Nanoscale CaF2 doped with Eu3+ and Tb3+ through fluorolytic sol–gel synthesis

Abstract

In this article, the high potential of the fluorolytic sol–gel process to synthesize nanoscopic rare earth-doped calcium fluoride sols is shown. Through a fluorolytic sol–gel process we manage to achieve spherical monodisperse ∼5 nm sized nanoparticles using a simple and reproducible one-pot-wet chemical route at room temperature. The as-synthesized clear sols exhibit an intense red and green luminescence under UV excitation at room temperature. A spectroscopic study of the sols revealed the characteristic transitions ⁵D₀ → ⁷F_J of Eu³⁺ and ⁵D₄ → ⁷F_J of Tb³⁺, with ⁵D₀ → ⁷F₂ (611 nm) of Eu³⁺ and ⁵D₄ → ⁷F₄ (581 nm) of Tb³⁺ as the most prominent transitions. This facile synthetic strategy is also valuable for developing other luminescent nanoparticles.