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Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy

[Image: see text] Quantum dots (QDs) form a promising family of nanomaterials for various applications in optoelectronics. Understanding the details of the excited-state dynamics in QDs is vital for optimizing their function. We apply two-color 2D electronic spectroscopy to investigate CdSe QDs at 7...

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Autores principales: Wang, Zhengjun, Lenngren, Nils, Amarotti, Edoardo, Hedse, Albin, Žídek, Karel, Zheng, Kaibo, Zigmantas, Donatas, Pullerits, Tõnu
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2022
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8842281/
https://www.ncbi.nlm.nih.gov/pubmed/35089715
http://dx.doi.org/10.1021/acs.jpclett.1c04110
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author Wang, Zhengjun
Lenngren, Nils
Amarotti, Edoardo
Hedse, Albin
Žídek, Karel
Zheng, Kaibo
Zigmantas, Donatas
Pullerits, Tõnu
author_facet Wang, Zhengjun
Lenngren, Nils
Amarotti, Edoardo
Hedse, Albin
Žídek, Karel
Zheng, Kaibo
Zigmantas, Donatas
Pullerits, Tõnu
author_sort Wang, Zhengjun
collection PubMed
description [Image: see text] Quantum dots (QDs) form a promising family of nanomaterials for various applications in optoelectronics. Understanding the details of the excited-state dynamics in QDs is vital for optimizing their function. We apply two-color 2D electronic spectroscopy to investigate CdSe QDs at 77 K within a broad spectral range. Analysis of the electronic dynamics during the population time allows us to identify the details of the excitation pathways. The initially excited high-energy electrons relax with the time constant of 100 fs. Simultaneously, the states at the band edge rise within 700 fs. Remarkably, the excited-state absorption is rising with a very similar time constant of 700 fs. This makes us reconsider the earlier interpretation of the excited-state absorption as the signature of a long-lived trap state. Instead, we propose that this signal originates from the excitation of the electrons that have arrived in the conduction-band edge.
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spelling pubmed-88422812022-02-15 Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy Wang, Zhengjun Lenngren, Nils Amarotti, Edoardo Hedse, Albin Žídek, Karel Zheng, Kaibo Zigmantas, Donatas Pullerits, Tõnu J Phys Chem Lett [Image: see text] Quantum dots (QDs) form a promising family of nanomaterials for various applications in optoelectronics. Understanding the details of the excited-state dynamics in QDs is vital for optimizing their function. We apply two-color 2D electronic spectroscopy to investigate CdSe QDs at 77 K within a broad spectral range. Analysis of the electronic dynamics during the population time allows us to identify the details of the excitation pathways. The initially excited high-energy electrons relax with the time constant of 100 fs. Simultaneously, the states at the band edge rise within 700 fs. Remarkably, the excited-state absorption is rising with a very similar time constant of 700 fs. This makes us reconsider the earlier interpretation of the excited-state absorption as the signature of a long-lived trap state. Instead, we propose that this signal originates from the excitation of the electrons that have arrived in the conduction-band edge. American Chemical Society 2022-01-28 2022-02-10 /pmc/articles/PMC8842281/ /pubmed/35089715 http://dx.doi.org/10.1021/acs.jpclett.1c04110 Text en © 2022 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Wang, Zhengjun
Lenngren, Nils
Amarotti, Edoardo
Hedse, Albin
Žídek, Karel
Zheng, Kaibo
Zigmantas, Donatas
Pullerits, Tõnu
Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy
title Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy
title_full Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy
title_fullStr Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy
title_full_unstemmed Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy
title_short Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy
title_sort excited states and their dynamics in cdse quantum dots studied by two-color 2d spectroscopy
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8842281/
https://www.ncbi.nlm.nih.gov/pubmed/35089715
http://dx.doi.org/10.1021/acs.jpclett.1c04110
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