit the characteristic emission of Eu³⁺ corresponding to ⁵D₀–⁷F_0, 1, 2 transitions due to an energy transfer occurs from WO₄²⁻ and Tb³⁺ to Eu³⁺. The increase of Eu³⁺ concentration leads to the increase of the energy transfer efficiency from Tb³⁺ to Eu³⁺. The PL color of Tb₂(WO₄)₃:x mol% Eu³⁺ phosphors can be tuned from green to red easily by changing the doping concentration (x) of Eu³⁺, making the materials have potential applications in fluorescent lamps and color display fields.