Investigation of luminescence properties of Ho³⁺ doped barium, zinc and gadolinium based phosphate glasses

Abstract

10BaO-10ZnO-10Gd2O3-69P2O3-1Ho2O3 (ZBOH) and 10BaO-10ZnO-10GdF3-69P2O3-1Ho2O3 (ZBFH) were developed by the melt-quenched-method. The synthesized ZBOH and ZBFH glass samples were characterized for Uv-Vis-NIR, excitation, emission, decay time profile measurements and physical properties. It is observed that the ZBOH glass have higher density and refractive index as compared to the ZBFH glass. From the band gap calculation, it is observed that the oxyfluoride glasses have lower band gap as compared to the oxide glasses which indicate more \non bridging oxygen in oxyfluoride glasses. The emission spectra recorded at λex = 449 nm show four emission bands at 5F2 (477 nm), 5F3 (495 nm),5F4 +5S2(545 nm) and5F5 (659 nm) from 5I8-levels. Judd-Ofelt (J-O) theory is used to investigate the J-O intensity parameters, transition probability, stimulated emission cross section and branching ratio. From the results it's perceived that the radiative transition probability and branching ratio values are higher for 5F4 →5I8 transition as compared to the other transitions.