Figure 10
From: Morphology evolution and pure red upconversion mechanism of β-NaLuF4 crystals

UC emission spectra of β-NaLuF4:20% Yb3+, 1% Tm3+, 20% Er3+ crystals doped with different Li+ contents under 980 nm excitation.
From: Morphology evolution and pure red upconversion mechanism of β-NaLuF4 crystals

UC emission spectra of β-NaLuF4:20% Yb3+, 1% Tm3+, 20% Er3+ crystals doped with different Li+ contents under 980 nm excitation.