An anomalous interlayer exciton in MoS2
The few layer transition metal dichalcogenides are two dimensional materials that have an intrinsic gap of the order of ≈2 eV. The reduced screening in two dimensions implies a rich excitonic physics and, as a consequence, many potential applications in the field of opto-electronics. Here we report...
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Nature Publishing Group
2016
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5107944/ |
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pubmed-51079442016-11-22 An anomalous interlayer exciton in MoS2 Azhikodan, Dilna Nautiyal, Tashi Shallcross, Sam Sharma, Sangeeta Article The few layer transition metal dichalcogenides are two dimensional materials that have an intrinsic gap of the order of ≈2 eV. The reduced screening in two dimensions implies a rich excitonic physics and, as a consequence, many potential applications in the field of opto-electronics. Here we report that a layer perpendicular electric field, by which the gap size in these materials can be efficiently controlled, generates an anomalous inter-layer exciton whose binding energy is independent of the gap size. We show this originates from the rich gap control and screening physics of TMDCs in a bilayer geometry: gating the bilayer acts on one hand to increase intra-layer screening by reducing the gap and, on the other hand, to decrease the inter-layer screening by field induced charge depletion. This constancy of binding energy is both a striking exception to the universal reduction in binding energy with gap size that all materials are believed to follow, as well as evidence of a degree of control over inter-layer excitons not found in their well studied intra-layer counterparts. Nature Publishing Group 2016-11-14 /pmc/articles/PMC5107944/ /pubmed/27841337 http://dx.doi.org/10.1038/srep37075 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ 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/ |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Azhikodan, Dilna Nautiyal, Tashi Shallcross, Sam Sharma, Sangeeta |
| spellingShingle |
Azhikodan, Dilna Nautiyal, Tashi Shallcross, Sam Sharma, Sangeeta An anomalous interlayer exciton in MoS2 |
| author_facet |
Azhikodan, Dilna Nautiyal, Tashi Shallcross, Sam Sharma, Sangeeta |
| author_sort |
Azhikodan, Dilna |
| title |
An anomalous interlayer exciton in MoS2 |
| title_short |
An anomalous interlayer exciton in MoS2 |
| title_full |
An anomalous interlayer exciton in MoS2 |
| title_fullStr |
An anomalous interlayer exciton in MoS2 |
| title_full_unstemmed |
An anomalous interlayer exciton in MoS2 |
| title_sort |
anomalous interlayer exciton in mos2 |
| description |
The few layer transition metal dichalcogenides are two dimensional materials that have an intrinsic gap of the order of ≈2 eV. The reduced screening in two dimensions implies a rich excitonic physics and, as a consequence, many potential applications in the field of opto-electronics. Here we report that a layer perpendicular electric field, by which the gap size in these materials can be efficiently controlled, generates an anomalous inter-layer exciton whose binding energy is independent of the gap size. We show this originates from the rich gap control and screening physics of TMDCs in a bilayer geometry: gating the bilayer acts on one hand to increase intra-layer screening by reducing the gap and, on the other hand, to decrease the inter-layer screening by field induced charge depletion. This constancy of binding energy is both a striking exception to the universal reduction in binding energy with gap size that all materials are believed to follow, as well as evidence of a degree of control over inter-layer excitons not found in their well studied intra-layer counterparts. |
| publisher |
Nature Publishing Group |
| publishDate |
2016 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5107944/ |
| _version_ |
1613725619974045696 |