Optical and luminescence properties of Er3+ doped Sb2O3-Li2O-MO (M=Mg, Ca and Sr) glasses

Sb2O3-Li2O-Er2O3 glasses mixed with various modifier oxides viz., MgO, CaO and SrO have been prepared by the melt quenching technique in this present work. Optical absorption, photoluminescence and decay characteristics were measured at room temperature. The Judd-Ofelt (JO) parameters Omega(2), Omega(4) and Omega(6) for Er2O3 mixed glasses were calculated using absorbance spectra. The emission spectra excited lambda(exc) = 380 nm exhibited emission transitions F-4(7/2), H-2(11/2), S-4(3/2), F-4(9/2) -> I-4(15/2) (Vis region) and I-4(13/2) -> I-4(15/2) (NIR region) of Er3+ doped glasses. Numerous characteristics of radiative parameters viz., A(R), beta(R), tau(R), and sigma(E)(P) for Er2O3 enriched glasses were analyzed and reported, based on JO parameters and the emission spectra. Overall, the results indicated that Er3+ mixed glasses exhibited a substantial increase in the green emission (H-2(11/2,) S-4(3/2) -> I-4(15/2)) intensity of all glass samples. When compared with the other two glasses, the SrO mixed glass having the highest quantum efficiency (eta = 88.2%) of green emission. The structural modifications of Er3+ ions due to modifier oxides were identified by IR spectral studies.