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Carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules
Carrier multiplication describes an interesting optical phenomenon in semiconductors whereby more than one electron-hole pair, or exciton, can be simultaneously generated upon absorption of a single high-energy photon. So far, it has been highly debated whether the carrier multiplication efficiency...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Pub. Group
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3493642/ https://www.ncbi.nlm.nih.gov/pubmed/23132020 http://dx.doi.org/10.1038/ncomms2183 |
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author | Xiao, Jun Wang, Ying Hua, Zheng Wang, Xiaoyong Zhang, Chunfeng Xiao, Min |
author_facet | Xiao, Jun Wang, Ying Hua, Zheng Wang, Xiaoyong Zhang, Chunfeng Xiao, Min |
author_sort | Xiao, Jun |
collection | PubMed |
description | Carrier multiplication describes an interesting optical phenomenon in semiconductors whereby more than one electron-hole pair, or exciton, can be simultaneously generated upon absorption of a single high-energy photon. So far, it has been highly debated whether the carrier multiplication efficiency is enhanced in semiconductor nanocrystals as compared with their bulk counterpart. The controversy arises from the fact that the ultrafast optical methods currently used need to correctly account for the false contribution of charged excitons to the carrier multiplication signals. Here we show that this charged exciton issue can be resolved in an energy transfer system, where biexcitons generated in the donor nanocrystals are transferred to the acceptor dyes, leading to an enhanced fluorescence from the latter. With the biexciton Auger and energy transfer lifetime measurements, an average carrier multiplication efficiency of ~17.1% can be roughly estimated in CdSe nanocrystals when the excitation photon energy is ~2.46 times of their energy gap. |
format | Online Article Text |
id | pubmed-3493642 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | Nature Pub. Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-34936422012-11-09 Carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules Xiao, Jun Wang, Ying Hua, Zheng Wang, Xiaoyong Zhang, Chunfeng Xiao, Min Nat Commun Article Carrier multiplication describes an interesting optical phenomenon in semiconductors whereby more than one electron-hole pair, or exciton, can be simultaneously generated upon absorption of a single high-energy photon. So far, it has been highly debated whether the carrier multiplication efficiency is enhanced in semiconductor nanocrystals as compared with their bulk counterpart. The controversy arises from the fact that the ultrafast optical methods currently used need to correctly account for the false contribution of charged excitons to the carrier multiplication signals. Here we show that this charged exciton issue can be resolved in an energy transfer system, where biexcitons generated in the donor nanocrystals are transferred to the acceptor dyes, leading to an enhanced fluorescence from the latter. With the biexciton Auger and energy transfer lifetime measurements, an average carrier multiplication efficiency of ~17.1% can be roughly estimated in CdSe nanocrystals when the excitation photon energy is ~2.46 times of their energy gap. Nature Pub. Group 2012-11-06 /pmc/articles/PMC3493642/ /pubmed/23132020 http://dx.doi.org/10.1038/ncomms2183 Text en Copyright © 2012, Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. http://creativecommons.org/licenses/by-nc-sa/3.0/ This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ |
spellingShingle | Article Xiao, Jun Wang, Ying Hua, Zheng Wang, Xiaoyong Zhang, Chunfeng Xiao, Min Carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules |
title | Carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules |
title_full | Carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules |
title_fullStr | Carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules |
title_full_unstemmed | Carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules |
title_short | Carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules |
title_sort | carrier multiplication in semiconductor nanocrystals detected by energy transfer to organic dye molecules |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3493642/ https://www.ncbi.nlm.nih.gov/pubmed/23132020 http://dx.doi.org/10.1038/ncomms2183 |
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