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arXiv · 2404.11516

Exciton-Phonon Coupling in Single Band-Gap Engineered ZnCdSe-Dot/CdS-Rod Nanocrystals

Florian Johst·Jannik Rebmann·Hans Werners·Lars Klemeyer·Jagadesh Kopula Kesavan·Dorota Koziej·Christian Strelow·Gabriel Bester·Alf Mews·Tobias Kipp
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Abstract

Exciton-phonon coupling limits the homogeneous emission linewidth of nanocrystals. Hence, a full understanding of it is crucial. In this work, we statistically investigate exciton-phonon coupling by performing single-particle spectroscopy on Zn$_{1-x}$Cd$_{x}$Se/CdS dot-in-rod nanocrystals at cryogenic temperatures ($T\approx 10~\rm{K}$). 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.

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Florian Johst, Jannik Rebmann, Hans Werners, Lars Klemeyer, Jagadesh Kopula Kesavan, Dorota Koziej, Christian Strelow, Gabriel Bester, Alf Mews, Tobias Kipp. 2024-04-17. Exciton-Phonon Coupling in Single Band-Gap Engineered ZnCdSe-Dot/CdS-Rod Nanocrystals. https://arxiv.org/abs/2404.11516

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