Enhanced upconverted emission in Yb3+/Er3+ co-doped GdPO4 transparent glass ceramics

Yb3+/Er3+ co-doped transparent glass ceramics (GC) containing GdPO4 nanocrystals have been successfully fabricated using a conventional melt-quenching method with subsequent heat treatment. The structural and the luminescence properties were investigated by X-ray diffraction, transmission electron microscopy, and upconverted emission spectra. Under the excitation of a 980 nm diode laser, the total upconverted emission in GC as well as the Green/Red emission intensity ratio in the GC670 sample was enhanced compared to that in the precursor glass, indicating that Er3+ ions have entered into GdPO4 nanocrystals after crystallization. Our results also show that the Green/Red emission intensity ratio of GC is closely related to crystallinity of the samples. The outstanding properties of GdPO4-based transparent GC provide a promising candidate for wide application fields, such as in all-solid-state upconversion lasers and optical fibers.