Synthese von Kolloiden und redispergierbaren Pulvern stark lumineszierender LaPO4:Ce,Tb-Nanokristalle

Abstract

Die Synthese nanokristalliner Materialien in hochsiedenden, koordinierenden Lösungsmitteln wird immer populärer, da so hochkristalline Nanopartikel in wohlseparierter, kolloidaler Form erhalten werden können. [1] Die entscheidende Rolle spielt dabei die Koordination von Lösungsmittelmolekülen an den Partikeloberflächen, die zu Kolloiden mit sehr engen Teilchengröûenverteilungen führen kann, vorausgesetzt, ein Lösungsmittel geeigneter Koordinationsstärke wurde gefunden und Verfahrensparameter wie Konzentration und Temperatur wurden richtig gewählt. [2] Beispiele für diese Methode sind die Synthese von hochkristallinen Cadmiumchalcogenid- [1a] und TiO 2 -Nanoclustern [1b] in Trioctylphosphinoxid (TOPO) sowie von InP- [1c,d] und InAs-Nanoclustern [1e] in Trioctylphosphan (TOP). Auf ähnliche Weise können ZnSe-[1f] Fe 2 O 3 -, Mn 3 O 4 -und Cu 2 O-Nanocluster [1g] in langkettigen Alkylaminen hergestellt werden. Unsere Synthese Abbildung 4. Schematische Darstellung der verschiedenen Aromatizitätstypen und der jeweils zugehörigen diamagnetischen Abschirmung entlang der senkrecht zur Molekülebene stehenden, durch den Ringpunkt der Elektronendichte verlaufenden Achse z.

Nanoparticles, Proteins, and Nucleic Acids: Biotechnology Meets Materials Science

“…As a result of their lower toxicity, colloids made up of other materials such as the chemically stable, highly luminescent, and less toxic LaPO 4 :Ce,Tb nanocrystals [172] might provide a solution to this problem. As a result of their lower toxicity, colloids made up of other materials such as the chemically stable, highly luminescent, and less toxic LaPO 4 :Ce,Tb nanocrystals [172] might provide a solution to this problem.…”

Green‐Emitting CePO4:Tb/LaPO4 Core–Shell Nanoparticles with 70 % Photoluminescence Quantum Yield

“…=277 nm). The spectra consist mainly of four groups of signals, which correspond to the f–f transitions of the Tb 3+ ions, and a weak band in the UV region as a result of the d–f transitions of Ce 3+ 3f,g. The photoluminescence quantum yield of the CePO 4 :Tb core particles in Figure 1 is 43 % for the terbium emission (53 % if the Ce emission is taken into account) and depends on the surface treatment of the particles and the solvent as described earlier 3f.…”

Biofunctionalization of Fluorescent Rare‐Earth‐Doped Lanthanum Phosphate Colloidal Nanoparticles

“…An alternative class of colloidal NPs that are potentially promising for biolabeling studies are those based on rare‐earth‐doped lanthanum phosphates (LaPO 4 ). Recent work by Haase and co‐workers reported the synthesis of monodisperse fluorescent LaPO 4 NPs 14–16. These NPs, approximately 7 nm in size, have fluorescence that originates from their bulk properties—transitions between d and f electron states and their local symmetry—and is independent of their size 14–16.…”

“…Recent work by Haase and co‐workers reported the synthesis of monodisperse fluorescent LaPO 4 NPs 14–16. These NPs, approximately 7 nm in size, have fluorescence that originates from their bulk properties—transitions between d and f electron states and their local symmetry—and is independent of their size 14–16. The optical properties of the LaPO 4 NPs can also be tuned by the rare‐earth dopant used—different colors are available by varying the dopants used in their synthesis (e.g., Ce, Tb, Eu, Dy) 14–17.…”

“…The optical properties of the LaPO 4 NPs can also be tuned by the rare‐earth dopant used—different colors are available by varying the dopants used in their synthesis (e.g., Ce, Tb, Eu, Dy) 14–17. The high chemical stability, high quantum yield (up to 61 %),16 and expected low toxicity18 of these NPs make them potentially suitable for biological labeling applications. In addition, the application of rare‐earth‐doped LaPO 4 thin films (from micron‐sized powders) as coatings for luminescent lamps points to a high photostability of such materials 19.…”