Development of Eu3+ doped Li2O-BaO-GdF3-SiO2 oxyfluoride glass for efficient energy transfer from Gd3+ to Eu3+ in red emission solid state device application

Abstract

The Eu3+- doped Li2O-BaO-GdF3-SiO2 glasses were fabricated by conventional melt quenching technique to study its spectroscopic and luminescence properties for lasing potential. The density and molar volume of the glass had been increased with Eu2O3 concentration. An FTIR spectrum is used to study the structural properties of the developed glasses. Two intense peaks were observed in UV–Vis–NIR spectra at 2206 nm (7F6) and 2085 nm (7F1) in NIR region. Under 394 nm excitation LBGFS display five regular emission peaks at (578 nm) 7F0, (590 nm) 7F1, (613 nm) 7F2, (651 nm) 7F3 and (701 nm) 7F4 from 5D0 state, the most intense red emission was found at 613 nm. The characteristic intense red emission peak at 613 nm corresponding to the 5D0 →7F2 transition of Eu3+ ions has been observed for oxy-fluoride glass samples. Efficient energy transfer phenomena from Gd3+ → Eu3+ were observed under 275 nm excitation in these glasses. FTIR measurements reveal that these glasses show non-bridging oxygen stretching of Si-O- at ~929 cm−1. Phonon sideband spectrum confirms the phonon energy ~920 cm−1 for these glasses arising from Si-O-. Increasing trend of IR/O with increasing concentration of Eu2O3 indicates the asymmetric environment around Eu3+ in LBGFS. Higher value of stimulated cross section (σ(λp)) branching ratio (βR) for transition to 7F0 from 5D0 were observed for LBGFS glasses. Decay time decrease with increasing concentration of Eu2O3.