These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Temperature-dependent upconversion luminescence and dynamics of NaYF4:Yb3+/Er3+ nanocrystals: influence of particle size and crystalline phase.
    Author: Yu W, Xu W, Song H, Zhang S.
    Journal: Dalton Trans; 2014 Apr 28; 43(16):6139-47. PubMed ID: 24577323.
    Abstract:
    Oleic acid-capped NaYF4:Yb(3+)/Er(3+) upconversion nanocrystals (UCNCs) with different sizes and crystalline phases were prepared, and their temperature-dependent upconversion luminescence (UCL) and dynamics were studied. It is interesting to observe that the temperature-dependent behavior of UCL for the β-phase (25 nm, 45 nm and bulk) and α-phase (<10 nm) UCNCs is quite different. The UCL intensity of Er(3+) ions of the β-phase NaYF4 demonstrates a maximum around 100 K, while the intensity of the α-phase quenches monotonously with elevated temperature (10-400 K). The intensity ratio of (2)H11/2-(4)I15/2 to (4)S3/2-(4)I15/2, RHS, increases solely with temperature for β-phase NaYF4, while for the α-phase sample, it demonstrates a complex and indeterminate variation as a function of temperature. In the β-phase samples, rising processes were observed in the dynamics of Er(3+) ions, while in the α-phase sample, no rising process was observed and the decay processes of Er(3+) ions were bi-exponential. The rationale for these different temperature-dependent UCL properties was explained carefully.
    [Abstract] [Full Text] [Related] [New Search]