2 research outputs found
Upconversion Effective Enhancement by Producing Various Coordination Surroundings of Rare-Earth Ions
In this manuscript, we present a
simple route to enhance upconversion
(UC) emission by producing two different coordination sites of trivalent
cations in a matrix material and adjusting crystal field asymmetry
by Hf<sup>4+</sup> co-doping. A cubic phase, Y<sub>3.2</sub>Al<sub>0.32</sub>Yb<sub>0.4</sub>Er<sub>0.08</sub>F<sub>12</sub>, with these
structural characteristics was synthesized successfully by introducing
a small ion (Al<sup>3+</sup>) into YF<sub>3</sub>. X-ray diffraction
(XRD), nuclear magnetic resonance (NMR), transmission electron microscopy
(TEM), X-ray spectroscopy (XPS), and fluorescence spectrophotometry
(FS) were employed for its crystalline structure and luminescent property
analysis. As a result, the coordination environments of the rare-earth
ions were varied more obviously than a hexagonal NaYF<sub>4</sub> matrix
with the same Hf<sup>4+</sup> co-doping concentration, with vertical
comparison, UC luminescent intensities of cubic Y<sub>3.2</sub>Al<sub>0.32</sub>Yb<sub>0.4</sub>Er<sub>0.08</sub>F<sub>12</sub> were largely
enhanced (∼32–80 times greater than that of different
band emissions), while the maximum enhancement of hexagonal NaYF<sub>4</sub> was by a factor of ∼12. According to our experimental
results, the mechanism has been demonstrated involving the crystalline
structure, crystal field asymmetry, luminescence lifetime, hypersensitive
transition, and so on. The study may be helpful for the design and
fabrication of high-performance UC materials
Upconversion Effective Enhancement by Producing Various Coordination Surroundings of Rare-Earth Ions
In this manuscript, we present a
simple route to enhance upconversion
(UC) emission by producing two different coordination sites of trivalent
cations in a matrix material and adjusting crystal field asymmetry
by Hf<sup>4+</sup> co-doping. A cubic phase, Y<sub>3.2</sub>Al<sub>0.32</sub>Yb<sub>0.4</sub>Er<sub>0.08</sub>F<sub>12</sub>, with these
structural characteristics was synthesized successfully by introducing
a small ion (Al<sup>3+</sup>) into YF<sub>3</sub>. X-ray diffraction
(XRD), nuclear magnetic resonance (NMR), transmission electron microscopy
(TEM), X-ray spectroscopy (XPS), and fluorescence spectrophotometry
(FS) were employed for its crystalline structure and luminescent property
analysis. As a result, the coordination environments of the rare-earth
ions were varied more obviously than a hexagonal NaYF<sub>4</sub> matrix
with the same Hf<sup>4+</sup> co-doping concentration, with vertical
comparison, UC luminescent intensities of cubic Y<sub>3.2</sub>Al<sub>0.32</sub>Yb<sub>0.4</sub>Er<sub>0.08</sub>F<sub>12</sub> were largely
enhanced (∼32–80 times greater than that of different
band emissions), while the maximum enhancement of hexagonal NaYF<sub>4</sub> was by a factor of ∼12. According to our experimental
results, the mechanism has been demonstrated involving the crystalline
structure, crystal field asymmetry, luminescence lifetime, hypersensitive
transition, and so on. The study may be helpful for the design and
fabrication of high-performance UC materials