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Van Winkle M, Dowlatshahi N, Khaloo N, Iyer M, Craig IM, Dhall R, Taniguchi T, Watanabe K, Bediako DK. Engineering interfacial polarization switching in van der Waals multilayers. Nat Nanotechnol 2024:10.1038/s41565-024-01642-0. [PMID: 38504024 DOI: 10.1038/s41565-024-01642-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 02/29/2024] [Indexed: 03/21/2024]
Abstract
In conventional ferroelectric materials, polarization is an intrinsic property limited by bulk crystallographic structure and symmetry. Recently, it has been demonstrated that polar order can also be accessed using inherently non-polar van der Waals materials through layer-by-layer assembly into heterostructures, wherein interfacial interactions can generate spontaneous, switchable polarization. Here we show that deliberate interlayer rotations in multilayer van der Waals heterostructures modulate both the spatial ordering and switching dynamics of polar domains. The engendered tunability is unparalleled in conventional bulk ferroelectrics or polar bilayers. By means of operando transmission electron microscopy we show how alterations of the relative rotations of three WSe2 layers produce structural polytypes with distinct arrangements of polar domains with either a global or localized switching response. Furthermore, the presence of uniaxial strain generates structural anisotropy that yields a range of switching behaviours, coercivities and even tunable biased responses. We also provide evidence of mechanical coupling between the two interfaces of the trilayer, a key consideration for the control of switching dynamics in polar multilayer structures more broadly.
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Affiliation(s)
- Madeline Van Winkle
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Nikita Dowlatshahi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Nikta Khaloo
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Mrinalni Iyer
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
- Department of Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Isaac M Craig
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Rohan Dhall
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, Tsukuba, Japan
| | - D Kwabena Bediako
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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Zhang K, Yu Y, Carr S, Babar M, Zhu Z, Kim BJ, Groschner C, Khaloo N, Taniguchi T, Watanabe K, Viswanathan V, Bediako DK. Anomalous Interfacial Electron-Transfer Kinetics in Twisted Trilayer Graphene Caused by Layer-Specific Localization. ACS Cent Sci 2023; 9:1119-1128. [PMID: 37396866 PMCID: PMC10311658 DOI: 10.1021/acscentsci.3c00326] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Indexed: 07/04/2023]
Abstract
Interfacial electron-transfer (ET) reactions underpin the interconversion of electrical and chemical energy. It is known that the electronic state of electrodes strongly influences ET rates because of differences in the electronic density of states (DOS) across metals, semimetals, and semiconductors. Here, by controlling interlayer twists in well-defined trilayer graphene moirés, we show that ET rates are strikingly dependent on electronic localization in each atomic layer and not the overall DOS. The large degree of tunability inherent to moiré electrodes leads to local ET kinetics that range over 3 orders of magnitude across different constructions of only three atomic layers, even exceeding rates at bulk metals. Our results demonstrate that beyond the ensemble DOS, electronic localization is critical in facilitating interfacial ET, with implications for understanding the origin of high interfacial reactivity typically exhibited by defects at electrode-electrolyte interfaces.
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Affiliation(s)
- Kaidi Zhang
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Yun Yu
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Stephen Carr
- Brown
Theoretical Physics Center, Brown University, Providence, Rhode Island 02912, United States
| | - Mohammad Babar
- Department
of Mechanical Engineering, Carnegie Mellon
University, Pittsburgh, Pennsylvania 15213, United States
| | - Ziyan Zhu
- SLAC
National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Bryan Junsuh Kim
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Catherine Groschner
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Nikta Khaloo
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Takashi Taniguchi
- International
Center for Materials Nanoarchitectonics, National Institute for Materials Science, 305-0044 Tsukuba, Japan
| | - Kenji Watanabe
- Research
Center for Functional Materials, National
Institute for Materials Science, 305-0044 Tsukuba, Japan
| | | | - D. Kwabena Bediako
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
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