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Seminarium Oddziału Fizykochemii Biomedycznej

09:00 piątek, 17-01-25
Microsoft Teams

Materials combinations for the synthesis of rare earth-based core-shell nanocrystals: improving SWIR imaging for biomedical application

dr Damien Hudry

Karlsruhe Institute of Technology Germany

The vast majority of rare-earth (RE) based core-shell nanocrystals developed for upconversion and downshifting rely on the combination of homogeneous domains such as ternary alkali metal fluorides (i.e.NaREF4). The latter, over the past two decades, have been widely investigated for the synthesis of a wide variety of single- and multi-shell structures. Nevertheless, with the rapid democratization of the synthesis of such archetypes, a number of fundamentals have been neglected such as for instance inter-domain cation intermixing during the shell growth process.1-3 Such a widely overlooked phenomenon, despite its detrimental effect on the real atomic scale organization and thus, available energy migration pathways, also prevented the discovery of radically different materials combinations with either improved and/or unconventional optical properties. For instance, the major benefit of heterostructures over homogeneous ones to prevent cation intermixing and improve short-wave infrared fluorescence has been recently demonstrated by our group.4,5 In this presentation, we will report on the use of quantitative methods such as energy dispersive spectroscopy and the quantitative analysis of high-resolution annular dark field scanning transmission electron microscopy images as well as powder x-ray diffraction to reveal the atomic-scale organization of different types of homogeneous and heterogeneous materials combinations for the synthesis of RE-based core-shell structures. Consequences regarding the control of energy migration pathways to tune optical characteristics will be described. Finally, an attempt will be made to classify materials combinations and synthesis techniques regarding their ability to form true core-shell structures.

  1. Hudry et al., Chem. Mater. 2017, 29, 9238.
  2. Hudry et al., J. Mater. Chem. C 2019, 7, 7371.
  3. Hudry et al., Small 2021, 17, 2104441.
  4. Hudry et al., Nature Commun. 2023, 14, 4462.
  5. Hudry et al., ACS Nano 2024, 18, 26233.

 

The seminar will be held remotely via the Microsoft Teams application. To participate in the event, please get in touch with Prof. Artur Bednarkiewicz.

Seminarium odbędzie się zdalnie w aplikacji Microsoft Teams. Osoby spoza INTiBS proszone są o kontakt z Prof. Arturem Bednarkiewiczem.

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