Short-wavelength upconversion luminescence of Yb3+/Tm3+ co-doped glass ceramic containing SrF2 nanocrystals

The preparation process and upconversion luminescence properties of the Yb3+ and Tm3+ co-doped glass ceramic containing SrF2 nanocrystals were investigated. In the glass ceramic, the SrF2 nanocrystals were embedded uniformly in the glass matrix. The Yb3+ and Tm3+ ions could be enriched into the precipitated SrF2 nanocrystalline phase, which provide much lower phonon energy than the glass matrix. The glass ceramic exhibited much stronger upconversion luminescence from ultraviolet to visible than the precursor glass. The upconversion luminescence mechanisms were mainly attributed to Yb3+–Yb3+ cooperative upconversion, Yb3+–Tm3+ energy transfer and Tm3+–Tm3+ cross relaxation.