Photoluminescence of Tb3+/Sm3+ ions co-activated in SrO - Na2O - WO3 - tellurite glasses for multicolor laser applications

A novel series of Tb³⁺, Sm³⁺ single doped and Tb³⁺/Sm³⁺ co-incorporated tungsten tellurite glasses were synthesized by melt quenching technique and corresponding structural as well as luminescence features of the prepared glasses have been reported here. Spectral overlapping between the luminescence spectra of Tb³⁺ ions and the excitation spectra of Sm³⁺ ions manifests that the energy transfer process takes place from Tb³⁺ ions to Sm³⁺ ions. By using the dual excitations at 377 and 484 nm, the titled co-doped glasses emit green light of wavelength 542 nm along with reddish – orange colour light at 599 nm. In addition to this, there is no possibility of reverse energy transfer which is validated with the help of excitation at 403 nm (Sm³⁺ ions) as major evidence. The lifetimes of all co-doped glasses decline with increasing Tb³⁺ doping level in the ligand matrices, indicating the energy migration process takes place from Tb³⁺→ Sm³⁺. The chromaticity coordinates of all synthesized co-doped glasses lie in yellowish-orange region of CIE1931 diagram and it shifts to deep yellow region when Tb³⁺ ion concentration varies. Our findings propose that the titled glasses can be used as visible laser materials for multicolor laser applications.