Synthesis and luminescence properties of NaGdF₄: Yb³⁺, Ce³⁺, and Ho³⁺ upconversion nanoparticles doped with Zn²⁺

Abstract

Due to shrinkage of crystal lattice and formation of F⁻ vacancies, the luminescence intensities show a rise-and-fall change with growing Zn²⁺ concentration in β-NaGdF₄ UCNPs.