White emission from Dy³⁺ doped Gd₂O₃-B₂O₃ glass for WLEDs encapsulation

Novel bell-shaped glasses were fabricated to study the electro-luminescence properties of the glasses for LED applications. The physical and optical properties of Dysprosium (Dy³⁺) doped Gd₂O₃-B₂O₃ glasses were synthesised using the standard melt quenching procedure with compositions of 27.5Gd₂O₃-(72.5-x)B₂O₃-xDy₂O₃ (where x = 0.05, 0.1, 0.5, 1.0, and 1.5 mol%). The highest emission intensity of Dy³⁺ doped Gd₂O₃-B₂O₃ glasses was found to be at 0.5 mol% (by 275 nm excitaiton of Gd³⁺ ion) and 1.5 mol% (by 350 nm excitation of Dy³⁺ ion) of Dy₂O₃ concentration. A bright yellow emission corresponding to the transition F_9/2→H_13/2 (at 576 nm) was found in the emission spectra. This emission band was a mix of blue, yellow, and red. Furthermore, the CIE chromaticity diagram for glass 0.5 mol% Dy₂O₃ with color coordinates x = 0.368, y = 0.405, and shows white emission. The decay profiles were investigated for 575 emission and values show decreasing trend with increase in Dy₂O₃ content. Encapsulation of fabricated glasses were made to embed on top of the LED to investigate electro-luminescence spectra. From all results, this glasses could be used for LED encapsulation.