Structural and spectroscopic properties of Eu3+-doped zinc fluorophosphate glasses

Zinc fluorophosphate (ZFPEu: P2O5–K2O–Al2O3–ZnF2–LiF–Eu2O3) glasses doped with different Eu3+ ion concentrations have been prepared and characterized through DTA, Raman, absorption, luminescence, excitation, phonon side band spectra and decay measurements at room temperature. An intense red luminescence has been observed due to 5D0 → 7F2 transition of Eu3+ ions in these glasses. Raman and phonon side band spectroscopic techniques have been used to investigate the local structure around Eu3+ ions and phonon energy of the host, respectively. The analysis of optical intensities based on absorption and luminescence spectra has been performed under different constraints using Judd–Ofelt (JO) theory. The JO intensity parameters have been used to predict the radiative properties such as radiative lifetime, branching ratio, and stimulated emission cross-section for the 5D0 → 7FJ (J = 0–6) transitions. Decay rates for the 5D0 level of Eu3+ ions has been found to be single exponential for all concentrations. Luminescence properties of the 5D0 → 7F2 transition of Eu3+ ion revealed that the present ZFPEu glasses may be useful for developing visible red lasers as well as optical display devices at around 611 nm.