Novel Upconversion Behavior In Ho~(3+)-Doped Transparent Oxyfluoride Glass-Ceramics Containing NaYbF_4 Nanocrystals

摘要

Novel Ho~(3+) doped highly transparent NaYbF_4 glass-ceramics were successfully fabricated by melt-quenching technique. Their structural and luminescent properties were systemically investigated by XRD, TEM, absorption spectra, upconversion spectra, and lifetime measurements. Excited by 980-nm laser, samples exhibit characteristic emissions of Ho~(3+). Impressively, the luminescent color can be tuned easily from red for precursor glass to green for glass-ceramics. Such novel phenomenon was elaborately investigated and is owing to the reduced mul-tiphonon nonradiative relaxation and enhanced cross-relaxation of Ho~(3+) in NaYbF_4 nanocrystals after crystallization. Our results indicate that NaYbF_4 transparent glass-ceramics is an excellent host for upconversion.