The Study of Upconversion Emission Fine-Tuning in Lanthanide-Doped NaYF₄ Nanoparticles

We report upconversion emission multicolor tuning based on mixing two kinds of lanthanide-doped NaYF₄ nanoparticles. The upconversion emission can be continuously and precisely modulated by adjusting the ratio of the nanoparticles with Tm³⁺ and Er³⁺. The chromaticity coordinates of the mixed solution are calculated by upconversion fluorescence spectra, which presents linear variation under different mixing ratio. Moreover, the corresponding relational equations of chromaticity coordinate and concentration ratio are established. In this way, it is easier to achieve the desired chromaticity and provides a quantificational method to realize chrominance adjustment.