Near-infrared photoluminescence properties of Er/Yb- and Ho/Yb-doped multicomponent silicate glass - The role of GeO2, Al2O3 and ZnO

We prepared multicomponent silicate glass, which contained components with different glass-forming abilities, such as GeO2, Al2O3 and ZnO, or different concentrations of glass-modifier oxide Na2O. The influence of the glass composition on the network structure and its effect on the photoluminescence properties of rare-earth ions were investigated. It was found that a change in the Na2O content significantly affects the network polymerisation, but its influence on the photoluminescence of RE ions is limited. The photoluminescence properties of RE ions were significantly influenced by the presence of different components, such as GeO2, Al2O3 and ZnO, which was attributed to changes in the local environment of RE ions. ZnO induced highest asymmetry of host matrix around the RE ions, which led to a strong and broad photoluminescence with short fluorescence lifetime, whereas the inclusion of Al2O3 and GeO2 led to highly symmetric matrix with narrow emission bands and longer decay.