Concentration quenching effect on luminescent properties of Sm3+ ions doped ZnBiNaPSr glasses for photonic device applications

Abstract

Concentration variation of trivalent samarium (Sm3+) ions doped ZnBiNaPSr oxyfluoride glasses have been prepared by using the standard melt quenching technique. The spectroscopic properties were investigated with diffraction, surface morphology, structural, optical and luminescence studies. The glassy nature of the samples was observed by the XRD pattern. The morphological images with feasible irregularities and elemental mapping were observed by SEM with EDS. The various structural PO, P–O–P, O–P–O and P–O–H phosphate bonds along with OH− groups were obtained by FTIR spectroscopy. The obtained absorption spectra in the UV–Vis–NIR region (300–1700 nm) consist of a series of bands assigned to respective transitions. The tauc's plots were drawn to estimate the band gap energies for the direct and indirect allowed transitions and measured the Urbach energy. The oscillatory strengths (fcal and fexp) and bonding parameters (δ) of each f-f transition have been evaluated. The phenomenological intensity parameters (Ω2, Ω4 and Ω6) were estimated from the J-O theory. The radiative parameters such as AT, τ, βR, Δλeff and σ were evaluated from the emission transitions. The luminescence intensity quenching was observed for the higher concentrations (1.5 & 2.0 mol%) of samarium ion. The high intense transition 4G5/2 → 6H7/2 (598 nm) was observed to be most suitable for the intense red-orange emission. The color coordinates, CCT, color purity of the ZnBiNaPSr oxyfluoride glasses were obtained from the CIE 1931 diagram.