A novel synthesis method and up-conversion properties of hexagonal-phase NaYF4:Er nano-crystals

Chemical sensors based on periodic mesoporous organosilica @NaYF4:Ln3+ nanocomposites

“…As one of the most excellent upconversion nanoparticles (UCNPs), Ln 3+ -doped NaYF 4 was widely investigated in optical fields due to its low phonon energy, avoiding excessive losses from non-radiative relaxation. [12][13][14] Furthermore, UCNPs show many advantages including high luminescence intensity, superior chemical stability, low autofluorescence, enlarged signal-to-noise ratio, high detection sensitivity, and the ability of high penetration depth in biological or environmental samples without causing any significant photodamage to living cells. 15 Although the studies on UCNPs for sensing applications are abundant, some disadvantages still remain such as biocompatibility and water dispersability.…”

Upconversion luminescence in erbium doped transparent oxyfluoride glass ceramics containing hexagonal NaYF4 nanocrystals

“…Several groups have succeeded in the preparation of ␤-NaYF 4 in micro-and nanocrystalline form both in powders and in suspensions [22][23][24]. In 2006 a group of Wang have obtained a transparent OxFGC with Er 3+ doped ␣-NaYF 4 nanocrystals dispersed in aluminosilicate matrix [25].…”