Photoluminescence of Yb³⁺/Ce³⁺ co-doped aluminosilicate glasses under ultraviolet irradiation

The photoluminescence and decay properties of Yb³⁺/Ce³⁺ co-doped aluminosilicate glasses were investigated under ultraviolet irradiation. A strong excitation band was ascribed to 4f → 5d transitions of Ce³⁺ ions. A broad ultraviolet-visible emission band belonged to 5d → 4f transitions of Ce³⁺ ions and oxygen-deficient centers (ODCs) in the host matrix, and the visible-near infrared emission band was attributed to non-bridging oxygen hole centers. Comparative tests of the core composition were performed. The results showed Yb₂O₃ and the ODCs played a crucial role on ultraviolet-visible emission band. ODCs rather than Ce³⁺ ions were responsible for the 1–35 μs lifetime decay of the ultraviolet-visible emission, but had no contribution to the longer decay lifetimes (77.58 μs) for Ce-free Yb³⁺-doped glasses. A complex schematic energy-level diagram including the electron transfer mechanism such as Ce³⁺-Yb³⁺ → Ce⁴⁺-Yb²⁺, the cooperative up- and down-conversion processes was proposed to describe different luminescence mechanisms UV-expose.