Effect of high pressure on photoluminescence properties of Eu 3+: K–Ba–Al–fluorophosphate glasses

Abstract

The effect of hydrostatic pressure and active ion concentration on the luminescence spectra and lifetimes of Eu 3+-doped P 2O 5–K 2O–BaO–Al 2O 3–KF glasses have been studied up to 44.8 GPa at room temperature. The 5 D 0 → 7 F 0–3 transitions exhibit pressure induced red-shift with different magnitudes. The crystal-field (CF) strengths at ambient condition are 338, 332 and 350 cm −1 for 0.05 mol%, 2.0 mol% and 6.0 mol% Eu 2O 3-doped glasses, respectively. These values slowly increase with increasing pressure and finally reach 518, 410 and 381 cm −1 at the highest pressure. The observed increase in the CF strength parameter is found to have an almost cubic dependence on pressure. The luminescence intensity ratio, 5 D 0 → 7 F 2/ 5 D 0 → 7 F 1, of the Eu 3+ ions is found to decrease with increasing pressure. The decay curves follow single exponential nature for all the three concentrations of Eu 2O 3-doped glasses for the entire pressure range studied.