Research Article
Efficient Color Tuning of Upconversion Luminescence from Core-Shell Oxysulfide Nanoparticles
Figure 3
Up-conversion emission spectra of Y2O2S: Yb3+, Er3+, Y2O2S: Yb3+, Ho3+, Y2O2S: Er3+ @ Y2O2S: Yb3+, Ho3+ and Y2O2S: Yb3+, Er3+, Ho3+ samples under 980 nm excitation.