Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy
Wang, Zhengjun LU ; Lenngren, Nils LU ; Amarotti, Edoardo LU ; Hedse, Albin LU ; Žídek, Karel LU ; Zheng, Kaibo LU ; Zigmantas, Donatas LU
and Pullerits, Tõnu
LU
(2022)
In Journal of Physical Chemistry Letters
13(5).
p.1266-1271
- Abstract
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... (More)
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.
(Less)
- author
- Wang, Zhengjun
LU
; Lenngren, Nils
LU
; Amarotti, Edoardo
LU
; Hedse, Albin
LU
; Žídek, Karel
LU
; Zheng, Kaibo
LU
; Zigmantas, Donatas
LU
and Pullerits, Tõnu
LU
- organization
- publishing date
- 2022-02-10
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Physical Chemistry Letters
- volume
- 13
- issue
- 5
- pages
- 6 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:85124085591
- pmid:35089715
- ISSN
- 1948-7185
- DOI
- 10.1021/acs.jpclett.1c04110
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: ©
- id
- 4f17cf94-f491-422b-a259-0942f100c8e4
- date added to LUP
- 2022-03-21 11:25:58
- date last changed
- 2025-01-16 07:47:41
@article{4f17cf94-f491-422b-a259-0942f100c8e4,
abstract = {{<p>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. </p>}},
author = {{Wang, Zhengjun and Lenngren, Nils and Amarotti, Edoardo and Hedse, Albin and Žídek, Karel and Zheng, Kaibo and Zigmantas, Donatas and Pullerits, Tõnu}},
issn = {{1948-7185}},
language = {{eng}},
month = {{02}},
number = {{5}},
pages = {{1266--1271}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Journal of Physical Chemistry Letters}},
title = {{Excited States and Their Dynamics in CdSe Quantum Dots Studied by Two-Color 2D Spectroscopy}},
url = {{http://dx.doi.org/10.1021/acs.jpclett.1c04110}},
doi = {{10.1021/acs.jpclett.1c04110}},
volume = {{13}},
year = {{2022}},
}