Improved luminescent behavior of YVO 4:Eu 3+ ceramic phosphors by Li contents

Abstract

Crystalline phase and surface morphology of phosphors are important factors to determine luminescent characteristics. Li-doped YVO 4:Eu 3+ ceramic samples were prepared by a solid state reaction method. The Li + concentration was varied from 1 to 3 wt% to improve crystallinity and surface morphology of ceramics. Influence of Li doping on luminescent properties of YVO 4:Eu 3+ ceramics has been investigated. Photoluminescence spectra have been measured at room temperature using a luminescence spectrometer and excitation by a broadband incoherent ultraviolet light source with an excitation wavelength of 325 nm. The emitted radiation was dominated by a red emission peak at 620 nm radiated from the 5D 0 → 7F 2 transition of Eu 3+ ions. As Li + ion content increases from 0 to 2 wt%, the photoluminescence (PL) brightness improved. The brightness of 2 wt% Li-doped YVO 4:Eu 3+ ceramic was increased by a factor of 1.43 in comparison with that of YVO 4:Eu 3+ ceramic. The enhanced luminescence resulted not only from the improved crystallinity but also from the enhanced surface roughness. The luminescent intensity and surface roughness exhibited similar behavior as a function of Li + ion concentration.