Enhanced near-infrared emission in Yb3+-Cr3+ codoped KZnF3 glass ceramics excited by a solar simulator

Cr3+-Yb3+ codoped bulk glass-ceramics containing KZnF3 nanocrystals are fabricated by thermal treatment of cast glass samples and characterized by X-ray diffraction and transmission electron microscopy. The luminescent properties of the glass and glass ceramic are investigated from the measured photoluminescence spectra and fluorescent lifetime. The measurement results demonstrate that Cr3+ and Yb3+ ions are both predominantly hosted in the KZnF3 nanocrystals, and the energy absorbed by Cr3+ ions is efficiently transferred to Yb3+ ions when excited at 450 nm. Compared to the glass, the near-infrared emission in the Cr3+-Yb3+ codoped glass ceramics is significantly enhanced when the excitation wavelength lies in the range λ~400–800 nm of a solar simulator. Results indicate that the Cr3+-Yb3+ codoped KZnF3 glass ceramic provides a promising material for spectral conversion from visible sunlight to near-infrared emission and a novel gain material for solar pumped fiber laser.