Ultra Long-Lived Radiative Trap States in CdSe Quantum Dots

Mohamed Qenawy; Khadga Jung Karki; Nils Lenngren; Kaibo Zheng; Torbjörn Pascher; Arkady Yartsev; Tönu Pullerits

doi:10.1021/jp506536h

Ultra Long-Lived Radiative Trap States in CdSe Quantum Dots

Mohamed Qenawy, Khadga Jung Karki, Nils Lenngren, Kaibo Zheng, Torbjörn Pascher, Arkady Yartsev, Tönu Pullerits

Research output: Contribution to journal › Article › peer-review

Abstract

Surface states and traps play an important role in the photophysics of colloidal quantum dots. These states typically lead to large red-shifted photoluminescence. We have used steady-state and time-resolved spectroscopic techniques to investigate the nature of the traps and their lifetimes in colloidal CdSe quantum dots. We conclude that at least two different types of traps contribute to the photoluminescence. The trapping is more pronounced at higher excitation energies compared to the band edge excitation. Hole trapping is dominant in CdSe quantum dots. The time-resolved photoluminescence and pump–probe measurements show that the trapped holes live for longer than tens of microseconds at room temperature.

Original language	English
Pages (from-to)	21682-21686
Number of pages	5
Journal	Journal of Physical Chemistry C
Volume	118
Issue number	37
DOIs	https://doi.org/10.1021/jp506536h
Publication status	Published - 2014

Bibliographical note

Authors Mohamed Abdellah and Khadga Karki contributed equally to the article.

The information about affiliations in this record was updated in December 2015.
The record was previously connected to the following departments: Chemical Physics (S) (011001060)

Subject classification (UKÄ)

Atom and Molecular Physics and Optics

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10.1021/jp506536h

http://pubs.acs.org/doi/abs/10.1021/jp506536h

Cite this

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title = "Ultra Long-Lived Radiative Trap States in CdSe Quantum Dots",

abstract = "Surface states and traps play an important role in the photophysics of colloidal quantum dots. These states typically lead to large red-shifted photoluminescence. We have used steady-state and time-resolved spectroscopic techniques to investigate the nature of the traps and their lifetimes in colloidal CdSe quantum dots. We conclude that at least two different types of traps contribute to the photoluminescence. The trapping is more pronounced at higher excitation energies compared to the band edge excitation. Hole trapping is dominant in CdSe quantum dots. The time-resolved photoluminescence and pump–probe measurements show that the trapped holes live for longer than tens of microseconds at room temperature.",

author = "Mohamed Qenawy and Karki, {Khadga Jung} and Nils Lenngren and Kaibo Zheng and Torbj{\"o}rn Pascher and Arkady Yartsev and T{\"o}nu Pullerits",

note = "Authors Mohamed Abdellah and Khadga Karki contributed equally to the article. The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)",

year = "2014",

doi = "10.1021/jp506536h",

language = "English",

volume = "118",

pages = "21682--21686",

journal = "Journal of Physical Chemistry C",

issn = "1932-7447",

publisher = "The American Chemical Society (ACS)",

number = "37",

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TY - JOUR

T1 - Ultra Long-Lived Radiative Trap States in CdSe Quantum Dots

AU - Qenawy, Mohamed

AU - Karki, Khadga Jung

AU - Lenngren, Nils

AU - Zheng, Kaibo

AU - Pascher, Torbjörn

AU - Yartsev, Arkady

AU - Pullerits, Tönu

N1 - Authors Mohamed Abdellah and Khadga Karki contributed equally to the article. The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)

PY - 2014

Y1 - 2014

N2 - Surface states and traps play an important role in the photophysics of colloidal quantum dots. These states typically lead to large red-shifted photoluminescence. We have used steady-state and time-resolved spectroscopic techniques to investigate the nature of the traps and their lifetimes in colloidal CdSe quantum dots. We conclude that at least two different types of traps contribute to the photoluminescence. The trapping is more pronounced at higher excitation energies compared to the band edge excitation. Hole trapping is dominant in CdSe quantum dots. The time-resolved photoluminescence and pump–probe measurements show that the trapped holes live for longer than tens of microseconds at room temperature.

AB - Surface states and traps play an important role in the photophysics of colloidal quantum dots. These states typically lead to large red-shifted photoluminescence. We have used steady-state and time-resolved spectroscopic techniques to investigate the nature of the traps and their lifetimes in colloidal CdSe quantum dots. We conclude that at least two different types of traps contribute to the photoluminescence. The trapping is more pronounced at higher excitation energies compared to the band edge excitation. Hole trapping is dominant in CdSe quantum dots. The time-resolved photoluminescence and pump–probe measurements show that the trapped holes live for longer than tens of microseconds at room temperature.

U2 - 10.1021/jp506536h

DO - 10.1021/jp506536h

M3 - Article

SN - 1932-7447

VL - 118

SP - 21682

EP - 21686

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

IS - 37

ER -

Ultra Long-Lived Radiative Trap States in CdSe Quantum Dots

Abstract

Bibliographical note

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