BaCaLu2F10:Ln3+ (Ln = Eu, Dy, Tb, Sm, Yb/Er, Yb/Ho) spheres: ionic liquid-based synthesis and luminescence properties

Abstract

Alkaline earth metal rare earth fluoride BaCaLu₂F₁₀:Ln³⁺ (Ln = Eu, Dy, Tb, Sm, Yb/Er, Yb/Ho) submicrospheres with uniform morphology and size were synthesized via a facile ionic liquid-based hydrothermal route. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy were used to characterize the samples. The effect of synthetic conditions such as solvent amount, pH, reaction temperature and time on the morphology and size of the final materials was investigated, and a formation mechanism was proposed. The ultraviolet-to-visible down-conversion luminescence of BaCaLu₂F₁₀:Ln³⁺ (Ln = Eu, Dy, Tb, Sm), the up-conversion luminescence of BaCaLu₂F₁₀ : Ln³⁺ (Ln = Yb/Er, Yb/Ho), and also the doping site were studied. It was demonstrated that BaCaLu₂F₁₀ was suitable for being utilized as a luminescent host matrix.