Concentration-dependent spectroscopic properties of Pr3 + ions in TeO2–WO3–PbO–La2O3 glass

• TeO2–WO3–PbO–La2O3 glass as a new host for Pr3 + ions
• Luminescence intensity reaches a maximum at Pr3 + ion concentration of 1020 cm− 3
• Lifetime of 1D2 level dramatically decreases with increasing Pr3 + ion concentration.

The purpose of this work was to investigate the spectroscopic properties of Pr3 + ions of various concentrations embedded in a new matrix, namely a tellurite–tungstate glass with the molar composition 60%TeO2–27%WO3–10%PbO–3%La2O3 (TWPLa). The optical absorption edge of the TWPLa matrix has been described within the Urbach approach, while the absorption and fluorescence spectra of the Pr3 +-doped TWPLa glasses have been analyzed in terms of the standard Judd–Ofelt (J–O) theory along with the luminescence decay of the 3P0 and 1D2 levels of the Pr3 + ion. A significant influence of the Pr3 + ion concentration on the photoluminescence intensity as well as on decrease of the lifetimes of both levels has been explained by a non-radiative energy transfer between the ions through different cross-relaxation channels. The spectroscopic studies have been completed with ellipsometric measurements providing the dispersion relation of the refractive index of the investigated glasses that has been taken into account in the J–O analysis.