Temperature-dependent luminescence properties of Dy3+, Tm3+ single-/co-doped YNbO4 phosphors

Abstract

Dy3+, Tm3+ single-/co-doped YNbO4 phosphors were prepared by a high temperature solid-state reaction method. Rietveld refinement analysis was performed to reveal the phase formation and the doping-induced change of the lattice parameters. The results revealed that monoclinic YNbO4 phosphors were obtained. From temperature-dependent emission spectra, it was found that the total intensities of the emissions of Dy3+ and Tm3+ decreased with increasing temperature, and a new peak originated from 4I15/2→6H15/2 transition of Dy3+ appeared at higher temperatures, and its intensity increased with temperature elevation. The temperature sensing properties of both Dy3+ single-doped and Dy3+, Tm3+ co-doped phosphors were studied. A new model was proposed to describe the temperature dependence of the fluorescence intensity ratio (FIR) of the 456 nm emission to the 487 nm emission in Dy3+, Tm3+ co-doped sample. It was discovered that the sensitivity of Dy3+ single-doped YNbO4 sample was similar with that of Dy3+, Tm3+ co-doped one. Moreover, the chromatic stability versus sample temperature was evaluated according to their color coordinates.