Optics, structures and luminescent properties in Dy3+-doped tellurite glass regulated by Nb2O5

In this work,60TeO2-(35-x)ZnO-xNb2O5–5SrF2-0.5Dy2O3 glasses was prepared to use a high-temperature melting method, where x represents the Nb2O5 content (x = 0,5,7.5,10).Raman spectra studies revealed that increasing the concentration ratio of Nb2O5 to TeO2 resulted in the gradual transformation of [TeO3] and [TeO3+1] units in the glass network to [TeO4] units. This transformation also enhanced the stability of the network structure. The emission peaks of the samples were observed at 481 nm (blue), 576 nm (yellow), and 663 nm (red), which is crucial for white light materials. The luminescent intensity increased with the increase of Nb2O5 concentration, reaching its maximum at 7.5% mol. The CIE 1931 chromaticity coordinates fell within the range of white light, with corresponding color temperatures ranging from 5063 K to 5877 K. All the results show that the fluorescent materials used in high-brightness illumination can be obtained by adding an appropriate amount of Nb2O5 to Dy3+-doped tellurate glass.