NaYF4:Yb,Er/NaYF4 Core/Shell Nanocrystals with High Upconversion Luminescence Quantum Yield
Autor(en): | Homann, Christian Krukewitt, Lisa Frenzel, Florian Grauel, Bettina Wuerth, Christian Resch-Genger, Ute Haase, Markus |
Stichwörter: | CANCER-THERAPY; Chemistry; Chemistry, Multidisciplinary; CORE; DOPED NANOPARTICLES; luminescence; nanocrystals; NANOMATERIALS; NANOSTRUCTURES; NaYF4; OPTICAL-PROPERTIES; PARTICLE-SIZE DISTRIBUTION; quantum yield; SHELL NANOPARTICLES; SURFACE MODIFICATION; upconversion; UPCONVERTING NANOPARTICLES | Erscheinungsdatum: | 2018 | Herausgeber: | WILEY-V C H VERLAG GMBH | Journal: | ANGEWANDTE CHEMIE-INTERNATIONAL EDITION | Volumen: | 57 | Ausgabe: | 28 | Startseite: | 8765 | Seitenende: | 8769 | Zusammenfassung: | Upconversion core/shell nanocrystals with different mean sizes ranging from 15 to 45nm were prepared via a modified synthesis procedure based on anhydrous rare-earth acetates. All particles consist of a core of NaYF4:Yb,Er, doped with 18% Yb3+ and 2% Er3+, and an inert shell of NaYF4, with the shell thickness being equal to the radius of the core particle. Absolute measurements of the photoluminescence quantum yield at a series of different excitation power densities show that the quantum yield of 45nm core/shell particles is already very close to the quantum yield of microcrystalline upconversion phosphor powder. Smaller core/shell particles prepared by the same method show only a moderate decrease in quantum yield. The quantum yield of 15nm core/shell particles, for instance, is reduced by a factor of three compared to the bulk upconversion phosphor at high power densities (100Wcm(-2)) and by approximately a factor of 10 at low power densities (1Wcm(-2)). |
ISSN: | 14337851 | DOI: | 10.1002/anie.201803083 |
Zur Langanzeige
Seitenaufrufe
2
Letzte Woche
0
0
Letzter Monat
0
0
geprüft am 17.05.2024