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Effect of Submonolayer ZnS Shell on Biexciton Dynamics of Indium Phosphide Quantum Dots

Meng, Jie LU ; Zhao, Qian ; Lin, Weihua LU ; Pullerits, Tönu LU and Zheng, Kaibo LU (2023) In Advanced Electronic Materials 9(12).
Abstract

Understanding high-order biexciton dynamics is important for the use of semiconductor quantum dots (QDs) in optoelectronic devices. The core–shell structure can be used to modulate biexciton dynamics by varying the shell thickness and core–shell energy band alignment. In this study, the biexciton dynamics in an unconventional case in which each QD is encapsulated by a submonolayer shell are demonstrated. The result of a transient absorption spectroscopic study shows that InP/ZnS core/shell QDs with submonolayer shell coverage exhibit a prolonged Auger lifetime. However, the QD size dependence of the Auger recombination time features two constant distinct stages instead of the typical monotonic volume scaling law in conventional QDs. It... (More)

Understanding high-order biexciton dynamics is important for the use of semiconductor quantum dots (QDs) in optoelectronic devices. The core–shell structure can be used to modulate biexciton dynamics by varying the shell thickness and core–shell energy band alignment. In this study, the biexciton dynamics in an unconventional case in which each QD is encapsulated by a submonolayer shell are demonstrated. The result of a transient absorption spectroscopic study shows that InP/ZnS core/shell QDs with submonolayer shell coverage exhibit a prolonged Auger lifetime. However, the QD size dependence of the Auger recombination time features two constant distinct stages instead of the typical monotonic volume scaling law in conventional QDs. It is attributed to the tradeoff between the enlarged QD size and quantum-well confinement for the Auger processes. However, the abrupt change between the two stages is due to the change in the shell coverage. This study provides a reference for the application of core–shell QDs in optoelectronic devices in which full coverage of the shell is not achieved.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
auger recombination, biexciton, indium phosphide, quantum dots, submonolayer
in
Advanced Electronic Materials
volume
9
issue
12
article number
2300439
publisher
Wiley-Blackwell
external identifiers
  • scopus:85171582938
ISSN
2199-160X
DOI
10.1002/aelm.202300439
language
English
LU publication?
yes
id
0c925b1a-0080-4337-abeb-fdcdf3ffeb1b
date added to LUP
2023-12-20 13:51:12
date last changed
2023-12-20 13:52:34
@article{0c925b1a-0080-4337-abeb-fdcdf3ffeb1b,
  abstract     = {{<p>Understanding high-order biexciton dynamics is important for the use of semiconductor quantum dots (QDs) in optoelectronic devices. The core–shell structure can be used to modulate biexciton dynamics by varying the shell thickness and core–shell energy band alignment. In this study, the biexciton dynamics in an unconventional case in which each QD is encapsulated by a submonolayer shell are demonstrated. The result of a transient absorption spectroscopic study shows that InP/ZnS core/shell QDs with submonolayer shell coverage exhibit a prolonged Auger lifetime. However, the QD size dependence of the Auger recombination time features two constant distinct stages instead of the typical monotonic volume scaling law in conventional QDs. It is attributed to the tradeoff between the enlarged QD size and quantum-well confinement for the Auger processes. However, the abrupt change between the two stages is due to the change in the shell coverage. This study provides a reference for the application of core–shell QDs in optoelectronic devices in which full coverage of the shell is not achieved.</p>}},
  author       = {{Meng, Jie and Zhao, Qian and Lin, Weihua and Pullerits, Tönu and Zheng, Kaibo}},
  issn         = {{2199-160X}},
  keywords     = {{auger recombination; biexciton; indium phosphide; quantum dots; submonolayer}},
  language     = {{eng}},
  number       = {{12}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Advanced Electronic Materials}},
  title        = {{Effect of Submonolayer ZnS Shell on Biexciton Dynamics of Indium Phosphide Quantum Dots}},
  url          = {{http://dx.doi.org/10.1002/aelm.202300439}},
  doi          = {{10.1002/aelm.202300439}},
  volume       = {{9}},
  year         = {{2023}},
}