Evolution of Ag species and molecular-like Ag cluster sensitized Eu3+ emission in oxyfluoride glass for tunable light emitting

In this research, the EuF3-AgNO3 co-doped oxyfluoride glasses with varied fluoride content and monovalence cation were prepared by melt-quenching method. The optical absorption, photoluminescence and TEM measurement results indicated that the evolution of Ag species (including Ag+, molecular-like Ag clusters and Ag nanoparticles) is very sensitive to the original host composition. It is suggested that in the EuF3-AgNO3 co-doped system, the reduction of Ag+ ions into Ag atoms and the following aggregation process are not only closely related with the presence of the variable valence ions (Eu3+/2+) as reported previously, but also greatly affected by fluoride content and monovalence cation that constitute the host composition. The evolution of Ag species and the size distribution of the molecular-like Ag clusters can thus be controlled to benefit the efficient energy transfer from ML-Ag clusters to Eu3+. The obtained results also offered a convenient method to control the CIE coordinates in the EuF3-AgNO3 co-doped oxyfluoride glasses by slightly adjusting the glass composition. (C) 2016 Published by Elsevier B.V.