Effect of ZrO2 on the colour tuning ability of Cu2 + , Dy3+ and Cu2+/Dy3+-integrated sodium barium aluminium borate glasses

The present investigation reports on ZrO 2 -modified Na 2 O-BaO-Al 2 O 3 -B 2 O 3 (NBABZ) glasses doped and co-doped with (Cu 2+ , Dy 3+ ) ions. The prepared glasses were systematically studied using various analytical techniques, including XRD, FESEM, FTIR, UV–visible-NIR, and PL spectroscopy. The XRD analysis confirms the amorphous nature of the prepared samples. Various physical parameters were assessed, revealing that the Cu 2+ /Dy 3+ co-doped NBABZ glass has the highest refractive index (1.6160) and density of 2.835 g/cm 3 , which can be attributed to the balanced network compactness and improved electronic polarizability. Optical absorption studies show a gradual decrease in the E g indirect with the incorporation of ZrO 2 and dopant ions, reaching a minimum value of 1.67 eV for the Cu 2+ /Dy 3+ co-doped NBABZ glass. PL results reveal characteristics of Dy 3+ emissions, with enhanced intensity observed in the Cu 2+ /Dy 3+ co-doped NBABZ glass, indicating possible sensitization effects associated with the Cu 2+ -ions. Consequently, the Cu 2+ /Dy 3+ co-doped NBABZ glass exhibits the highest Y/B emission ratio of 1.43 compared to the single Dy 3+ -doped NBABZ glass. The CIE chromaticity coordinates of (0.3454, 0.3640) lie close to the white-light region. These results suggest that Cu 2+ /Dy 3+ co-doped NBABZ glasses are promising candidates for solid-state lighting and photonic applications. • Cu 2+ /Dy 3+ co-doped glass shows near-white emission, suitable for solid-state lighting. • NBABZCuDy glass exhibits the highest refractive index (1.6160) and lowest bandgap. • Strong Cu 2+ → Dy 3+ energy transfer markedly enhances luminescence in co-doped glass. • Co-doping gives the highest Y/B ratio (1.43), revealing strong Dy 3+ site asymmetry.