Spectroscopic characterization and up-conversion in sol–gel derived Yb3+–Pr3+ co-doped SiO2–LaF3 nano-glass-ceramics

The up-conversion of near infrared photons into the visible range is of major interest for lighting appliances and photonic integrated devices. Here we report up-conversion luminescence in transparent nano-glass-ceramics with composition of 95SiO2–5LaF3 co-doped with 0.1 mol% of Pr3+ and 0.3 mol% of Yb3+, which were synthesized by different thermal treatments of precursor sol–gel glasses. Precipitation of LaF3 nanocrystals during ceramming process was confirmed by means of X-ray diffraction and the partition of rare-earth ions into them has been analyzed. The effect of increasing thermal treatment temperature and adding Yb3+ ions in the degree of crystallinity of the samples has been discussed. Efficient up-conversion emissions were observed under infrared excitation of the Yb3+ ions in the co-doped Yb3+–Pr3+ samples, while it was hardly detected in single Pr3+-doped samples.