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Time dependent study of multiple exciton generation in nanocrystal quantum dots

Damtie, Fikeraddis A. LU and Wacker, Andreas LU (2016) In Journal of Physics, Conference Series 696(1).
Abstract

We study the exciton dynamics in an optically excited nanocrystal quantum dot. Multiple exciton formation is more efficient in nanocrystal quantum dots compared to bulk semiconductors due to enhanced Coulomb interactions and the absence of conservation of momentum. The formation of multiple excitons is dependent on different excitation parameters and the dissipation. We study this process within a Lindblad quantum rate equation using the full many-particle states. We optically excite the system by creating a single high energy exciton ESX in resonance to a double exciton EDX. With Coulomb electron-electron interaction, the population can be transferred from the single exciton to the double exciton state by impact... (More)

We study the exciton dynamics in an optically excited nanocrystal quantum dot. Multiple exciton formation is more efficient in nanocrystal quantum dots compared to bulk semiconductors due to enhanced Coulomb interactions and the absence of conservation of momentum. The formation of multiple excitons is dependent on different excitation parameters and the dissipation. We study this process within a Lindblad quantum rate equation using the full many-particle states. We optically excite the system by creating a single high energy exciton ESX in resonance to a double exciton EDX. With Coulomb electron-electron interaction, the population can be transferred from the single exciton to the double exciton state by impact ionisation (inverse Auger process). The ratio between the recombination processes and the absorbed photons provide the yield of the structure. We observe a quantum yield of comparable value to experiment assuming typical experimental conditions for a 4 nm PbS quantum dot.

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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 Physics, Conference Series
volume
696
issue
1
publisher
IOP Publishing
external identifiers
  • Scopus:84964843205
ISSN
1742-6588
DOI
10.1088/1742-6596/696/1/012012
language
English
LU publication?
yes
id
1e7ef85f-212e-4bf8-a8d4-66e59a9c2278
date added to LUP
2016-06-28 11:11:12
date last changed
2017-02-19 04:39:18
@article{1e7ef85f-212e-4bf8-a8d4-66e59a9c2278,
  abstract     = {<p>We study the exciton dynamics in an optically excited nanocrystal quantum dot. Multiple exciton formation is more efficient in nanocrystal quantum dots compared to bulk semiconductors due to enhanced Coulomb interactions and the absence of conservation of momentum. The formation of multiple excitons is dependent on different excitation parameters and the dissipation. We study this process within a Lindblad quantum rate equation using the full many-particle states. We optically excite the system by creating a single high energy exciton E<sub>SX</sub> in resonance to a double exciton E<sub>DX</sub>. With Coulomb electron-electron interaction, the population can be transferred from the single exciton to the double exciton state by impact ionisation (inverse Auger process). The ratio between the recombination processes and the absorbed photons provide the yield of the structure. We observe a quantum yield of comparable value to experiment assuming typical experimental conditions for a 4 nm PbS quantum dot.</p>},
  articleno    = {012012},
  author       = {Damtie, Fikeraddis A. and Wacker, Andreas},
  issn         = {1742-6588},
  language     = {eng},
  month        = {04},
  number       = {1},
  publisher    = {IOP Publishing},
  series       = {Journal of Physics, Conference Series},
  title        = {Time dependent study of multiple exciton generation in nanocrystal quantum dots},
  url          = {http://dx.doi.org/10.1088/1742-6596/696/1/012012},
  volume       = {696},
  year         = {2016},
}