Dependence of the up-conversion emission of Li+ co-doped Y2O3:Er3+ films with dopant concentration

The effect of dopant concentration on the up-conversion emission, and in particular on the Er3+ related green and red emissions of spray pyrolysis deposited films of Y2O3:Er3+ co-doped with Li+, is reported. Er3+ concentrations in the films in the range of 1.1-5.6 at% (1.5-14 at% Er3+ in the spraying solution) were studied, as well as the effect of co-doping them with Li+. Large concentrations of Er3+ favor the red emission, especially for contents higher than 10 at% in the spraying solution. Li+ co-doping improves the green and red emissions up to 365 and 171 times, respectively, depending on the Er3+ and Li+ concentrations.