Direct observation of ferroelectricity in two-dimensional MoS2
Abstract Recent theoretical predictions of ferroelectricity in two-dimensional (2D) van der Waals materials reveal exciting possibilities for their use in scalable low-power electronic devices with polarization-dependent functionalities. These prospects have been further invigorated by the experimen...
| 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 2D Materials and Applications |
| Online Access: | https://doi.org/10.1038/s41699-022-00298-5 |
| _version_ | 1818315484932603904 |
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| author | Alexey Lipatov Pradeep Chaudhary Zhao Guan Haidong Lu Gang Li Olivier Crégut Kokou Dodzi Dorkenoo Roger Proksch Salia Cherifi-Hertel Ding-Fu Shao Evgeny Y. Tsymbal Jorge Íñiguez Alexander Sinitskii Alexei Gruverman |
| author_facet | Alexey Lipatov Pradeep Chaudhary Zhao Guan Haidong Lu Gang Li Olivier Crégut Kokou Dodzi Dorkenoo Roger Proksch Salia Cherifi-Hertel Ding-Fu Shao Evgeny Y. Tsymbal Jorge Íñiguez Alexander Sinitskii Alexei Gruverman |
| author_sort | Alexey Lipatov |
| collection | DOAJ |
| description | Abstract Recent theoretical predictions of ferroelectricity in two-dimensional (2D) van der Waals materials reveal exciting possibilities for their use in scalable low-power electronic devices with polarization-dependent functionalities. These prospects have been further invigorated by the experimental evidence of the polarization response in some transition metal chalcogenides (TMCs)—a group of narrow-band semiconductors and semimetals with a wealth of application potential. Among the TMCs, molybdenum disulfide (MoS2) is known as one of the most promising and robust 2D electronic materials. However, in spite of theoretical predictions, no ferroelectricity has been experimentally detected in MoS2, while the emergence of this property could enhance its potential for electronics applications. Here, we report the experimental observation of a stable room-temperature out-of-plane polarization ordering in 2D MoS2 layers, where polarization switching is realized by mechanical pressure induced by a tip of a scanning probe microscope. Using this approach, we create the bi-domain polarization states, which exhibit different piezoelectric activity, second harmonic generation, surface potential, and conductivity. Ferroelectric MoS2 belongs to the distorted trigonal structural 1T” phase, where a spontaneous polarization is inferred by its P3m1 space-group symmetry and corroborated by theoretical modeling. Experiments on the flipped flakes reveal that the 1T”-MoS2 samples consist of the monolayers with randomly alternating polarization orientation, which form stable but switchable “antipolar” head-to-head or tail-to-tail dipole configurations. Mechanically written domains are remarkably stable facilitating the application of 1T”-MoS2 in flexible memory and electromechanical devices. |
| first_indexed | 2024-12-13T09:06:17Z |
| format | Article |
| id | doaj.art-d8b91459ff8141318fc94f6e40258342 |
| institution | Directory Open Access Journal |
| issn | 2397-7132 |
| language | English |
| last_indexed | 2024-12-13T09:06:17Z |
| publishDate | 2022-03-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj 2D Materials and Applications |
| spelling | doaj.art-d8b91459ff8141318fc94f6e402583422022-12-21T23:53:03ZengNature Portfolionpj 2D Materials and Applications2397-71322022-03-01611910.1038/s41699-022-00298-5Direct observation of ferroelectricity in two-dimensional MoS2Alexey Lipatov0Pradeep Chaudhary1Zhao Guan2Haidong Lu3Gang Li4Olivier Crégut5Kokou Dodzi Dorkenoo6Roger Proksch7Salia Cherifi-Hertel8Ding-Fu Shao9Evgeny Y. Tsymbal10Jorge Íñiguez11Alexander Sinitskii12Alexei Gruverman13Department of Chemistry, University of NebraskaDepartment of Physics and Astronomy, University of NebraskaKey Laboratory of Polar Materials and Devices and Department of Electronics, East China Normal UniversityDepartment of Physics and Astronomy, University of NebraskaDepartment of Chemistry, University of NebraskaUniversité de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504Asylum Research, an Oxford Instruments CompanyUniversité de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504Department of Physics and Astronomy, University of NebraskaDepartment of Physics and Astronomy, University of NebraskaDepartment of Physics and Materials Science, University of LuxembourgDepartment of Chemistry, University of NebraskaDepartment of Physics and Astronomy, University of NebraskaAbstract Recent theoretical predictions of ferroelectricity in two-dimensional (2D) van der Waals materials reveal exciting possibilities for their use in scalable low-power electronic devices with polarization-dependent functionalities. These prospects have been further invigorated by the experimental evidence of the polarization response in some transition metal chalcogenides (TMCs)—a group of narrow-band semiconductors and semimetals with a wealth of application potential. Among the TMCs, molybdenum disulfide (MoS2) is known as one of the most promising and robust 2D electronic materials. However, in spite of theoretical predictions, no ferroelectricity has been experimentally detected in MoS2, while the emergence of this property could enhance its potential for electronics applications. Here, we report the experimental observation of a stable room-temperature out-of-plane polarization ordering in 2D MoS2 layers, where polarization switching is realized by mechanical pressure induced by a tip of a scanning probe microscope. Using this approach, we create the bi-domain polarization states, which exhibit different piezoelectric activity, second harmonic generation, surface potential, and conductivity. Ferroelectric MoS2 belongs to the distorted trigonal structural 1T” phase, where a spontaneous polarization is inferred by its P3m1 space-group symmetry and corroborated by theoretical modeling. Experiments on the flipped flakes reveal that the 1T”-MoS2 samples consist of the monolayers with randomly alternating polarization orientation, which form stable but switchable “antipolar” head-to-head or tail-to-tail dipole configurations. Mechanically written domains are remarkably stable facilitating the application of 1T”-MoS2 in flexible memory and electromechanical devices.https://doi.org/10.1038/s41699-022-00298-5 |
| spellingShingle | Alexey Lipatov Pradeep Chaudhary Zhao Guan Haidong Lu Gang Li Olivier Crégut Kokou Dodzi Dorkenoo Roger Proksch Salia Cherifi-Hertel Ding-Fu Shao Evgeny Y. Tsymbal Jorge Íñiguez Alexander Sinitskii Alexei Gruverman Direct observation of ferroelectricity in two-dimensional MoS2 npj 2D Materials and Applications |
| title | Direct observation of ferroelectricity in two-dimensional MoS2 |
| title_full | Direct observation of ferroelectricity in two-dimensional MoS2 |
| title_fullStr | Direct observation of ferroelectricity in two-dimensional MoS2 |
| title_full_unstemmed | Direct observation of ferroelectricity in two-dimensional MoS2 |
| title_short | Direct observation of ferroelectricity in two-dimensional MoS2 |
| title_sort | direct observation of ferroelectricity in two dimensional mos2 |
| url | https://doi.org/10.1038/s41699-022-00298-5 |
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