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Ultra Long-Lived Radiative Trap States in CdSe Quantum Dots

Qenawy, Mohamed LU ; Karki, Khadga Jung LU ; Lenngren, Nils LU ; Zheng, Kaibo LU ; Pascher, Torbjörn LU ; Yartsev, Arkady LU and Pullerits, Tönu LU (2014) In Journal of Physical Chemistry C 118(37). p.21682-21686
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.
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physical Chemistry C
volume
118
issue
37
pages
21682 - 21686
publisher
The American Chemical Society
external identifiers
  • wos:000342118500042
  • scopus:84908608013
ISSN
1932-7447
DOI
10.1021/jp506536h
language
English
LU publication?
yes
id
0277a20b-7a6a-4470-8c6a-b2eb7a4991ad (old id 4698005)
alternative location
http://pubs.acs.org/doi/abs/10.1021/jp506536h
date added to LUP
2014-10-17 16:33:10
date last changed
2017-09-24 03:07:10
@article{0277a20b-7a6a-4470-8c6a-b2eb7a4991ad,
  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       = {Qenawy, Mohamed and Karki, Khadga Jung and Lenngren, Nils and Zheng, Kaibo and Pascher, Torbjörn and Yartsev, Arkady and Pullerits, Tönu},
  issn         = {1932-7447},
  language     = {eng},
  number       = {37},
  pages        = {21682--21686},
  publisher    = {The American Chemical Society},
  series       = {Journal of Physical Chemistry C},
  title        = {Ultra Long-Lived Radiative Trap States in CdSe Quantum Dots},
  url          = {http://dx.doi.org/10.1021/jp506536h},
  volume       = {118},
  year         = {2014},
}