Emission Spectra of Zinc Oxychloride Tellurite Glass: Effects of Eu3+/Sm3+ Co-Doping

Eu3+ or/and Sm3+ co-doped glasses based on TeO2-ZnO-ZnCl2-Li2O are prepared using the melt quenching technique and the effects of co-doping on the emission spectra of these glasses are examined. The Sm3+ doped glass under 403 nm excitations show emission bands around 561, 598 and 642 nm corresponding to the transitions of (4)G(5/2)-> H-6(5/2), (4)G(5/2)-> H-6(7/2) and (4)G(5/2 ->)(6)H(9/2) respectively. Whereas, in Eu3+ doped glass under 397 nm excitation emission bands appear around 553, 586, 613, 650 and 699 nm that corresponds to the transitions of D-5(1)-> F-7(2), D-5(0)-> F-7(1), D-5(0)-> F-7(2), D-5(0)-> F-7(3) and D-5(0)-> F-7(4). In addition, the emission spectra of the Eu3+/Sm3+ co-doped glass under 482 nm excitation consists of five bands in which three are contributed by Sm3+ at 561, 598 and 642 nm and two by Eu3+ at 613 nm and 699 nm respectively. Surprisingly, the emission bands of Eu3+ are still observed in the emission spectra of Sm3+ for the Eu3+/Sm3+ co-doped glasses despite the absence of the excitation wavelength 482 nm in the absorption and excitation domain of Eu3+. This observation is attributed to the partial resonance transfer of the absorption energy from Sm3+ to the Eu3+ ions.