The role of ion exchange in the passivation of In(Zn)P nanocrystals with ZnS

We have investigated the chemical state of In(Zn)P/ZnS core/shell nanocrystals (NCs) for color conversion applications using hard X-ray absorption spectroscopy (XAS) and photoluminescence excitation (PLE). Analyses of the edge energies as well as the X-ray absorption fine structure (XAFS) reveal tha...

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Main Authors: Cho, Deok-Yong, Xi, Lifei, Boothroyd, Chris, Kardynal, Beata, Lam, Yeng Ming
Other Authors: School of Materials Science & Engineering
Format: Article
Language:English
Published: 2018
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Online Access:https://hdl.handle.net/10356/87613
http://hdl.handle.net/10220/46760
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Institution: Nanyang Technological University
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spelling sg-ntu-dr.10356-876132023-07-14T15:51:58Z The role of ion exchange in the passivation of In(Zn)P nanocrystals with ZnS Cho, Deok-Yong Xi, Lifei Boothroyd, Chris Kardynal, Beata Lam, Yeng Ming School of Materials Science & Engineering Nanocrystals Ion Exchange DRNTU::Engineering::Materials We have investigated the chemical state of In(Zn)P/ZnS core/shell nanocrystals (NCs) for color conversion applications using hard X-ray absorption spectroscopy (XAS) and photoluminescence excitation (PLE). Analyses of the edge energies as well as the X-ray absorption fine structure (XAFS) reveal that the Zn2+ ions from ZnS remain in the shell while the S2− ions penetrate into the core at an early stage of the ZnS deposition. It is further demonstrated that for short growth times, the ZnS shell coverage on the core was incomplete, whereas the coverage improved gradually as the shell deposition time increased. Together with evidence from PLE spectra, where there is a strong indication of the presence of P vacancies, this suggests that the core-shell interface in the In(Zn)P/ZnS NCs are subject to substantial atomic exchanges and detailed models for the shell structure beyond simple layer coverage are needed. This substantial atomic exchange is very likely to be the reason for the improved photoluminescence behavior of the core-shell particles compare to In(Zn)P-only NCs as S can passivate the NCs surfaces. MOE (Min. of Education, S’pore) Published version 2018-12-03T01:38:27Z 2019-12-06T16:45:40Z 2018-12-03T01:38:27Z 2019-12-06T16:45:40Z 2016 Journal Article Cho, D.-Y., Xi, L., Boothroyd, C., Kardynal, B., & Lam, Y. M. (2016). The role of ion exchange in the passivation of In(Zn)P nanocrystals with ZnS. Scientific Reports, 6, 22818-. doi:10.1038/srep22818 https://hdl.handle.net/10356/87613 http://hdl.handle.net/10220/46760 10.1038/srep22818 26972936 en Scientific Reports © 2016 The Authors (Nature Publishing Group). This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ 8 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Nanocrystals
Ion Exchange
DRNTU::Engineering::Materials
spellingShingle Nanocrystals
Ion Exchange
DRNTU::Engineering::Materials
Cho, Deok-Yong
Xi, Lifei
Boothroyd, Chris
Kardynal, Beata
Lam, Yeng Ming
The role of ion exchange in the passivation of In(Zn)P nanocrystals with ZnS
description We have investigated the chemical state of In(Zn)P/ZnS core/shell nanocrystals (NCs) for color conversion applications using hard X-ray absorption spectroscopy (XAS) and photoluminescence excitation (PLE). Analyses of the edge energies as well as the X-ray absorption fine structure (XAFS) reveal that the Zn2+ ions from ZnS remain in the shell while the S2− ions penetrate into the core at an early stage of the ZnS deposition. It is further demonstrated that for short growth times, the ZnS shell coverage on the core was incomplete, whereas the coverage improved gradually as the shell deposition time increased. Together with evidence from PLE spectra, where there is a strong indication of the presence of P vacancies, this suggests that the core-shell interface in the In(Zn)P/ZnS NCs are subject to substantial atomic exchanges and detailed models for the shell structure beyond simple layer coverage are needed. This substantial atomic exchange is very likely to be the reason for the improved photoluminescence behavior of the core-shell particles compare to In(Zn)P-only NCs as S can passivate the NCs surfaces.
author2 School of Materials Science & Engineering
author_facet School of Materials Science & Engineering
Cho, Deok-Yong
Xi, Lifei
Boothroyd, Chris
Kardynal, Beata
Lam, Yeng Ming
format Article
author Cho, Deok-Yong
Xi, Lifei
Boothroyd, Chris
Kardynal, Beata
Lam, Yeng Ming
author_sort Cho, Deok-Yong
title The role of ion exchange in the passivation of In(Zn)P nanocrystals with ZnS
title_short The role of ion exchange in the passivation of In(Zn)P nanocrystals with ZnS
title_full The role of ion exchange in the passivation of In(Zn)P nanocrystals with ZnS
title_fullStr The role of ion exchange in the passivation of In(Zn)P nanocrystals with ZnS
title_full_unstemmed The role of ion exchange in the passivation of In(Zn)P nanocrystals with ZnS
title_sort role of ion exchange in the passivation of in(zn)p nanocrystals with zns
publishDate 2018
url https://hdl.handle.net/10356/87613
http://hdl.handle.net/10220/46760
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