Efficient upconversion luminescence of Er3+:SrF2–SiO2–Al2O3 sol–gel glass ceramics

Er3+:SrF2–SiO2–Al2O3 transparent glass ceramic was prepared by a sol–gel method. The effect of Al3+ doping on the microstructures and luminescence properties of the materials was investigated by the X-ray diffraction (XRD), the transmission electron microscopy (TEM) and the absorption and luminescence spectra measurements. It was evident that Al3+ ions play an important role in improving the structure stability of the glass ceramic by suspending the crystallization of the oxide glassy matrix. The upconversion luminescence of the Al3+-doped glass ceramic was greatly enhanced and visible by the naked eyes, which implies the potential application of this material in the field of solid-state displays.