Photoluminescence and energy transfer studies in Ce3+-Sm3+co-doped phosphate glasses

0.5Ce3+-xSm3+ (x = 0.11, 0.68 and 1.05 mol%) co-doped phosphate glasses were successfully synthesized via melt-quenching method and analyzed using absorption, photoluminescence and decay curves. According to Judd-Ofelt formalism, the omega 2, omega 4 and omega 6 parameters were determined and used to obtain some radiative properties. With the increasing of Sm3+ concentration, it was noticed the decrease of emission peak intensity and decay curves of Ce3+ due to the energy transfer Ce3+-> Sm3+. Moreover, it was observed that the intensity of Sm3+ emission increases until 0.68 mol%, then decreases for the 1.05 mol% Sm3+ concentration. According to the decay curves of Sm3+, this decreasing can be explained by the cross relaxation between Sm3+ ions. The calculated lifetimes by Judd-Ofelt theory and the experimental lifetimes for the prepared phosphate glasses were obtained. The dependence of the emission intensity on the concentration of doping ions has been explained using energy transfer models in order to obtain the optimum Sm3+ concentration.