Effect of Yb3+ concentration on microstructure and optical properties of Yb: SrF2 transparent ceramics

Abstract

Ytterbium-doped strontium fluoride (Yb: SrF2) nanopowders with different amounts of Yb3+ were synthesized by a co-precipitation method. XRD and FE-SEM measurements were used to characterize the phase composition and morphologies of these nanopowders. The Yb: SrF2 nanopowders doped with 1–5 at.% Yb3+ showed the same phase as pure SrF2, with a mean particle size of 20 nm. Transparent Yb: SrF2 ceramics were fabricated by hot-pressing the nanopowders, and the transmittance of 1 at.% Yb: SrF2 with a thickness of 2 mm was 85% at 1200 nm. The absorption spectra, luminescence spectra, and luminescence decays of the ceramics were also obtained. As the Yb3+ doping amount increased, the absorption and emission intensities also increased, indicating the absence of a concentration quenching effect in the Yb: SrF2 ceramics. However, the decay lifetimes decreased with increasing Yb3+ content, and 1–5% Yb: SrF2 transparent ceramics had decay lifetimes of 4.58, 3.48, 3.22, and 3.19 ms, respectively.