Aerosol Flame Synthesis and Manipulating Upconversion Luminescence of Ultrasmall Y<sub>2</sub>O<sub>3</sub>:Yb<sup>3+</sup>/Ho<sup>3+</sup> Nanoparticles
oleh: Shuai Hu, Maohui Yuan, Linxuan Wang, Changqing Song, Zining Yang, Hongyan Wang, Kai Han
| Format: | Article |
|---|---|
| Diterbitkan: | IEEE 2022-01-01 |
Deskripsi
The synthesis of upconversion nanoparticles (UCNPs) by flame aerosol is of great significance to realize industrial large-scale production of UCNPs and develop nanotechnology further. Here, for the first time, we successfully fabricated the ultrasmall Y<sub>2</sub>O<sub>3</sub>:Yb<sup>3+</sup>/Ho<sup>3+</sup> UCNPs by a self-build swirl flame spray pyrolysis (SFSP) method with a high production rate of ∼40 g<inline-formula><tex-math notation="LaTeX">$ \cdot $</tex-math></inline-formula> h<sup>−1</sup>. These flame-made UCNPs are all pure cubic phases with an average ultrasmall size of ∼14 nm. Excited by 980 nm laser, the synthesized UCNPs show bright green (<sup>2</sup>F<sub>4</sub>, <sup>5</sup>S<sub>2</sub> → <sup>5</sup>I<sub>8</sub>) and relatively weak red (<sup>5</sup>F<sub>5</sub> → <sup>5</sup>I<sub>8</sub>) upconversion luminescence (UCL). Based on the UCL spectra of Y<sub>2</sub>O<sub>3</sub>:Yb<sup>3+</sup>/Ho<sup>3+</sup> UCNPs, the optimal doping concentrations of 6 mol% Yb<sup>3+</sup> and 0.1 mol% Ho<sup>3+</sup> were determined to reach the most intense UCL. The dependence of UCL intensity and pump power was further analyzed, and it indicated that the green and red UCL are two-photon processes. In addition, the UCL properties with different synthesized conditions were also demonstrated. The UCL mechanism of these flame-made Y<sub>2</sub>O<sub>3</sub>:Yb<sup>3+</sup>/Ho<sup>3+</sup> UCNPs were illustrated in detail. Our results prove that industrial large-scale production of continuous one-step synthesis of UCNPs by flame aerosol technology is completely feasible and deserves further study.