Thermal, structural and optical behaviour of Eu3+ ions in Zinc Alumino Boro-Silicate glasses for bright red emissions

Abstract

In present work we report the thermal, structural and optical behaviour of 20SiO2-(20-x) B2O3–10Al2O3–10ZnO–30NaF–10ZnF2-xEu2O3 glass system where Eu2O3 ions is doped in different molar concentrations (x = 0.1, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %). The Differential thermal analysis measurement was employed to study the thermal stability of the glasses through various thermal parameters such as Dietzel factor (ΔT), Hruby's parameter (KH), Weinberg Parameter (KW) and Lu and Liu Parameter (KLL). FTIR studies exhibit the presence of BO3, BO4, SiO2 vibrational units and the deconvoluted peak areas is used for the calculation of bridging and non-bridging oxygens. From the absorption spectra, the indirect bandgap energy (Eg) and Urbach's energy (EU) of the glasses have been calculated. Judd-Ofelt (JO) intensity parameters (Ω2 and Ω6) have been evaluated from the emission spectrum. The radiative parameters such as radiative transition probability (AR), branching ratio (βR), stimulated emission cross-section (σse) and radiative lifetimes (τR) were obtained using the JO parameters for the transitions 5D0→7F1,2,4 of Eu3+ ions. The decay life time of the 5D0 level is found to be single-exponential for all the Eu3+ doped glasses. An increase in lifetime values for the prepared glasses was found with increase in Eu3+ concentration from 0.1 mol% to 2.0 mol%. The colour chromaticity values and CCT values show the bright red emission from the prepared glasses.