Structure and up-conversion emission of Er~(3+)/Yb~(3+)-doped 5B_2O_3-5SrO-90SiO_2 nanostructured glass and glass-ceramics

摘要

Er~(3+) simply doped or Er~(3+)/Yb~(3+) co-doped transparent glass and glass-ceramics (GCs) were synthesized by a sol-gel method by controlling the heat treatment temperature. Their structure by X-ray diffraction (XRD), transmission electron microscope (TEM), energy-dispersive spectroscopy (EDS) and up-conversion luminescence (UCL) was systemically researched. The XRD results show that the nanocrystals are formed after heat treatment. The Raman spectra of GCs show that the sample processes symmetric breathing vibrations of boroxol rings. The TEM images indicate that some nanocrystalline particles in GCs are observed in the SiO_2 glass matrix. Under 980 nm excitation, the UCL is discovered in all samples by efficient energy transfer from Yb~(3+) to Er~(3+). Via the Ln-ln plots of the UCL emission intensity, the two-photon process is confirmed.