1
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Li N, Jabegu T, He R, Yun S, Ghosh S, Maraba D, Olunloyo O, Ma H, Okmi A, Xiao K, Wang G, Dong P, Lei S. Covalently-Bonded Laminar Assembly of Van der Waals Semiconductors with Polymers: Toward High-Performance Flexible Devices. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2310175. [PMID: 38402424 DOI: 10.1002/smll.202310175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 02/02/2024] [Indexed: 02/26/2024]
Abstract
Van der Waals semiconductors (vdWS) offer superior mechanical and electrical properties and are promising for flexible microelectronics when combined with polymer substrates. However, the self-passivated vdWS surfaces and their weak adhesion to polymers tend to cause interfacial sliding and wrinkling, and thus, are still challenging the reliability of vdWS-based flexible devices. Here, an effective covalent vdWS-polymer lamination method with high stretch tolerance and excellent electronic performance is reported. Using molybdenum disulfide (MoS2 )and polydimethylsiloxane (PDMS) as a case study, gold-chalcogen bonding and mercapto silane bridges are leveraged. The resulting composite structures exhibit more uniform and stronger interfacial adhesion. This enhanced coupling also enables the observation of a theoretically predicted tension-induced band structure transition in MoS2 . Moreover, no obvious degradation in the devices' structural and electrical properties is identified after numerous mechanical cycle tests. This high-quality lamination enhances the reliability of vdWS-based flexible microelectronics, accelerating their practical applications in biomedical research and consumer electronics.
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Affiliation(s)
- Ningxin Li
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
| | - Tara Jabegu
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
| | - Rui He
- Department of Mechanical Engineering, George Mason University, Fairfax, VA, 22030, USA
| | - Seokjoon Yun
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Sujoy Ghosh
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Diren Maraba
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
| | - Olugbenga Olunloyo
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Knoxville, TN, 37996, USA
| | - Hedi Ma
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
| | - Aisha Okmi
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
| | - Kai Xiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Gangli Wang
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
| | - Pei Dong
- Department of Mechanical Engineering, George Mason University, Fairfax, VA, 22030, USA
| | - Sidong Lei
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
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2
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De Palma AC, Peng X, Arash S, Gao FY, Baldini E, Li X, Yu ET. Elucidating Piezoelectricity and Strain in Monolayer MoS 2 at the Nanoscale Using Kelvin Probe Force Microscopy. NANO LETTERS 2024; 24:1835-1842. [PMID: 38315833 DOI: 10.1021/acs.nanolett.3c03100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Strain engineering modifies the optical and electronic properties of atomically thin transition metal dichalcogenides. Highly inhomogeneous strain distributions in two-dimensional materials can be easily realized, enabling control of properties on the nanoscale; however, methods for probing strain on the nanoscale remain challenging. In this work, we characterize inhomogeneously strained monolayer MoS2 via Kelvin probe force microscopy and electrostatic gating, isolating the contributions of strain from other electrostatic effects and enabling the measurement of all components of the two-dimensional strain tensor on length scales less than 100 nm. The combination of these methods is used to calculate the spatial distribution of the electrostatic potential resulting from piezoelectricity, presenting a powerful way to characterize inhomogeneous strain and piezoelectricity that can be extended toward a variety of 2D materials.
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Affiliation(s)
- Alex C De Palma
- Materials Science and Engineering Program, Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712, United States
| | - Xinyue Peng
- Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, United States
| | - Saba Arash
- Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, United States
| | - Frank Y Gao
- Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, United States
| | - Edoardo Baldini
- Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, United States
| | - Xiaoqin Li
- Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, United States
| | - Edward T Yu
- Materials Science and Engineering Program, Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712, United States
- Microelectronics Research Center, Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, Texas 78758, United States
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3
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Scott RJ, Valencia-Acuna P, Zhao H. Spatiotemporal Observation of Quasi-Ballistic Transport of Electrons in Graphene. ACS NANO 2023; 17:25368-25376. [PMID: 38091261 DOI: 10.1021/acsnano.3c08816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
We report spatiotemporal observations of room-temperature quasi-ballistic electron transport in graphene, which is achieved by utilizing a four-layer van der Waals heterostructure to generate free charge carriers. The heterostructure is formed by sandwiching a MoS2 and MoSe2 heterobilayer between two graphene monolayers. Transient absorption measurements reveal that the electrons and holes separated by the type-II interface between MoS2 and MoSe2 can transfer to the two graphene layers, respectively. Transient absorption microscopy measurements, with high spatial and temporal resolution, reveal that while the holes in one graphene layer undergo a classical diffusion process with a large diffusion coefficient of 65 cm2 s-1 and a charge mobility of 5000 cm2 V-1 s-1, the electrons in the other graphene layer exhibit a quasi-ballistic transport feature, with a ballistic transport time of 20 ps and a speed of 22 km s-1, respectively. The different in-plane transport properties confirm that electrons and holes move independently of each other as charge carriers. The optical generation of ballistic charge carriers suggests potential applications for such van der Waals heterostructures as optoelectronic materials.
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Affiliation(s)
- Ryan J Scott
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Pavel Valencia-Acuna
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Hui Zhao
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
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4
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Baek JH, Kim HG, Lim SY, Hong SC, Chang Y, Ryu H, Jung Y, Jang H, Kim J, Zhang Y, Watanabe K, Taniguchi T, Huang PY, Cheong H, Kim M, Lee GH. Thermally induced atomic reconstruction into fully commensurate structures of transition metal dichalcogenide layers. NATURE MATERIALS 2023:10.1038/s41563-023-01690-2. [PMID: 37828101 DOI: 10.1038/s41563-023-01690-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 09/13/2023] [Indexed: 10/14/2023]
Abstract
Twist angle between two-dimensional layers is a critical parameter that determines their interfacial properties, such as moiré excitons and interfacial ferro-electricity. To achieve better control over these properties for fundamental studies and various applications, considerable efforts have been made to manipulate twist angle. However, due to mechanical limitations and the inevitable formation of incommensurate regions, there remains a challenge in attaining perfect alignment of crystalline orientation. Here we report a thermally induced atomic reconstruction of randomly stacked transition metal dichalcogenide multilayers into fully commensurate heterostructures with zero twist angle by encapsulation annealing, regardless of twist angles of as-stacked samples and lattice mismatches. We also demonstrate the selective formation of R- and H-type fully commensurate phases with a seamless lateral junction using chemical vapour-deposited transition metal dichalcogenides. The resulting fully commensurate phases exhibit strong photoluminescence enhancement of the interlayer excitons, even at room temperature, due to their commensurate structure with aligned momentum coordinates. Our work not only demonstrates a way to fabricate zero-twisted, two-dimensional bilayers with R- and H-type configurations, but also provides a platform for studying their unexplored properties.
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Affiliation(s)
- Ji-Hwan Baek
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Hyoung Gyun Kim
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Soo Yeon Lim
- Department of Physics, Sogang University, Seoul, Korea
| | - Seong Chul Hong
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Yunyeong Chang
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Huije Ryu
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Yeonjoon Jung
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Hajung Jang
- Department of Physics, Sogang University, Seoul, Korea
| | - Jungcheol Kim
- Department of Physics, Sogang University, Seoul, Korea
| | - Yichao Zhang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Pinshane Y Huang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA
| | | | - Miyoung Kim
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea
| | - Gwan-Hyoung Lee
- Department of Material Science and Engineering, Seoul National University, Seoul, Korea.
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5
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Aftab S, Hussain S, Al-Kahtani AA. Latest Innovations in 2D Flexible Nanoelectronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2301280. [PMID: 37104492 DOI: 10.1002/adma.202301280] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/30/2023] [Indexed: 06/19/2023]
Abstract
2D materials with dangling-bond-free surfaces and atomically thin layers have been shown to be capable of being incorporated into flexible electronic devices. The electronic and optical properties of 2D materials can be tuned or controlled in other ways by using the intriguing strain engineering method. The latest and encouraging techniques in regard to creating flexible 2D nanoelectronics are condensed in this review. These techniques have the potential to be used in a wider range of applications in the near and long term. It is possible to use ultrathin 2D materials (graphene, BP, WTe2 , VSe2 etc.) and 2D transition metal dichalcogenides (2D TMDs) in order to enable the electrical behavior of the devices to be studied. A category of materials is produced on smaller scales by exfoliating bulk materials, whereas chemical vapor deposition (CVD) and epitaxial growth are employed on larger scales. This overview highlights two distinct requirements, which include from a single semiconductor or with van der Waals heterostructures of various nanomaterials. They include where strain must be avoided and where it is required, such as solutions to produce strain-insensitive devices, and such as pressure-sensitive outcomes, respectively. Finally, points-of-view about the current difficulties and possibilities in regard to using 2D materials in flexible electronics are provided.
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Affiliation(s)
- Sikandar Aftab
- Department of Intelligent Mechatronics Engineering, Sejong University, Seoul, 05006, South Korea
| | - Sajjad Hussain
- Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul, 05006, South Korea
| | - Abdullah A Al-Kahtani
- Chemistry Department, Collage of Science, King Saud University, P. O. Box 2455, Riyadh, 11451, Saudi Arabia
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6
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Abramov AN, Chestnov IY, Alimova ES, Ivanova T, Mukhin IS, Krizhanovskii DN, Shelykh IA, Iorsh IV, Kravtsov V. Photoluminescence imaging of single photon emitters within nanoscale strain profiles in monolayer WSe 2. Nat Commun 2023; 14:5737. [PMID: 37714836 PMCID: PMC10504242 DOI: 10.1038/s41467-023-41292-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 08/29/2023] [Indexed: 09/17/2023] Open
Abstract
Local deformation of atomically thin van der Waals materials provides a powerful approach to create site-controlled chip-compatible single-photon emitters (SPEs). However, the microscopic mechanisms underlying the formation of such strain-induced SPEs are still not fully clear, which hinders further efforts in their deterministic integration with nanophotonic structures for developing practical on-chip sources of quantum light. Here we investigate SPEs with single-photon purity up to 98% created in monolayer WSe2 via nanoindentation. Using photoluminescence imaging in combination with atomic force microscopy, we locate single-photon emitting sites on a deep sub-wavelength spatial scale and reconstruct the details of the surrounding local strain potential. The obtained results suggest that the origin of the observed single-photon emission is likely related to strain-induced spectral shift of dark excitonic states and their hybridization with localized states of individual defects.
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Affiliation(s)
- Artem N Abramov
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
| | - Igor Y Chestnov
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
| | - Ekaterina S Alimova
- Peter The Great St. Petersburg Polytechnic University, Saint Petersburg, 195251, Russia
| | - Tatiana Ivanova
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
| | - Ivan S Mukhin
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
- St. Petersburg Academic University, Saint Petersburg, 194021, Russia
| | | | - Ivan A Shelykh
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
- Science Institute, University of Iceland, Dunhagi-3, IS-107, Reykjavik, Iceland
- Abrikosov Center for Theoretical Physics, MIPT, Dolgoprudnyi, Moscow Region, 141701, Russia
- Russian Quantum Center, Skolkovo, Moscow, 143025, Russia
| | - Ivan V Iorsh
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
- Abrikosov Center for Theoretical Physics, MIPT, Dolgoprudnyi, Moscow Region, 141701, Russia
- Russian Quantum Center, Skolkovo, Moscow, 143025, Russia
| | - Vasily Kravtsov
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia.
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7
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Zhao S, Li Z, Huang X, Rupp A, Göser J, Vovk IA, Kruchinin SY, Watanabe K, Taniguchi T, Bilgin I, Baimuratov AS, Högele A. Excitons in mesoscopically reconstructed moiré heterostructures. NATURE NANOTECHNOLOGY 2023; 18:572-579. [PMID: 36973398 DOI: 10.1038/s41565-023-01356-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Moiré effects in vertical stacks of two-dimensional crystals give rise to new quantum materials with rich transport and optical phenomena that originate from modulations of atomic registries within moiré supercells. Due to finite elasticity, however, the superlattices can transform from moiré-type to periodically reconstructed patterns. Here we expand the notion of such nanoscale lattice reconstruction to the mesoscopic scale of laterally extended samples and demonstrate rich consequences in optical studies of excitons in MoSe2-WSe2 heterostructures with parallel and antiparallel alignments. Our results provide a unified perspective on moiré excitons in near-commensurate semiconductor heterostructures with small twist angles by identifying domains with exciton properties of distinct effective dimensionality, and establish mesoscopic reconstruction as a compelling feature of real samples and devices with inherent finite size effects and disorder. Generalized to stacks of other two-dimensional materials, this notion of mesoscale domain formation with emergent topological defects and percolation networks will instructively expand the understanding of fundamental electronic, optical and magnetic properties of van der Waals heterostructures.
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Affiliation(s)
- Shen Zhao
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Munich, Germany.
| | - Zhijie Li
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Xin Huang
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Munich, Germany
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, P. R. China
- School of Physical Sciences, CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing, P. R. China
| | - Anna Rupp
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Jonas Göser
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Ilia A Vovk
- PhysNano Department, ITMO University, Saint Petersburg, Russia
| | - Stanislav Yu Kruchinin
- Center for Computational Materials Sciences, Faculty of Physics, University of Vienna, Vienna, Austria
- Nuance Communications Austria GmbH, Vienna, Austria
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Ismail Bilgin
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Munich, Germany
| | - Anvar S Baimuratov
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Munich, Germany.
| | - Alexander Högele
- Fakultät für Physik, Munich Quantum Center, and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Munich, Germany.
- Munich Center for Quantum Science and Technology (MCQST), München, Germany.
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8
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Wang X, Pettes MT, Wang Y, Zhu JX, Dhall R, Song C, Jones AC, Ciston J, Yoo J. Enhanced Exciton-to-Trion Conversion by Proton Irradiation of Atomically Thin WS 2. NANO LETTERS 2023; 23:3754-3761. [PMID: 37094221 DOI: 10.1021/acs.nanolett.2c04987] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Defect engineering of van der Waals semiconductors has been demonstrated as an effective approach to manipulate the structural and functional characteristics toward dynamic device controls, yet correlations between physical properties with defect evolution remain underexplored. Using proton irradiation, we observe an enhanced exciton-to-trion conversion of the atomically thin WS2. The altered excitonic states are closely correlated with nanopore induced atomic displacement, W nanoclusters, and zigzag edge terminations, verified by scanning transmission electron microscopy, photoluminescence, and Raman spectroscopy. Density functional theory calculation suggests that nanopores facilitate formation of in-gap states that act as sinks for free electrons to couple with excitons. The ion energy loss simulation predicts a dominating electron ionization effect upon proton irradiation, providing further evidence on band perturbations and nanopore formation without destroying the overall crystallinity. This study provides a route in tuning the excitonic properties of van der Waals semiconductors using an irradiation-based defect engineering approach.
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Affiliation(s)
- Xuejing Wang
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Michael Thompson Pettes
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Yongqiang Wang
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Materials Science in Radiation and Dynamics Extremes (MST-8), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Jian-Xin Zhu
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Physics of Condensed Matter and Complex Systems (T-4), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Rohan Dhall
- National Center for Electron Microscopy (NCEM), Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Chengyu Song
- National Center for Electron Microscopy (NCEM), Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Andrew C Jones
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Jim Ciston
- National Center for Electron Microscopy (NCEM), Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jinkyoung Yoo
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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9
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Fan J, Sun M. Transition Metal Dichalcogenides (TMDCs) Heterostructures: Synthesis, Excitons and Photoelectric Properties. CHEM REC 2022; 22:e202100313. [PMID: 35452180 DOI: 10.1002/tcr.202100313] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/22/2022] [Accepted: 04/11/2022] [Indexed: 11/06/2022]
Abstract
Transition metal dichalcogenides (TMDCs) have good flexibility, light absorption, and carrier mobility, and can be used to fabricate wearable devices and photodetectors. In addition, the band gaps of these materials are adjustable, which are related to the number of stacking layers. The the material properties can be changed by vertically stacking TMDCs to form van der Waals (vdW) heterostructures. Compared with single-layer TMDC, the vdW heterostructure has better light response and more efficient photoelectric conversion. Interlayer excitons formed in vdW heterostructure have a longer exciton lifetime and unique valley selectivity compared with intralayer excitons, which promotes the research on TMDCs materials in photoelectric field, valley electronics, carrier dynamics, etc. In this paper, the methods of synthesizing heterostructures are introduced. Photoelectric properties, valley dynamics, electronic properties and related applications of TMDCs vdW heterostructures are also discussed. Heterostructures stacked with different materials, stacking modes, and twist angles all can affect the properties. Hence, it brings more creativity and research direction to the material field.
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Affiliation(s)
- Jianuo Fan
- School of Mathematics and Physics, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China
| | - Mengtao Sun
- School of Mathematics and Physics, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China
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10
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Blackburn TJ, Tyler SM, Pemberton JE. Optical Spectroscopy of Surfaces, Interfaces, and Thin Films. Anal Chem 2022; 94:515-558. [DOI: 10.1021/acs.analchem.1c05323] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Thomas J. Blackburn
- Department of Chemistry and Biochemistry, University of Arizona, 1306 East University Boulevard, Tucson, Arizona 85721, United States
| | - Sarah M. Tyler
- Department of Chemistry and Biochemistry, University of Arizona, 1306 East University Boulevard, Tucson, Arizona 85721, United States
| | - Jeanne E. Pemberton
- Department of Chemistry and Biochemistry, University of Arizona, 1306 East University Boulevard, Tucson, Arizona 85721, United States
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11
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Baek H, Brotons-Gisbert M, Campbell A, Vitale V, Lischner J, Watanabe K, Taniguchi T, Gerardot BD. Optical read-out of Coulomb staircases in a moiré superlattice via trapped interlayer trions. NATURE NANOTECHNOLOGY 2021; 16:1237-1243. [PMID: 34556832 PMCID: PMC8592839 DOI: 10.1038/s41565-021-00970-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 07/26/2021] [Indexed: 05/21/2023]
Abstract
Moiré patterns with a superlattice potential can be formed by vertically stacking two layered materials with a relative twist or lattice constant mismatch. In transition metal dichalcogenide-based systems, the moiré potential landscape can trap interlayer excitons (IXs) at specific atomic registries. Here, we report that spatially isolated trapped IXs in a molybdenum diselenide/tungsten diselenide heterobilayer device provide a sensitive optical probe of carrier filling in their immediate environment. By mapping the spatial positions of individual trapped IXs, we are able to spectrally track the emitters as the moiré lattice is filled with excess carriers. Upon initial doping of the heterobilayer, neutral trapped IXs form charged IXs (IX trions) uniformly with a binding energy of ~7 meV. Upon further doping, the empty superlattice sites sequentially fill, creating a Coulomb staircase: stepwise changes in the IX trion emission energy due to Coulomb interactions with carriers at nearest-neighbour moiré sites. This non-invasive, highly local technique can complement transport and non-local optical sensing techniques to characterize Coulomb interaction energies, visualize charge correlated states, or probe local disorder in a moiré superlattice.
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Affiliation(s)
- Hyeonjun Baek
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK.
| | - Mauro Brotons-Gisbert
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK
| | - Aidan Campbell
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK
| | - Valerio Vitale
- Departments of Materials and Physics and the Thomas Young Centre for Theory and Simulation of Materials, Imperial College London, London, UK
| | - Johannes Lischner
- Departments of Materials and Physics and the Thomas Young Centre for Theory and Simulation of Materials, Imperial College London, London, UK
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Brian D Gerardot
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, UK.
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12
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Wang Q, Maisch J, Tang F, Zhao D, Yang S, Joos R, Portalupi SL, Michler P, Smet JH. Highly Polarized Single Photons from Strain-Induced Quasi-1D Localized Excitons in WSe 2. NANO LETTERS 2021; 21:7175-7182. [PMID: 34424710 PMCID: PMC8431731 DOI: 10.1021/acs.nanolett.1c01927] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/13/2021] [Indexed: 05/31/2023]
Abstract
Single photon emission from localized excitons in two-dimensional (2D) materials has been extensively investigated because of its relevance for quantum information applications. Prerequisites are the availability of photons with high purity polarization and controllable polarization orientation that can be integrated with optical cavities. Here, deformation strain along edges of prepatterned square-shaped substrate protrusions is exploited to induce quasi-one-dimensional (1D) localized excitons in WSe2 monolayers as an elegant way to get photons that fulfill these requirements. At zero magnetic field, the emission is linearly polarized with 95% purity because exciton states are valley hybridized with equal shares of both valleys and predominant emission from excitons with a dipole moment along the elongated direction. In a strong field, one valley is favored and the linear polarization is converted to high-purity circular polarization. This deterministic control over polarization purity and orientation is a valuable asset in the context of integrated quantum photonics.
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Affiliation(s)
- Qixing Wang
- Max
Planck Institute for Solid State Research, Stuttgart D-70569, Germany
| | - Julian Maisch
- Institut
für Halbleiteroptik und Funktionelle Grenzflächen, Center
for Integrated Quantum Science and Technology (IQST) and SCoPE, University of Stuttgart, Stuttgart D-70569, Germany
| | - Fangdong Tang
- Max
Planck Institute for Solid State Research, Stuttgart D-70569, Germany
| | - Dong Zhao
- Max
Planck Institute for Solid State Research, Stuttgart D-70569, Germany
| | - Sheng Yang
- Max
Planck Institute for Solid State Research, Stuttgart D-70569, Germany
| | - Raphael Joos
- Institut
für Halbleiteroptik und Funktionelle Grenzflächen, Center
for Integrated Quantum Science and Technology (IQST) and SCoPE, University of Stuttgart, Stuttgart D-70569, Germany
| | - Simone Luca Portalupi
- Institut
für Halbleiteroptik und Funktionelle Grenzflächen, Center
for Integrated Quantum Science and Technology (IQST) and SCoPE, University of Stuttgart, Stuttgart D-70569, Germany
| | - Peter Michler
- Institut
für Halbleiteroptik und Funktionelle Grenzflächen, Center
for Integrated Quantum Science and Technology (IQST) and SCoPE, University of Stuttgart, Stuttgart D-70569, Germany
| | - Jurgen H. Smet
- Max
Planck Institute for Solid State Research, Stuttgart D-70569, Germany
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13
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Alexeev EM, Mullin N, Ares P, Nevison-Andrews H, Skrypka O, Godde T, Kozikov A, Hague L, Wang Y, Novoselov KS, Fumagalli L, Hobbs JK, Tartakovskii AI. Emergence of Highly Linearly Polarized Interlayer Exciton Emission in MoSe 2/WSe 2 Heterobilayers with Transfer-Induced Layer Corrugation. ACS NANO 2020; 14:11110-11119. [PMID: 32803959 DOI: 10.1021/acsnano.0c01146] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The availability of accessible fabrication methods based on deterministic transfer of atomically thin crystals has been essential for the rapid expansion of research into van der Waals heterostructures. An inherent issue of these techniques is the deformation of the polymer carrier film during the transfer, which can lead to highly nonuniform strain induced in the transferred two-dimensional material. Here, using a combination of optical spectroscopy, atomic force, and Kelvin probe force microscopy, we show that the presence of nanometer scale wrinkles formed due to transfer-induced stress relaxation can lead to strong changes in the optical properties of MoSe2/WSe2 heterostructures and the emergence of linearly polarized interlayer exciton photoluminescence. We attribute these changes to local breaking of crystal symmetry in the nanowrinkles, which act as efficient accumulation centers for interlayer excitons due to the strain-induced interlayer band gap reduction. Surface potential images of the rippled heterobilayer samples acquired using Kelvin probe force microscopy reveal variations of the local work function consistent with strain-induced band gap modulation, while the potential offset observed at the ridges of the wrinkles shows a clear correlation with the value of the tensile strain estimated from the wrinkle geometry. Our findings highlight the important role of the residual strain in defining optical properties of van der Waals heterostructures and suggest effective approaches for interlayer exciton manipulation by local strain engineering.
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Affiliation(s)
- Evgeny M Alexeev
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Nic Mullin
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Pablo Ares
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- National Graphene Institute, University of Manchester, Booth Street East, Manchester M13 9PL, United Kingdom
| | - Harriet Nevison-Andrews
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- National Graphene Institute, University of Manchester, Booth Street East, Manchester M13 9PL, United Kingdom
| | - Oleksandr Skrypka
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Tillmann Godde
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
| | - Aleksey Kozikov
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- National Graphene Institute, University of Manchester, Booth Street East, Manchester M13 9PL, United Kingdom
| | - Lee Hague
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- National Graphene Institute, University of Manchester, Booth Street East, Manchester M13 9PL, United Kingdom
| | - Yibo Wang
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- National Graphene Institute, University of Manchester, Booth Street East, Manchester M13 9PL, United Kingdom
| | - Kostya S Novoselov
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- National Graphene Institute, University of Manchester, Booth Street East, Manchester M13 9PL, United Kingdom
- Centre for Advanced 2D Materials, National University of Singapore, 117546 Singapore
- Chongqing 2D Materials Institute, Liangjiang New Area, Chongqing, 400714 China
| | - Laura Fumagalli
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- National Graphene Institute, University of Manchester, Booth Street East, Manchester M13 9PL, United Kingdom
| | - Jamie K Hobbs
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
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