Gate- versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructures
Abstract To enable the computer-aided design of vertically stacked two-dimensional (2D) van der Waals (vdW) heterostructure devices, we here introduce a non-equilibrium first-principles simulation method based on the multi-space constrained-search density functional formalism. Applying it to graphen...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2022-03-01
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| Series: | npj Computational Materials |
| Online Access: | https://doi.org/10.1038/s41524-022-00731-9 |
| _version_ | 1811332145619140608 |
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| author | Tae Hyung Kim Juho Lee Ryong-Gyu Lee Yong-Hoon Kim |
| author_facet | Tae Hyung Kim Juho Lee Ryong-Gyu Lee Yong-Hoon Kim |
| author_sort | Tae Hyung Kim |
| collection | DOAJ |
| description | Abstract To enable the computer-aided design of vertically stacked two-dimensional (2D) van der Waals (vdW) heterostructure devices, we here introduce a non-equilibrium first-principles simulation method based on the multi-space constrained-search density functional formalism. Applying it to graphene/few-layer hBN/graphene field-effect transistors, we show that the negative differential resistance (NDR) characteristics can be produced not only from the gating-induced mismatch between two graphene Dirac cones in energy-momentum space but from the bias-dependent energetic shift of defect levels. Specifically, for a carbon atom substituted for a nitrogen atom (CN) within inner hBN layers, the increase of bias voltage is found to induce a self-consistent electron filling of in-gap CN states, which in turn changes voltage drop profiles and produces symmetric NDR characteristics. With the CN placed on outer hBN layers, however, the pinning of CN states to nearby graphene significantly modifies device characteristics, demonstrating the critical impact of atomic details for 2D vdW devices. |
| first_indexed | 2024-04-13T16:32:20Z |
| format | Article |
| id | doaj.art-570f1e6c9877439781781c716d27b48c |
| institution | Directory Open Access Journal |
| issn | 2057-3960 |
| language | English |
| last_indexed | 2024-04-13T16:32:20Z |
| publishDate | 2022-03-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj Computational Materials |
| spelling | doaj.art-570f1e6c9877439781781c716d27b48c2022-12-22T02:39:32ZengNature Portfolionpj Computational Materials2057-39602022-03-01811910.1038/s41524-022-00731-9Gate- versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructuresTae Hyung Kim0Juho Lee1Ryong-Gyu Lee2Yong-Hoon Kim3School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST)School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST)School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST)School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST)Abstract To enable the computer-aided design of vertically stacked two-dimensional (2D) van der Waals (vdW) heterostructure devices, we here introduce a non-equilibrium first-principles simulation method based on the multi-space constrained-search density functional formalism. Applying it to graphene/few-layer hBN/graphene field-effect transistors, we show that the negative differential resistance (NDR) characteristics can be produced not only from the gating-induced mismatch between two graphene Dirac cones in energy-momentum space but from the bias-dependent energetic shift of defect levels. Specifically, for a carbon atom substituted for a nitrogen atom (CN) within inner hBN layers, the increase of bias voltage is found to induce a self-consistent electron filling of in-gap CN states, which in turn changes voltage drop profiles and produces symmetric NDR characteristics. With the CN placed on outer hBN layers, however, the pinning of CN states to nearby graphene significantly modifies device characteristics, demonstrating the critical impact of atomic details for 2D vdW devices.https://doi.org/10.1038/s41524-022-00731-9 |
| spellingShingle | Tae Hyung Kim Juho Lee Ryong-Gyu Lee Yong-Hoon Kim Gate- versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructures npj Computational Materials |
| title | Gate- versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructures |
| title_full | Gate- versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructures |
| title_fullStr | Gate- versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructures |
| title_full_unstemmed | Gate- versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructures |
| title_short | Gate- versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructures |
| title_sort | gate versus defect induced voltage drop and negative differential resistance in vertical graphene heterostructures |
| url | https://doi.org/10.1038/s41524-022-00731-9 |
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