Modifier effect on the spectroscopic properties of tellurofluoroborate glasses containing Sm3+ ions

The effect of modifier oxide on the structural and optical properties of Sm3+ doped tellurofluoroborate glasses with the chemical composition (50-x)B2O3+xCaCO3+30TeO2+ 10ZnO+9ZnF2+1Sm2O3 have been studied by varying B2O3 and CaCO3 content. The fundamental stretching vibrations in the prepared glasses were investigated using FTIR and Raman spectral analysis. The optical behavior and the excited state energy transfer studies have been carried out by exploring the absorption, photoluminescence and decay spectra. The XRD spectrum was used to confirm the amorphous nature. The Nephelauxetic shift on the higher energy of the absorption spectra and the bonding parameter studies reveal the ionic nature of the Sm-O metal-ligand bond. Judd-Ofelt (JO) analysis have been used to determine branching ratio, radiative lifetime and emission cross-section of the reddish-orange emission originating from the 4G5/2 level to the 6H5/2, 6H7/2, 6H9/2 and 6H11/2 levels of the Sm3+ ion. The color of the emission has been demonstrated through CIE 1931 color chromaticity diagram. The non-exponential behavior of the 4G5/2 decay curves exhibit various energy transfer mechanism like non-radiative relaxation due to the multiphonons in the title glasses and the cross-relaxation among the Sm3+ ions. The increase in experimental lifetime of the 4G5/2 level with the addition of CaCO3 content is due to the reduction in the higher phonon energy and minimal absorption of OH free radicals. Among the prepared glasses, Sm20CTFB glass exhibit higher βR, σPE values pertaining to the 4G5/2→6H7/2 transition of the Sm3+ ions. The higher quantum efficiency (η), σPE×λeƒƒ and σPE×τR values for all the title glasses suggest that these glasses are good candidates for the realization of reddish-orange visible lasers and for the fabrication of photonic devices.