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Ultrafast Dynamics of Multiple Exciton Harvesting in the CdSe-ZnO System: Electron Injection versus Auger Recombination.

Zidek, Karel LU ; Zheng, Kaibo LU ; Qenawy, Mohamed LU ; Lenngren, Nils LU ; Chabera, Pavel LU and Pullerits, Tönu LU (2012) In Nano Letters 12(12). p.6393-6399
Abstract
We study multiple electron transfer from a CdSe quantum dot (QD) to ZnO, which is a prerequisite for successful utilization of multiple exciton generation for photovoltaics. By using ultrafast time-resolved spectroscopy we observe competition between electron injection into ZnO and quenching of multiexcitons via Auger recombination. We show that fast electron injection dominates over biexcitonic Auger recombination and multiple electrons can be transferred into ZnO. A kinetic component with time constant of a few tens of picoseconds was identified as the competition between injection of the second electron from a doubly excited QD and a trion Auger recombination. Moreover, we demonstrate that the multiexciton harvesting efficiency changes... (More)
We study multiple electron transfer from a CdSe quantum dot (QD) to ZnO, which is a prerequisite for successful utilization of multiple exciton generation for photovoltaics. By using ultrafast time-resolved spectroscopy we observe competition between electron injection into ZnO and quenching of multiexcitons via Auger recombination. We show that fast electron injection dominates over biexcitonic Auger recombination and multiple electrons can be transferred into ZnO. A kinetic component with time constant of a few tens of picoseconds was identified as the competition between injection of the second electron from a doubly excited QD and a trion Auger recombination. Moreover, we demonstrate that the multiexciton harvesting efficiency changes significantly with QD size. Within a narrow QD diameter range from 2 to 4 nm, the efficiency of electron injection from a doubly excited QD can vary from 30% to 70% in our system. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nano Letters
volume
12
issue
12
pages
6393 - 6399
publisher
The American Chemical Society
external identifiers
  • wos:000312122100058
  • pmid:23163524
  • scopus:84870876642
ISSN
1530-6992
DOI
10.1021/nl303746d
language
English
LU publication?
yes
id
eb935861-3f3c-43a6-a9ba-f9026b92c933 (old id 3218823)
date added to LUP
2012-12-14 12:08:09
date last changed
2017-11-19 04:00:44
@article{eb935861-3f3c-43a6-a9ba-f9026b92c933,
  abstract     = {We study multiple electron transfer from a CdSe quantum dot (QD) to ZnO, which is a prerequisite for successful utilization of multiple exciton generation for photovoltaics. By using ultrafast time-resolved spectroscopy we observe competition between electron injection into ZnO and quenching of multiexcitons via Auger recombination. We show that fast electron injection dominates over biexcitonic Auger recombination and multiple electrons can be transferred into ZnO. A kinetic component with time constant of a few tens of picoseconds was identified as the competition between injection of the second electron from a doubly excited QD and a trion Auger recombination. Moreover, we demonstrate that the multiexciton harvesting efficiency changes significantly with QD size. Within a narrow QD diameter range from 2 to 4 nm, the efficiency of electron injection from a doubly excited QD can vary from 30% to 70% in our system.},
  author       = {Zidek, Karel and Zheng, Kaibo and Qenawy, Mohamed and Lenngren, Nils and Chabera, Pavel and Pullerits, Tönu},
  issn         = {1530-6992},
  language     = {eng},
  number       = {12},
  pages        = {6393--6399},
  publisher    = {The American Chemical Society},
  series       = {Nano Letters},
  title        = {Ultrafast Dynamics of Multiple Exciton Harvesting in the CdSe-ZnO System: Electron Injection versus Auger Recombination.},
  url          = {http://dx.doi.org/10.1021/nl303746d},
  volume       = {12},
  year         = {2012},
}