Layer-dependent Schottky contact at van der Waals interfaces: V-doped WSe2 on graphene
Abstract Contacting two-dimensional (2D) semiconductors with van der Waals semimetals significantly reduces the contact resistance and Fermi level pinning due to defect-free interfaces. However, depending on the band alignment, a Schottky barrier remains. Here we study the evolution of the valence a...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2022-09-01
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| Series: | npj 2D Materials and Applications |
| Online Access: | https://doi.org/10.1038/s41699-022-00342-4 |
| _version_ | 1811267442493620224 |
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| author | Samuel Stolz Azimkhan Kozhakhmetov Chengye Dong Oliver Gröning Joshua A. Robinson Bruno Schuler |
| author_facet | Samuel Stolz Azimkhan Kozhakhmetov Chengye Dong Oliver Gröning Joshua A. Robinson Bruno Schuler |
| author_sort | Samuel Stolz |
| collection | DOAJ |
| description | Abstract Contacting two-dimensional (2D) semiconductors with van der Waals semimetals significantly reduces the contact resistance and Fermi level pinning due to defect-free interfaces. However, depending on the band alignment, a Schottky barrier remains. Here we study the evolution of the valence and conduction band edges in pristine and heavily vanadium (0.44%), i.e., p-type, doped epitaxial WSe2 on quasi-freestanding graphene (QFEG) on silicon carbide as a function of thickness. We find that with increasing number of layers the Fermi level of the doped WSe2 gets pinned at the highest dopant level for three or more monolayers. This implies a charge depletion region of about 1.6 nm. Consequently, V dopants in the first and second WSe2 layer on QFEG/SiC are ionized (negatively charged) whereas they are charge neutral beyond the second layer. |
| first_indexed | 2024-04-12T21:02:41Z |
| format | Article |
| id | doaj.art-7fe843a0c00c485786ac4ac04821ed3e |
| institution | Directory Open Access Journal |
| issn | 2397-7132 |
| language | English |
| last_indexed | 2024-04-12T21:02:41Z |
| publishDate | 2022-09-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj 2D Materials and Applications |
| spelling | doaj.art-7fe843a0c00c485786ac4ac04821ed3e2022-12-22T03:16:48ZengNature Portfolionpj 2D Materials and Applications2397-71322022-09-01611510.1038/s41699-022-00342-4Layer-dependent Schottky contact at van der Waals interfaces: V-doped WSe2 on grapheneSamuel Stolz0Azimkhan Kozhakhmetov1Chengye Dong2Oliver Gröning3Joshua A. Robinson4Bruno Schuler5nanotech@surfaces Laboratory, Empa—Swiss Federal Laboratories for Materials Science and TechnologyDepartment of Materials Science and Engineering, The Pennsylvania State UniversityTwo-Dimensional Crystal Consortium, The Pennsylvania State Universitynanotech@surfaces Laboratory, Empa—Swiss Federal Laboratories for Materials Science and TechnologyDepartment of Materials Science and Engineering, The Pennsylvania State Universitynanotech@surfaces Laboratory, Empa—Swiss Federal Laboratories for Materials Science and TechnologyAbstract Contacting two-dimensional (2D) semiconductors with van der Waals semimetals significantly reduces the contact resistance and Fermi level pinning due to defect-free interfaces. However, depending on the band alignment, a Schottky barrier remains. Here we study the evolution of the valence and conduction band edges in pristine and heavily vanadium (0.44%), i.e., p-type, doped epitaxial WSe2 on quasi-freestanding graphene (QFEG) on silicon carbide as a function of thickness. We find that with increasing number of layers the Fermi level of the doped WSe2 gets pinned at the highest dopant level for three or more monolayers. This implies a charge depletion region of about 1.6 nm. Consequently, V dopants in the first and second WSe2 layer on QFEG/SiC are ionized (negatively charged) whereas they are charge neutral beyond the second layer.https://doi.org/10.1038/s41699-022-00342-4 |
| spellingShingle | Samuel Stolz Azimkhan Kozhakhmetov Chengye Dong Oliver Gröning Joshua A. Robinson Bruno Schuler Layer-dependent Schottky contact at van der Waals interfaces: V-doped WSe2 on graphene npj 2D Materials and Applications |
| title | Layer-dependent Schottky contact at van der Waals interfaces: V-doped WSe2 on graphene |
| title_full | Layer-dependent Schottky contact at van der Waals interfaces: V-doped WSe2 on graphene |
| title_fullStr | Layer-dependent Schottky contact at van der Waals interfaces: V-doped WSe2 on graphene |
| title_full_unstemmed | Layer-dependent Schottky contact at van der Waals interfaces: V-doped WSe2 on graphene |
| title_short | Layer-dependent Schottky contact at van der Waals interfaces: V-doped WSe2 on graphene |
| title_sort | layer dependent schottky contact at van der waals interfaces v doped wse2 on graphene |
| url | https://doi.org/10.1038/s41699-022-00342-4 |
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