Up-conversion luminescence and near-infrared quantum cutting of Ho 3+ /Yb 3+ co-doped hexagonal NaGdF 4 phosphors

In this paper, Ho 3+ /Yb 3+ co-doped Sodium Gadolinium Fluoride (NaGdF 4 ) phosphors were synthesized by a facile and efficient hydrothermal method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy spectrum (EDS), and photoluminescence (PL). The results of XRD and SEM indicated that the prepared NaGdF 4 samples have the hexagonal structure and good orientation in the case of changing the concentration of Yb 3+ . The results of pump power dependence of up-conversion intensity indicated that the energy transfer mechanism from Yb 3+ to Ho 3+ is a two-photon process. The energy transfer between Ho 3+ and Yb 3+ under 448 nm excitation was determined by PL spectra and fluorescence lifetimes. All the results proved that the doping of Yb 3+ ions can effectively improve the up-conversion luminescence of NaGdF 4 phosphors and achieve quantum cutting efficiency of up to 179.8%. Overall, NaGdF 4 :Ho 3+ /Yb 3+ have potential application in the field of optoelectronic materials.