Synthesis and photoluminescence properties of multicolor tunable GdNbO₄: Tb3+, Eu3+ phosphors based on energy transfer

Abstract

A color-tunable phosphor based on Tb[Formula: see text]/Eu[Formula: see text] co-doped GdNbO 4 were synthesized by a traditional solid-state reaction method. X-ray powder diffraction (XRD), diffuse reflectance spectra, photoluminescence spectra and decay curves were utilized to characterize the as-prepared phosphors. XRD result indicated that various concentrations Tb[Formula: see text]/Eu[Formula: see text] single-doped and co-doped phosphors were well indexed to the pure GdNbO 4 phase. The GdNbO 4 host was proved to be a self-activated phosphor with broad absorption range from 200 nm to 325 nm. When Tb[Formula: see text] ions were added into the host lattice, the energy transferring from host to Tb[Formula: see text] was identified. And the broad absorption in the UV region was changed and enhanced. Therefore, we selected Tb[Formula: see text] as the sensitizer ion, and adjusted red component from Eu[Formula: see text] to control the emission color. The energy transfer from Tb[Formula: see text] to Eu[Formula: see text] was confirmed based on the luminescence spectra and decay curves. Furthermore, the energy transmission mechanism was deduced to be the dipole–quadrupole interaction. On the whole, the obtained GdNbO 4 , GdNbO 4 :Tb[Formula: see text], and GdNbO 4 :Tb[Formula: see text], Eu[Formula: see text] phosphors may have potential application in the UV white-light-emitting diodes (w-LEDs) and display devices.