Quantitative relationship between microstructure and optical properties of Er3+-Yb3+ co-doped glass-ceramics containing pyrochlore-type crystalline phases

Abstract

Er3+-Yb3+ co-doped transparent glass-ceramics (GCs) containing Y2Ti2O7 crystalline phase were prepared by the melting crystallization method. The qualitative relationship between light transmittance and three-dimensional structure parameters of glass-ceramic was studied according to the principle of stereology under different heat treatment conditions. As indicated by the research results, the light transmittance decreased with the increase in the equivalent spherical diameter (D3S) and specific surface area per unit volume of the grains (SV). However, the light transmittance increased linearly with the increase in the discrete grains (SVP) and the mean free distance (λ). The up-conversion luminescence intensity was found to be most vigorous under Er3+ and Yb3+ doping concentrations of 0.5% and 0.9%, respectively, at 980 nm excitation. Considering the correlation between pump power and up-conversion emission intensity, the up-conversion luminescence mechanism was explored. As revealed by the results of color purity and chromaticity coordinates, Er3+-Yb3+ co-doped GCs containing Y2Ti2O7 have promising applications in green up-conversion luminescence.