Optical and white light emission properties of Dy3+ ions doped zinc oxyfluorotellurite glasses

The dysprosium ions-doped zinc oxyflluorotellurite glasses of three different compositions have been synthesized and analyzed their vibrational, thermal, optical and white light emission properties. The differential thermal analysis curves, Fourier Transform Infrared, absorption, emission and excitation spectra and lifetimes from the luminescent level (⁴F_9/2) have been measured and analyzed. Absorption spectra have been characterized in the frame of Judd-Ofelt model to determine essential radiative properties namely, transition probabilities, calculated lifetimes and branching ratios of the ⁴F_9/2 luminescent level. Photoluminescence spectra of the glasses are measured by exciting with 388 nm broad band and 355 nm laser. The glasses emit intense white luminescence with 388 nm broad band excitation. The CIE chromaticity color coordinates of one of the glass are nearer to the equal energy point. Decay time profiles of the ⁴F_9/2 state are non-exponential for three glasses under study where their effective lifetimes have been evaluated. Quantum efficiencies of the glasses vary from 30 to 62% with change in ZnF₂ content.