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Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons

Point defects in semiconductors can trap free charge carriers and localize excitons. The interaction between these defects and charge carriers becomes stronger at reduced dimensionalities, and is expected to greatly influence physical properties of the hosting material. We investigated effects of an...

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Autores principales: Tongay, Sefaattin, Suh, Joonki, Ataca, Can, Fan, Wen, Luce, Alexander, Kang, Jeong Seuk, Liu, Jonathan, Ko, Changhyun, Raghunathanan, Rajamani, Zhou, Jian, Ogletree, Frank, Li, Jingbo, Grossman, Jeffrey C., Wu, Junqiao
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3772378/
https://www.ncbi.nlm.nih.gov/pubmed/24029823
http://dx.doi.org/10.1038/srep02657
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author Tongay, Sefaattin
Suh, Joonki
Ataca, Can
Fan, Wen
Luce, Alexander
Kang, Jeong Seuk
Liu, Jonathan
Ko, Changhyun
Raghunathanan, Rajamani
Zhou, Jian
Ogletree, Frank
Li, Jingbo
Grossman, Jeffrey C.
Wu, Junqiao
author_facet Tongay, Sefaattin
Suh, Joonki
Ataca, Can
Fan, Wen
Luce, Alexander
Kang, Jeong Seuk
Liu, Jonathan
Ko, Changhyun
Raghunathanan, Rajamani
Zhou, Jian
Ogletree, Frank
Li, Jingbo
Grossman, Jeffrey C.
Wu, Junqiao
author_sort Tongay, Sefaattin
collection PubMed
description Point defects in semiconductors can trap free charge carriers and localize excitons. The interaction between these defects and charge carriers becomes stronger at reduced dimensionalities, and is expected to greatly influence physical properties of the hosting material. We investigated effects of anion vacancies in monolayer transition metal dichalcogenides as two-dimensional (2D) semiconductors where the vacancies density is controlled by α-particle irradiation or thermal-annealing. We found a new, sub-bandgap emission peak as well as increase in overall photoluminescence intensity as a result of the vacancy generation. Interestingly, these effects are absent when measured in vacuum. We conclude that in opposite to conventional wisdom, optical quality at room temperature cannot be used as criteria to assess crystal quality of the 2D semiconductors. Our results not only shed light on defect and exciton physics of 2D semiconductors, but also offer a new route toward tailoring optical properties of 2D semiconductors by defect engineering.
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spelling pubmed-37723782013-09-13 Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons Tongay, Sefaattin Suh, Joonki Ataca, Can Fan, Wen Luce, Alexander Kang, Jeong Seuk Liu, Jonathan Ko, Changhyun Raghunathanan, Rajamani Zhou, Jian Ogletree, Frank Li, Jingbo Grossman, Jeffrey C. Wu, Junqiao Sci Rep Article Point defects in semiconductors can trap free charge carriers and localize excitons. The interaction between these defects and charge carriers becomes stronger at reduced dimensionalities, and is expected to greatly influence physical properties of the hosting material. We investigated effects of anion vacancies in monolayer transition metal dichalcogenides as two-dimensional (2D) semiconductors where the vacancies density is controlled by α-particle irradiation or thermal-annealing. We found a new, sub-bandgap emission peak as well as increase in overall photoluminescence intensity as a result of the vacancy generation. Interestingly, these effects are absent when measured in vacuum. We conclude that in opposite to conventional wisdom, optical quality at room temperature cannot be used as criteria to assess crystal quality of the 2D semiconductors. Our results not only shed light on defect and exciton physics of 2D semiconductors, but also offer a new route toward tailoring optical properties of 2D semiconductors by defect engineering. Nature Publishing Group 2013-09-13 /pmc/articles/PMC3772378/ /pubmed/24029823 http://dx.doi.org/10.1038/srep02657 Text en Copyright © 2013, Macmillan Publishers Limited. All rights reserved http://creativecommons.org/licenses/by/3.0/ This work is licensed under a Creative Commons Attribution 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/
spellingShingle Article
Tongay, Sefaattin
Suh, Joonki
Ataca, Can
Fan, Wen
Luce, Alexander
Kang, Jeong Seuk
Liu, Jonathan
Ko, Changhyun
Raghunathanan, Rajamani
Zhou, Jian
Ogletree, Frank
Li, Jingbo
Grossman, Jeffrey C.
Wu, Junqiao
Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons
title Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons
title_full Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons
title_fullStr Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons
title_full_unstemmed Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons
title_short Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons
title_sort defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3772378/
https://www.ncbi.nlm.nih.gov/pubmed/24029823
http://dx.doi.org/10.1038/srep02657
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