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Time-resolved terahertz spectroscopy reveals the influence of charged sensitizing quantum dots on the electron dynamics in ZnO

N., Sesha Bamini; Němec, Hynek; Zidek, Karel LU ; Abdellah, Mohamed LU ; Al-Marri, Mohammed J.; Chábera, Pavel LU ; Ponseca, Carlito LU ; Zheng, Kaibo LU and Pullerits, Tönu LU (2017) In Physical Chemistry Chemical Physics 19(8). p.6006-6012
Abstract

Photoinitiated charge carrier dynamics in ZnO nanoparticles sensitized by CdSe quantum dots is studied using transient absorption spectroscopy and time-resolved terahertz spectroscopy. The evolution of the transient spectra shows that electron injection occurs in a two-step process, where the formation of a charge transfer state (occurring in several picoseconds) is followed by its dissociation within tens of picoseconds. The photoconductivity of electrons injected into the ZnO nanoparticles is lower than that of charges photogenerated directly in ZnO. We conclude that the motion of injected electrons in ZnO nanoparticles is strongly influenced by their interaction with positive charges left in the sensitizing quantum dots.

Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Chemistry Chemical Physics
volume
19
issue
8
pages
7 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:85015070944
  • wos:000395869500034
ISSN
1463-9076
DOI
10.1039/c6cp07509f
language
English
LU publication?
yes
id
2c383447-7ded-4871-be20-0915b73a39f5
date added to LUP
2017-03-23 12:09:45
date last changed
2018-01-07 11:56:49
@article{2c383447-7ded-4871-be20-0915b73a39f5,
  abstract     = {<p>Photoinitiated charge carrier dynamics in ZnO nanoparticles sensitized by CdSe quantum dots is studied using transient absorption spectroscopy and time-resolved terahertz spectroscopy. The evolution of the transient spectra shows that electron injection occurs in a two-step process, where the formation of a charge transfer state (occurring in several picoseconds) is followed by its dissociation within tens of picoseconds. The photoconductivity of electrons injected into the ZnO nanoparticles is lower than that of charges photogenerated directly in ZnO. We conclude that the motion of injected electrons in ZnO nanoparticles is strongly influenced by their interaction with positive charges left in the sensitizing quantum dots.</p>},
  author       = {N., Sesha Bamini and Němec, Hynek and Zidek, Karel and Abdellah, Mohamed and Al-Marri, Mohammed J. and Chábera, Pavel and Ponseca, Carlito and Zheng, Kaibo and Pullerits, Tönu},
  issn         = {1463-9076},
  language     = {eng},
  number       = {8},
  pages        = {6006--6012},
  publisher    = {Royal Society of Chemistry},
  series       = {Physical Chemistry Chemical Physics},
  title        = {Time-resolved terahertz spectroscopy reveals the influence of charged sensitizing quantum dots on the electron dynamics in ZnO},
  url          = {http://dx.doi.org/10.1039/c6cp07509f},
  volume       = {19},
  year         = {2017},
}