Luminescent properties of binary MO-2SiO2 (MÂ = Ca2+, Sr2+, Ba2+) glasses doped with Ce3+, Tb3+ and Dy3+

Binary alkali-earth silicate glasses doped with Ce3+, Tb3+, and Dy3+ were obtained by melt-quenching technique and their photo- and radio-luminescence properties were investigated. The disordered structure of the glass is responsible for an inhomogeneous broadening of the electronic radiative 5d1 energy level of Ce3+ due to their localization in several positions with different surroundings, possessing a slightly different local ligand field. The influence of glass matrix composition on the Stokes shift as a function of ionic radius of the cation was shown. The radio-luminescence spectral shapes were related to the simultaneous occurrence of emissions from all Ce3+ configurations with relative weights proportional to their abundance in the glasses. The possibility of excitation of Ce3+ in different localizations was demonstrated and confirmed by the systematic shift of emission from excitation. On the contrary, no shift was observed in the Tb3+ and Dy3+ doped glasses, thanks to the lower effect of ligand field on their radiative electronic levels.