Phase transformation and enhancement of luminescence in the Tb3+-Yb3+ co-doped oxyfluoride glass ceramics containing NaYF4 nanocrystals

摘要

Cubic-to-hexagonal phase transformation and enhancement of upconversion emission are simultaneously achieved by modifying the ratio of ZnO/Na2O content in the Tb3+-Yb3+ co-doped oxyflouride Zincatesilion glass ceramics containing NaYF4 nanocrystals. XRD and TEM data have revealed that the crystallization of NaYF4 from alpha phase to beta phase. Additionally, upconversion emissions were obtained from these Tb3+-Yb3+ glass ceramics under 980 nm excitation. Compared with the cubic alpha-NaYF4 nanocrystals of glass ceramics, the upconversion intensity augmented drastically owing to the phase transformation that the NaYF4 has changed from alpha into beta. Therefore, the PL results showed that the cubic-to-hexagonal the NaYF4:Eu3+ lattice could induce a remarkable change of the PL intensity in red region (R=I-ED/I-MD) with 393 nm excitation wavelength. It was indicated that it changed the phase transformation in Tb-Yb on symmetry of the lattice. (C) 2016 Elsevier Ltd. All rights reserved.