LAUSR

Abstract Dy 3 + doped potassium aluminiumtelluroborate glasses with the chemical composition 55H 3 BO 3  + (20 − x)TeO 2  + 10K 2 CO 3  + 15Al 2 O 3  + xDy 2 O 3 (where x = 0, 0.05, 0.1, 0.25, 0.5, 1.0 and 2.0 in wt%) were prepared following the melt quenching technique and its structural and optical behavior were analyzed through recording FTIR, UV–Vis-NIR, luminescence and decay spectra. The FTIR spectra confirm the presence of different stretching and bending vibrations of B O and Te O network in the prepared glasses. The nephelauxetic ratios (β) and bonding parameter (δ) values were determined from the absorption spectra and these values confirms the increasing covalent nature. The Judd-Ofelt (JO) intensity parameters (Ω 2 , Ω 4 , Ω 6 ) have been determined and the Ω 2 parameter value is found to increase with the increase in Dy 3 + ions concentration thus indicates the increasing asymmetry nature. The luminescence spectra exhibits three distinguishable peaks at around 483 nm, 575 nm and 662 nm corresponding to the 4 F 9/2  →  6 H 15/2 , 4 F 9/2  →  6 H 13/2 and 4 F 9/2  →  6 H 11/2 transitions while exciting at 388 nm. The Y/B ratio which signifies the local field environment was found to increase with the increase in the concentration of Dy 3 + ions in the present glasses. The luminescence intensity of these transitions is found to quench beyond 0.5 wt% Dy 3 + ions concentration which may probably due to the occurrence of possible resonant energy transfer and cross-relaxation mechanisms. The decay measurements were made by monitoring an excitation at 388 nm and emission at 575 nm corresponding to the 4 F 9/2  →  6 H 13/2 transition and the decay curve exhibit single exponential behavior at lower concentration and turn to exhibit bi-exponential behavior beyond 0.1 wt% of Dy 3 + ion. Employing the Inokuti-Hirayama model, the type of interaction takes place between the donor-acceptor ions has been identified and the parameters like donor-acceptor interaction parameter (C DA ), critical distance (R 0 ) were also calculated and discussed. Among the prepared glasses, 0.5 wt% Dy 3 + ions doped glass was found to exhibit higher stimulated emission cross-section pertaining to the 4 F 9/2  →  6 H 13/2 transition thus suggests its suitability for yellow laser applications. The CIE color chromaticity coordinates (x,y) were determined following the standard Commission International de I'Eclairage (CIE) 1931 chromaticity diagram and the values were found to be in close proximity with the standard white light (0.33, 0.33) for all the prepared glasses thus suggests the suitability of the present glasses for white light generation. Further correlated color temperature (CCT) values were found to agree with the cool white light suggesting the suitability of these glasses for operating in schools, offices etc.