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Hot Excitons Cool in Metal Halide Perovskite Nanocrystals as Fast as CdSe Nanocrystals.
Strandell, Dallas P; Zenatti, Davide; Nagpal, Priya; Ghosh, Arnab; Dirin, Dmitry N; Kovalenko, Maksym V; Kambhampati, Patanjali.
Afiliación
  • Strandell DP; Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada.
  • Zenatti D; Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada.
  • Nagpal P; Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada.
  • Ghosh A; Department of Chemistry, McGill University, Montreal, H3A 0B8, Canada.
  • Dirin DN; Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
  • Kovalenko MV; Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
  • Kambhampati P; Empa-Swiss Federal Laboratories for Materials Science and Technology, 8600 Dubendorf, Switzerland.
ACS Nano ; 18(1): 1054-1062, 2024 Jan 09.
Article en En | MEDLINE | ID: mdl-38109401
ABSTRACT
The idea of phonon bottlenecks has long been pursued in nanoscale materials for their application in hot exciton devices, such as photovoltaics. Decades ago, it was shown that there is no quantum phonon bottleneck in strongly confined quantum dots due to their physics of quantum confinement. More recently, it was proposed that there are hot phonon bottlenecks in metal halide perovskites due to their physics. Recent work has called into question these bottlenecks in metal halide perovskites. Here, we compare hot exciton cooling in a range of sizes of CsPbBr3 nanocrystals from weakly to strongly confined. These results are compared to strongly confined CdSe quantum dots of two sizes and degrees of quantum confinement. CdSe is a model system as a ruler for measuring hot exciton cooling being fast, by virtue of its efficient Auger-assisted processes. By virtue of 3 ps time resolution, the hot exciton photoluminescence can now be directly observed, which is the most direct measure of the presence of hot excitons and their lifetimes. The hot exciton photoluminescence decays on nearly the same 2 ps time scale on both the weakly confined perovskite and the larger CdSe quantum dots, much faster than the 10 ps cooling predicted by transient absorption experiments. The smaller CdSe quantum dot has still faster cooling, as expected from quantum size effects. The quantum dots of perovskites show extremely fast hot exciton cooling, decaying faster than detection limits of <1 ps, even faster than the CdSe system, suggesting the efficiency of Auger processes in these metal halide perovskite nanocrystals and especially in their quantum dot form. These results across a range of sizes of nanocrystals reveal extremely fast hot exciton cooling at high exciton density, independent of composition, but dependent upon size. Hence these metal halide perovskite nanocrystals seem to cool heavily following quantum dot physics.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: ACS Nano Año: 2024 Tipo del documento: Article País de afiliación: Canadá Pais de publicación: Estados Unidos
Texto completo
Añadir a Mi BVS
Imprimir
XML
PubMed Links
Buscar en Google

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: ACS Nano Año: 2024 Tipo del documento: Article País de afiliación: Canadá Pais de publicación: Estados Unidos