Interface engineering of charge-transfer excitons in 2D lateral heterostructures
Abstract The existence of bound charge transfer (CT) excitons at the interface of monolayer lateral heterojunctions has been debated in literature, but contrary to the case of interlayer excitons in vertical heterostructure their observation still has to be confirmed. Here, we present a microscopic...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-04-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-023-37889-9 |
| _version_ | 1827956713037234176 |
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| author | Roberto Rosati Ioannis Paradisanos Libai Huang Ziyang Gan Antony George Kenji Watanabe Takashi Taniguchi Laurent Lombez Pierre Renucci Andrey Turchanin Bernhard Urbaszek Ermin Malic |
| author_facet | Roberto Rosati Ioannis Paradisanos Libai Huang Ziyang Gan Antony George Kenji Watanabe Takashi Taniguchi Laurent Lombez Pierre Renucci Andrey Turchanin Bernhard Urbaszek Ermin Malic |
| author_sort | Roberto Rosati |
| collection | DOAJ |
| description | Abstract The existence of bound charge transfer (CT) excitons at the interface of monolayer lateral heterojunctions has been debated in literature, but contrary to the case of interlayer excitons in vertical heterostructure their observation still has to be confirmed. Here, we present a microscopic study investigating signatures of bound CT excitons in photoluminescence spectra at the interface of hBN-encapsulated lateral MoSe2-WSe2 heterostructures. Based on a fully microscopic and material-specific theory, we reveal the many-particle processes behind the formation of CT excitons and how they can be tuned via interface- and dielectric engineering. For junction widths smaller than the Coulomb-induced Bohr radius we predict the appearance of a low-energy CT exciton. The theoretical prediction is compared with experimental low-temperature photoluminescence measurements showing emission in the bound CT excitons energy range. We show that for hBN-encapsulated heterostructures, CT excitons exhibit small binding energies of just a few tens meV and at the same time large dipole moments, making them promising materials for optoelectronic applications (benefiting from an efficient exciton dissociation and fast dipole-driven exciton propagation). Our joint theory-experiment study presents a significant step towards a microscopic understanding of optical properties of technologically promising 2D lateral heterostructures. |
| first_indexed | 2024-04-09T15:09:08Z |
| format | Article |
| id | doaj.art-f8678d09fc7945e0b91db15e93e191de |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2024-04-09T15:09:08Z |
| publishDate | 2023-04-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-f8678d09fc7945e0b91db15e93e191de2023-04-30T11:21:57ZengNature PortfolioNature Communications2041-17232023-04-011411910.1038/s41467-023-37889-9Interface engineering of charge-transfer excitons in 2D lateral heterostructuresRoberto Rosati0Ioannis Paradisanos1Libai Huang2Ziyang Gan3Antony George4Kenji Watanabe5Takashi Taniguchi6Laurent Lombez7Pierre Renucci8Andrey Turchanin9Bernhard Urbaszek10Ermin Malic11Department of Physics, Philipps-Universität MarburgUniversité de Toulouse, INSA-CNRS-UPS, LPCNODepartment of Chemistry, Purdue UniversityFriedrich Schiller University Jena, Institute of Physical ChemistryFriedrich Schiller University Jena, Institute of Physical ChemistryResearch Center for Functional Materials, National Institute for Materials ScienceInternational Center for Materials Nanoarchitectonics, National Institute for Materials ScienceUniversité de Toulouse, INSA-CNRS-UPS, LPCNOUniversité de Toulouse, INSA-CNRS-UPS, LPCNOFriedrich Schiller University Jena, Institute of Physical ChemistryUniversité de Toulouse, INSA-CNRS-UPS, LPCNODepartment of Physics, Philipps-Universität MarburgAbstract The existence of bound charge transfer (CT) excitons at the interface of monolayer lateral heterojunctions has been debated in literature, but contrary to the case of interlayer excitons in vertical heterostructure their observation still has to be confirmed. Here, we present a microscopic study investigating signatures of bound CT excitons in photoluminescence spectra at the interface of hBN-encapsulated lateral MoSe2-WSe2 heterostructures. Based on a fully microscopic and material-specific theory, we reveal the many-particle processes behind the formation of CT excitons and how they can be tuned via interface- and dielectric engineering. For junction widths smaller than the Coulomb-induced Bohr radius we predict the appearance of a low-energy CT exciton. The theoretical prediction is compared with experimental low-temperature photoluminescence measurements showing emission in the bound CT excitons energy range. We show that for hBN-encapsulated heterostructures, CT excitons exhibit small binding energies of just a few tens meV and at the same time large dipole moments, making them promising materials for optoelectronic applications (benefiting from an efficient exciton dissociation and fast dipole-driven exciton propagation). Our joint theory-experiment study presents a significant step towards a microscopic understanding of optical properties of technologically promising 2D lateral heterostructures.https://doi.org/10.1038/s41467-023-37889-9 |
| spellingShingle | Roberto Rosati Ioannis Paradisanos Libai Huang Ziyang Gan Antony George Kenji Watanabe Takashi Taniguchi Laurent Lombez Pierre Renucci Andrey Turchanin Bernhard Urbaszek Ermin Malic Interface engineering of charge-transfer excitons in 2D lateral heterostructures Nature Communications |
| title | Interface engineering of charge-transfer excitons in 2D lateral heterostructures |
| title_full | Interface engineering of charge-transfer excitons in 2D lateral heterostructures |
| title_fullStr | Interface engineering of charge-transfer excitons in 2D lateral heterostructures |
| title_full_unstemmed | Interface engineering of charge-transfer excitons in 2D lateral heterostructures |
| title_short | Interface engineering of charge-transfer excitons in 2D lateral heterostructures |
| title_sort | interface engineering of charge transfer excitons in 2d lateral heterostructures |
| url | https://doi.org/10.1038/s41467-023-37889-9 |
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