Synthesis and upconversion luminescence of YF3:Yb3+ Tm3+ and TiO2-coated YF3:Yb3+, Tm3+ microcrystals.

Upconversion luminescence properties of Yb3+, Gd3+, and Tm3+ co-doped NaYF4 microcrystals synthesized by the hydrothermal method.

Yb3+/Gd3+/Tm3+ co-doped prism-like NaYF4 microcrystals were synthesized through a facile ethylene diamine triacetic acid (EDTA)-assisted hydrothermal method. The microcrystals were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), upconversion (UC) emission spectra, and decay curve. After annealing in an argon atmosphere, the microcrystals emitted bright blue and int...

Frequency upconversion of Tm3+ and Yb3+ codoped YLiF4 synthesized by hydrothermal method

In this paper, YLiF4 codoped with Tm3+ and Yb3+ ions was synthesized by hydrothermal method. Yb3+ concentration is fixed at 1.5%, and Tm3+ concentration is changed from 0.1 to 0.4%. Intense upconversion luminescence is observed when the samples are excited by 980 nm. The dependence of upconversion luminescence on Tm3+ concentrations is presented. The results show that upconversion luminescence ...

Enhanced Upconversion Luminescence in Yb3+/Tm3+-Codoped Fluoride Active Core/Active Shell/Inert Shell Nanoparticles through Directed Energy Migration

The luminescence efficiency of lanthanide-doped upconversion nanoparticles is of particular importance for their embodiment in biophotonic and photonic applications. Here, we show that the upconversion luminescence of typically used NaYF₄:Yb3+30%/Tm3+0.5% nanoparticles can be enhanced by ~240 times through a hierarchical active core/active shell/inert shell (NaYF₄:Yb3+30%/Tm3+0.5%)/NaYbF₄/NaYF₄...

Comparison of ultraviolet upconversion luminescence between thin film and bulk of calcium fluoride co-doped with Yb3+/Tm3+ ions.

A calcium fluoride thin film co-doped with Yb3+/Tm3+ was deposited on Si substrates by the spin-coating method using trifluoroacetic acid as a fluorine source. The scanning electron microscopy (SEM) image of the sample showed that a thin film with some cracks was formed. After annealing, the cracks disappeared, and the film became thinner. The roughness of the thin film was about 150 nm, which ...

Energy transfer efficiency in YF3 nanocrystals: Quantifying the Yb3+ to Tm3+ infrared dynamics