Exciton-Phonon Coupling in Single ZnCdSe-Dot/CdS-Rod Nanocrystals with Engineered Band Gaps from Type-II to Type-I.

Autor: Johst F; Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, Hamburg D-20416, Germany., Rebmann J; Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, Hamburg D-20416, Germany., Werners H; Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, Hamburg D-20416, Germany., Klemeyer L; Institute of Nanostructure and Solid State Physics, University of Hamburg, Luruper Chaussee 149, Hamburg D-22761, Germany., Kopula Kesavan J; Institute of Nanostructure and Solid State Physics, University of Hamburg, Luruper Chaussee 149, Hamburg D-22761, Germany., Koziej D; Institute of Nanostructure and Solid State Physics, University of Hamburg, Luruper Chaussee 149, Hamburg D-22761, Germany., Strelow C; Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, Hamburg D-20416, Germany., Bester G; Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, Hamburg D-20416, Germany.; The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, Hamburg 22761, Germany., Mews A; Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, Hamburg D-20416, Germany., Kipp T; Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, Hamburg D-20416, Germany.
Jazyk: angličtina
Zdroj: ACS photonics [ACS Photonics] 2024 Sep 06; Vol. 11 (9), pp. 3741-3749. Date of Electronic Publication: 2024 Sep 06 (Print Publication: 2024).
DOI: 10.1021/acsphotonics.4c00931
Abstrakt: Exciton-phonon coupling limits the homogeneous emission line width of nanocrystals. Hence, a full understanding of this is crucial. In this work, we statistically investigate exciton-phonon coupling by performing single-particle spectroscopy on colloidal Zn 1- x Cd x Se/CdS and CdSe/CdS dot-in-rod nanocrystals at cryogenic temperatures ( T ≈ 10 K). In situ cation exchange enables us to analyze different band alignments and, thereby, different charge-carrier distributions. We find that the relative intensities of the longitudinal optical S- and Se-type phonon replicas correlate with the charge-carrier distribution. Our experimental findings are complemented with quantum mechanical calculations within the effective mass approximation that hint at the relevance of surface charges.
Competing Interests: The authors declare no competing financial interest.
(© 2024 The Authors. Published by American Chemical Society.)
Databáze: MEDLINE
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