Investigation of spectroscopic properties of Sm-Eu codoped phosphate glasses

Phosphate glasses with chemical compositions of 74.5NaH(2)PO(4)-20ZnO-5Li(2)O-0.5Sm(2)O(3) and 74NaH(2)PO(4)-20ZnO-5Li(2)O-0.5Sm(2)O(3)-0.5Eu(2)O(3) were synthetized by melt quenching method. We investigated the influence of Sm3+/Eu3+ doping on the optical properties of phosphate glasses. X-ray Diffraction indicates that the samples have an amorphous structure. DSC measurements show a good thermal stability of phosphate glasses. Using the absorption spectra, Judd-Ofelt analysis was applied to absorption bands of Sm3+ (4f(5)) to carry out the three phenomenological parameters of Judd-Ofelt (JO). According to the obtained values of Omega(2), Omega(4) and Omega(6), some radiative properties were theoretically determined. We report both the photoluminescence (PL) and the PL lifetime measurements of a prominent emission transition (4)G(5/2) -> H-6(5/2) (604 nm) of Sm3+ both in absence and in presence of Eu3+. It is shown that Eu3+ ions act as sensitizers for Sm3+ ions and contribute largely to the improvement of the radiative properties of phosphate glasses. An improvement of the PL lifetime value after adding Eu3+ ions (4.58 ms) is reported. The predicted lifetime (tau(rad)) calculated by Judd-Ofelt theory and the experimental lifetime (tau(meas)) for the prepared phosphate glasses were compared with those of other works. Photoluminescence (PL) intensity of (4)G(5/2) -> H-6(5/2) (604 nm), (4)G(5/2) -> H-6(7/2) (567 nm), (4)G(5/2) -> H-6(9/2) (650 nm) and (4)G(5/2) -> H-6(11/2) (706 nm) and the quantum efficiency (eta) for the excited (4)G(5/2) level were enhanced after adding Eu3+. The radiative properties obtained for (Sm, Eu) codoped phosphate glasses suggest that the present material can be a potential candidate for the development of color display devices. (C) 2017 Elsevier B.V. All rights reserved.