Multicolor Emission Tuning and Red/Green Ratio Enhancement of Yb³⁺/Er³⁺ Codoped KGdF₄ Upconversion Nanoparticles

Figure 4

The variation of R/G ratio of KGdF₄:Yb³⁺/Er³⁺ UCNPs as a function of Yb³⁺ concentration.