Judd-Ofelt and energy-transfer analysis of Er3+ doped in CaSc2O4 ceramic samples

A Judd-Ofelt analysis of Er3+ in CaSc2O4 ceramic samples is performed. The Judd-Ofelt parameters are found (Ω2=3.88×10−20 cm2, Ω4=1.83×10−20 cm2, Ω6=0.83×10−20 cm2) and the radiative lifetimes of Er3+ energy levels and the branching ratios of Er3+ transitions are calculated. The luminescence lifetimes of metastable energy levels are obtained experimentally and the quantum efficiencies of these levels are calculated. The luminescence kinetics of the thermalized levels (2H11/2, 4S3/2) at various Er3+ concentrations is used to characterize the cross-relaxation processes that influence these green-emitting levels. The decays of these levels are well described by the Inokuti-Hirayama model for dipole-dipole interaction. The CDA microparameter was found to be 6.7×10−39 cm6 s−1.