Role of excitation wavelength and dopant concentration on white light tunability of dysprosium doped titania-fluorophosphate glasses

Abstract Dysprosium-doped fluorophosphate glasses (P2O5–CaF2–BaF2–TiO2-Dy2O3) have been prepared using melt-quenching technique and characterized their optical, structural, thermal and photoluminescence properties. Thermal stability (128 °C) of 0.5 mol% Dy2O3-doped glass has been estimated using Differential thermal analysis. Functional groups for 0.5 mol% Dy2O3-doped glass have been studied by Fourier Transform Infrared spectrum. Absorption spectra have been utilized for estimating the Judd-Ofelt (JO) parameters and allied properties. Several excitation wavelengths (350, 365, 387, 425, 452 and 472 nm) have been used for pumping the Dy3+ ions and analyzed for white luminescence. Intense emission has been observed for 0.5 and 1.5mol% of Dy2O3-doped glasses under 387 nm excitation. The 4F9/2 → 6H13/2 transition at 573 nm has unveiled a high stimulated emission cross-section (σSE) of 41.52 × 10−22 cm2 for 0.5 mol% Dy2O3-doped glass. CIE coordinates fall close to the white region in CIE diagram, and hence these glasses are suitable for cold white light emitting diode applications.