Structural and Optical Properties of NIR Laser Excited Ho³⁺/Yb³⁺ Doped Sr₂LaF₇ UC Phosphor

This article reported the synthesis and upconversion luminescence properties of Ho3+/Yb3+ co-doped Sr2LaF7 phosphors. It has been synthesized by the wet chemical method. The structural and morphological properties of the prepared phosphor were studied by XRD, SEM, and HRTEM analysis. UCL of Sr2LaF7: Ho3+/Yb3+ nanophosphors was observed in the visible to NIR range under 980-nm laser excitation. Thus, it exhibits intense green upconversion at 542 nm, and doublet red emission bands were observed at 645 and 653 nm, respectively. The emission intensities were enhanced by increasing the concentration of Ho3+ ions. Hence, nanocrystalline Sr2LaF7: Ho3+/Yb3+ is a promising host for bioimaging applications.