Optical-Luminescent and Dielectric Spectroscopy of B₂O₃–ZnO–SrO–CaO Glasses Doped with Dy³⁺ Ions for White Light Emission Applications

Optical-luminescent and dielectric properties of (B2O3)60–(ZnO)20–(SrO)10–(CaO)10 borate glasses doped with Dy3+ ions have been investigated. The influence of doping the borate glass samples with Dy3+ ions on the dependences of dielectric constant and dielectric loss were analyzed in the 4 Hz – 200 kHz frequency range. The electrical polarization mechanisms contributing to electrical permittivity and models describing AC conductivity were discussed. Absorption analysis identified typical absorption transitions characteristic of Dy3+ ions in the prepared glass samples. The photoluminescence excitation spectra were obtained by monitoring emissions at 486 and 580 nm within the 230–440 nm range, with the most intense peak at 350 nm corresponding to 6H15/2 → 6P7/2 transitions in Dy3+ ions. The borate glass samples doped with Dy2O3 showed excellent luminescence when excited at 350 nm. Modifying the concentration of Dy3+ ions makes it possible to change the ratio of yellow to blue emissions, allowing for control over the emitted light spectrum, including the production of white light. The sensitivity of yellow emission to changes in the surrounding environment of Dy3+ ions additionally provides an avenue for tuning luminescent properties. The CIE coordinates demonstrate that the emission of Dy3+-doped glasses is near the white light region, which opens up opportunities for potential applications of this material in white LEDs and other optoelectronic devices.