Red light generation through the lead boro telluro phosphate glasses activated by Eu3+ ions
Abstract Lead boro telluro phosphate glasses containing 0.05 to 2.0 wt% of Eu 3+ ions were prepared through melt quenching technique. Structural characteristics of title glasses were identified through XRD, FTIR and Raman studies. The optical properties of the prepared glasses were studied using UV Vis NIR absorption and photoluminescence spectra. From the resultant spectra, we have obtained the bonding parameters (d) nephelauxetic ratio (b) direct and indirect band gaps and Urbach energy (DE) values. A deep red luminescence due to 5 D 0 7 F 2 transition of Eu 3+ ions could be observed for the title glasses. The local site symmetry around the Eu 3+ ions and the degree of Eu 3+ O 2 covalence were assessed from the luminescence intensity ratio of 5 D 0 7 F 2 5 D 0 7 F 1 transitions. Judd Ofelt intensity parameters, calculated from the luminescence spectra, were used to estimate the radiative parameters like transition probability (A) branching ratio (b exp b cal and stimulated emission cross section s P E concerning the 5 D 0 7 F J (J 0, 1, 2, 3 and 4) transitions. The important laser parameters, gain bandwidth and optical gain are also estimated. The decay curves associated with the transition from 5 D 0 state was found to be single exponential at all Eu 3+ ion concentrations. CIE colour coordinates and colour purity of the prepared glasses were estimated from the CIE chromaticity diagram.