Synthesis and photoluminescence properties of multicolor tunable GdNbO4: Tb3+3+, Eu3+3+ phosphors based on energy transfer
Abstract
A color-tunable phosphor based on Tb3+3+/Eu3+3+ co-doped GdNbO4 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 Tb3+3+/Eu3+3+ single-doped and co-doped phosphors were well indexed to the pure GdNbO4 phase. The GdNbO4 host was proved to be a self-activated phosphor with broad absorption range from 200 nm to 325 nm. When Tb3+3+ ions were added into the host lattice, the energy transferring from host to Tb3+3+ was identified. And the broad absorption in the UV region was changed and enhanced. Therefore, we selected Tb3+3+ as the sensitizer ion, and adjusted red component from Eu3+3+ to control the emission color. The energy transfer from Tb3+3+ to Eu3+3+ 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 GdNbO4, GdNbO4:Tb3+3+, and GdNbO4:Tb3+3+, Eu3+3+ phosphors may have potential application in the UV white-light-emitting diodes (w-LEDs) and display devices.
