Down- and up-conversion emissions in Er-doped transparent fluorotellurite glass-ceramics

10 págs.; 11 figs.; invited paperIn this work, we report the near infrared and upconversion emissions of Er3+-doped transparent fluorotellurite glass- ceramics obtained by heat treatment of the precursor Er-doped TeO2-ZnO-ZnF2 glass. Structural analysis shows that ErF3 nanocrystals nucleated in the glass-ceramic sample are homogeneously distributed in the glass matrix with a typical size of 45±10 nm. The comparison of the fluorescence properties of Er3+-doped precursor glass and glass-ceramic confirms the successful incorporation of the rare-earth into the nanocrystals. An enhancement of the red upconversion emission due to 4F9/2¿4I15/2 transition together with weak emission bands due to transitions from 2H9/2, 4F3/2,5/2, and 4F7/2 levels to the ground state are observed under excitation at 801 nm in the glass-ceramic sample. The temporal evolution of the red emission together with the excitation upconversion spectrum suggest that energy transfer processes are responsible for the enhancement of the red emission. © 2015 SPIEWe deeply acknowledge A. Ruiz-Caridad from the Laboratory of Electron Nanoscopies (LENS, University of Barcelona) and A. Tomas from the National Centre for Metallurgical Research (CENIM, CSIC) for HRTEM and EDX analysis, respectively. This work was supported by the Spanish Government MEC under Projects No. TEC2012-38901- C02-01, FIS2011-27968, MAT2013-48246-C2-2-P and Basque Country Government IT-659-13. A. Miguel and R. Morea acknowledge FPI grants from the Spanish Government.Peer Reviewe