1
|
Choi J, Crust KJ, Li L, Lee K, Luo J, So JP, Watanabe K, Taniguchi T, Hwang HY, Mak KF, Shan J, Fuchs GD. Tuning Exciton Emission via Ferroelectric Polarization at a Heterogeneous Interface between a Monolayer Transition Metal Dichalcogenide and a Perovskite Oxide Membrane. NANO LETTERS 2024; 24:8948-8955. [PMID: 38996059 DOI: 10.1021/acs.nanolett.4c01853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2024]
Abstract
We demonstrate the integration of a thin BaTiO3 (BTO) membrane with monolayer MoSe2 in a dual-gate device that enables in situ manipulation of the BTO ferroelectric polarization with a voltage pulse. While two-dimensional (2D) transition metal dichalcogenides (TMDs) offer remarkable adaptability, their hybrid integration with other families of functional materials beyond the realm of 2D materials has been challenging. Released functional oxide membranes offer a solution for 2D/3D integration via stacking. 2D TMD excitons can serve as a local probe of the ferroelectric polarization in BTO at a heterogeneous interface. Using photoluminescence (PL) of MoSe2 excitons to optically read out the doping level, we find that the relative population of charge carriers in MoSe2 depends sensitively on the ferroelectric polarization. This finding points to a promising avenue for future-generation versatile sensing devices with high sensitivity, fast readout, and diverse applicability for advanced signal processing.
Collapse
Affiliation(s)
- Jaehong Choi
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850, United States
| | - Kevin J Crust
- Department of Physics, Stanford University, Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Lizhong Li
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850, United States
| | - Kihong Lee
- Department of Physics, Cornell University, Ithaca, New York 14850, United States
| | - Jialun Luo
- Department of Physics, Cornell University, Ithaca, New York 14850, United States
| | - Jae-Pil So
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850, United States
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Harold Y Hwang
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Department of Applied Physics, Stanford University, Stanford, California 94305, United States
| | - Kin Fai Mak
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850, United States
- Department of Physics, Cornell University, Ithaca, New York 14850, United States
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14850, United States
| | - Jie Shan
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850, United States
- Department of Physics, Cornell University, Ithaca, New York 14850, United States
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14850, United States
| | - Gregory D Fuchs
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14850, United States
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14850, United States
| |
Collapse
|
2
|
Chen S, Zhang Y, King WP, Bashir R, van der Zande AM. Edge-Passivated Monolayer WSe 2 Nanoribbon Transistors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2313694. [PMID: 39023387 DOI: 10.1002/adma.202313694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 07/06/2024] [Indexed: 07/20/2024]
Abstract
The ongoing reduction in transistor sizes drives advancements in information technology. However, as transistors shrink to the nanometer scale, surface and edge states begin to constrain their performance. 2D semiconductors like transition metal dichalcogenides (TMDs) have dangling-bond-free surfaces, hence achieving minimal surface states. Nonetheless, edge state disorder still limits the performance of width-scaled 2D transistors. This work demonstrates a facile edge passivation method to enhance the electrical properties of monolayer WSe2 nanoribbons, by combining scanning transmission electron microscopy, optical spectroscopy, and field-effect transistor (FET) transport measurements. Monolayer WSe2 nanoribbons are passivated with amorphous WOxSey at the edges, which is achieved using nanolithography and a controlled remote O2 plasma process. The same nanoribbons, with and without edge passivation are sequentially fabricated and measured. The passivated-edge nanoribbon FETs exhibit 10 ± 6 times higher field-effect mobility than the open-edge nanoribbon FETs, which are characterized with dangling bonds at the edges. WOxSey edge passivation minimizes edge disorder and enhances the material quality of WSe2 nanoribbons. Owing to its simplicity and effectiveness, oxidation-based edge passivation could become a turnkey manufacturing solution for TMD nanoribbons in beyond-silicon electronics and optoelectronics.
Collapse
Affiliation(s)
- Sihan Chen
- Holonyak Micro and Nanotechnology Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Yue Zhang
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - William P King
- Holonyak Micro and Nanotechnology Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Rashid Bashir
- Holonyak Micro and Nanotechnology Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Arend M van der Zande
- Holonyak Micro and Nanotechnology Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| |
Collapse
|
3
|
Gao H, Wang Z, Cao J, Lin YC, Ling X. Advancing Nanoelectronics Applications: Progress in Non-van der Waals 2D Materials. ACS NANO 2024; 18:16343-16358. [PMID: 38899467 DOI: 10.1021/acsnano.4c01177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Extending the inventory of two-dimensional (2D) materials remains highly desirable, given their excellent properties and wide applications. Current studies on 2D materials mainly focus on the van der Waals (vdW) materials since the discovery of graphene, where properties of atomically thin layers have been found to be distinct from their bulk counterparts. Beyond vdW materials, there are abundant non-vdW materials that can also be thinned down to 2D forms, which are still in their early stage of exploration. In this review, we focus on the downscaling of non-vdW materials into 2D forms to enrich the 2D materials family. This underexplored group of 2D materials could show potential promise in many areas such as electronics, optics, and magnetics, as has happened in the vdW 2D materials. Hereby, we will focus our discussion on their electronic properties and applications of them. We aim to motivate and inspire fellow researchers in the 2D materials community to contribute to the development of 2D materials beyond the widely studied vdW layered materials for electronic device applications. We also give our insights into the challenges and opportunities to guide researchers who are desirous of working in this promising research area.
Collapse
Affiliation(s)
- Hongze Gao
- Department of Chemistry, Boston University 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Zifan Wang
- Department of Chemistry, Boston University 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Jun Cao
- Department of Chemistry, Boston University 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Yuxuan Cosmi Lin
- Department of Materials Science and Engineering, Texas A&M University 575 Ross Street, College Station, Texas 77843, United States
| | - Xi Ling
- Department of Chemistry, Boston University 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
- Division of Materials Science and Engineering, Boston University 15 St Mary's Street, Boston, Massachusetts 02215, United States
| |
Collapse
|
4
|
Dong W, Dai Z, Liu L, Zhang Z. Toward Clean 2D Materials and Devices: Recent Progress in Transfer and Cleaning Methods. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2303014. [PMID: 38049925 DOI: 10.1002/adma.202303014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 08/30/2023] [Indexed: 12/06/2023]
Abstract
Two-dimensional (2D) materials have tremendous potential to revolutionize the field of electronics and photonics. Unlocking such potential, however, is hampered by the presence of contaminants that usually impede the performance of 2D materials in devices. This perspective provides an overview of recent efforts to develop clean 2D materials and devices. It begins by discussing conventional and recently developed wet and dry transfer techniques and their effectiveness in maintaining material "cleanliness". Multi-scale methodologies for assessing the cleanliness of 2D material surfaces and interfaces are then reviewed. Finally, recent advances in passive and active cleaning strategies are presented, including the unique self-cleaning mechanism, thermal annealing, and mechanical treatment that rely on self-cleaning in essence. The crucial role of interface wetting in these methods is emphasized, and it is hoped that this understanding can inspire further extension and innovation of efficient transfer and cleaning of 2D materials for practical applications.
Collapse
Affiliation(s)
- Wenlong Dong
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication and CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhaohe Dai
- Department of Mechanics and Engineering Science, State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing, 100871, China
| | - Luqi Liu
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication and CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Zhong Zhang
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027, China
| |
Collapse
|
5
|
Kumar P, Chen J, Meng AC, Yang WCD, Anantharaman SB, Horwath JP, Idrobo JC, Mishra H, Liu Y, Davydov AV, Stach EA, Jariwala D. Observation of Sub-10 nm Transition Metal Dichalcogenide Nanocrystals in Rapidly Heated van der Waals Heterostructures. ACS APPLIED MATERIALS & INTERFACES 2023; 15:59693-59703. [PMID: 38090759 DOI: 10.1021/acsami.3c13471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Two-dimensional materials, such as transition metal dichalcogenides (TMDCs), have the potential to revolutionize the field of electronics and photonics due to their unique physical and structural properties. This research presents a novel method for synthesizing crystalline TMDCs crystals with <10 nm size using ultrafast migration of vacancies at elevated temperatures. Through in situ and ex situ processing and using atomic-level characterization techniques, we analyzed the shape, size, crystallinity, composition, and strain distribution of these nanocrystals. These nanocrystals exhibit electronic structure signatures that differ from the 2D bulk: i.e., uniform mono- and multilayers. Further, our in situ, vacuum-based synthesis technique allows observation and comparison of defect and phase evolution in these crystals formed under van der Waals heterostructure confinement versus unconfined conditions. Overall, this research demonstrates a solid-state route to synthesizing uniform nanocrystals of TMDCs and lays the foundation for materials science in confined 2D spaces under extreme conditions.
Collapse
Affiliation(s)
- Pawan Kumar
- Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Inter-university Microelectronics Center (IMEC), Leuven 3001, Belgium
| | - Jiazheng Chen
- Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Andrew C Meng
- Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Wei-Chang D Yang
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Surendra B Anantharaman
- Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Low-dimensional Semiconductors Lab, Metallurgical and Materials Engineering, Indian Institute of Technology-Madras, Chennai, Tamilnadu 600036, India
| | - James P Horwath
- Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Juan C Idrobo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Materials Science & Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Himani Mishra
- Department of Mechanical Engineering and Texas Materials Institute, University of Texas, Austin, Texas 78712, United States
| | - Yuanyue Liu
- Department of Mechanical Engineering and Texas Materials Institute, University of Texas, Austin, Texas 78712, United States
| | - Albert V Davydov
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Eric A Stach
- Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Deep Jariwala
- Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
6
|
Palai SK, Dyksik M, Sokolowski N, Ciorga M, Sánchez Viso E, Xie Y, Schubert A, Taniguchi T, Watanabe K, Maude DK, Surrente A, Baranowski M, Castellanos-Gomez A, Munuera C, Plochocka P. Approaching the Intrinsic Properties of Moiré Structures Using Atomic Force Microscopy Ironing. NANO LETTERS 2023. [PMID: 37276177 DOI: 10.1021/acs.nanolett.2c04765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Stacking monolayers of transition metal dichalcogenides (TMDs) has led to the discovery of a plethora of new exotic phenomena, resulting from moiré pattern formation. Due to the atomic thickness and high surface-to-volume ratio of heterostructures, the interfaces play a crucial role. Fluctuations in the interlayer distance affect interlayer coupling and moiré effects. Therefore, to access the intrinsic properties of the TMD stack, it is essential to obtain a clean and uniform interface between the layers. Here, we show that this is achieved by ironing with the tip of an atomic force microscope. This post-stacking procedure dramatically improves the homogeneity of the interfaces, which is reflected in the optical response of the interlayer exciton. We demonstrate that ironing improves the layer coupling, enhancing moiré effects and reducing disorder. This is crucial for the investigation of TMD heterostructure physics, which currently suffers from low reproducibility.
Collapse
Affiliation(s)
- Swaroop Kumar Palai
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse 3, INSA-T, 31400 Toulouse, France
| | - Mateusz Dyksik
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370 Wrocław, Poland
| | - Nikodem Sokolowski
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse 3, INSA-T, 31400 Toulouse, France
| | - Mariusz Ciorga
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370 Wrocław, Poland
| | - Estrella Sánchez Viso
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Yong Xie
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Alina Schubert
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-004, Japan
| | - Duncan K Maude
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse 3, INSA-T, 31400 Toulouse, France
| | - Alessandro Surrente
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370 Wrocław, Poland
| | - Michał Baranowski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-370 Wrocław, Poland
| | - Andres Castellanos-Gomez
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Carmen Munuera
- Materials Science Factory, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Madrid E-28049, Spain
| | - Paulina Plochocka
- Laboratoire National des Champs Magnétiques Intenses, EMFL, CNRS UPR 3228, Université Toulouse, Université Toulouse 3, INSA-T, 31400 Toulouse, France
| |
Collapse
|
7
|
Thoutam LR, Mathew R, Ajayan J, Tayal S, Nair SV. A critical review of fabrication challenges and reliability issues in top/bottom gated MoS 2field-effect transistors. NANOTECHNOLOGY 2023; 34:232001. [PMID: 36731113 DOI: 10.1088/1361-6528/acb826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
The voyage of semiconductor industry to decrease the size of transistors to achieve superior device performance seems to near its physical dimensional limitations. The quest is on to explore emerging material systems that offer dimensional scaling to match the silicon- based technologies. The discovery of atomic flat two-dimensional materials has opened up a completely new avenue to fabricate transistors at sub-10 nanometer level which has the potential to compete with modern silicon-based semiconductor devices. Molybdenum disulfide (MoS2) is a two-dimensional layered material with novel semiconducting properties at atomic level seems like a promising candidate that can possibly meet the expectation of Moore's law. This review discusses the various 'fabrication challenges' in making MoS2based electronic devices from start to finish. The review outlines the intricate challenges of substrate selection and various synthesis methods of mono layer and few-layer MoS2. The review focuses on the various techniques and methods to minimize interface defect density at substrate/MoS2interface for optimum MoS2-based device performance. The tunable band-gap of MoS2with varying thickness presents a unique opportunity for contact engineering to mitigate the contact resistance issue using different elemental metals. In this work, we present a comprehensive overview of different types of contact materials with myriad geometries that show a profound impact on device performance. The choice of different insulating/dielectric gate oxides on MoS2in co-planar and vertical geometry is critically reviewed and the physical feasibility of the same is discussed. The experimental constraints of different encapsulation techniques on MoS2and its effect on structural and electronic properties are extensively discussed.
Collapse
Affiliation(s)
- Laxman Raju Thoutam
- Amrita School of Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Ponekkara, Kochi 682041, India
| | - Ribu Mathew
- School of Electrical & Electronics Engineering, VIT Bhopal University, Bhopal, 466114, India
| | - J Ajayan
- Department of Electronics and Communication Engineering, SR University, Warangal, 506371, India
| | - Shubham Tayal
- Department of Electronics and Communication Engineering, SR University, Warangal, 506371, India
| | - Shantikumar V Nair
- Amrita School of Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Ponekkara, Kochi 682041, India
| |
Collapse
|
8
|
Bisswanger T, Winter Z, Schmidt A, Volmer F, Watanabe K, Taniguchi T, Stampfer C, Beschoten B. CVD Bilayer Graphene Spin Valves with 26 μm Spin Diffusion Length at Room Temperature. NANO LETTERS 2022; 22:4949-4955. [PMID: 35649273 DOI: 10.1021/acs.nanolett.2c01119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We present inverted spin-valve devices fabricated from chemical vapor deposition (CVD)-grown bilayer graphene (BLG) that show more than a doubling in device performance at room temperature compared to state-of-the-art bilayer graphene spin valves. This is made possible by a polydimethylsiloxane droplet-assisted full-dry transfer technique that compensates for previous process drawbacks in device fabrication. Gate dependent Hanle measurements reveal spin lifetimes of up to 5.8 ns and a spin diffusion length of up to 26 μm at room temperature combined with a charge carrier mobility of about 24 000 cm2(V s)-1 for the best device. Our results demonstrate that CVD-grown BLG shows equally good room temperature spin transport properties as both CVD-grown single-layer graphene and even exfoliated single-layer graphene.
Collapse
Affiliation(s)
- Timo Bisswanger
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
| | - Zachary Winter
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
| | - Anne Schmidt
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
| | - Frank Volmer
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Christoph Stampfer
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
- Peter Grünberg Institute (PGI-9) Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Bernd Beschoten
- 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
| |
Collapse
|
9
|
Kim S, Moon D, Jeon BR, Yeon J, Li X, Kim S. Accurate Atomic-Scale Imaging of Two-Dimensional Lattices Using Atomic Force Microscopy in Ambient Conditions. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:1542. [PMID: 35564252 PMCID: PMC9104726 DOI: 10.3390/nano12091542] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 02/04/2023]
Abstract
To facilitate the rapid development of van der Waals materials and heterostructures, scanning probe methods capable of nondestructively visualizing atomic lattices and moiré superlattices are highly desirable. Lateral force microscopy (LFM), which measures nanoscale friction based on the commonly available atomic force microscopy (AFM), can be used for imaging a wide range of two-dimensional (2D) materials, but imaging atomic lattices using this technique is difficult. Here, we examined a number of the common challenges encountered in LFM experiments and presented a universal protocol for obtaining reliable atomic-scale images of 2D materials under ambient environment. By studying a series of LFM images of graphene and transition metal dichalcogenides (TMDs), we have found that the accuracy and the contrast of atomic-scale images critically depended on several scanning parameters including the scan size and the scan rate. We applied this protocol to investigate the atomic structure of the ripped and self-folded edges of graphene and have found that these edges were mostly in the armchair direction. This finding is consistent with the results of several simulations results. Our study will guide the extensive effort on assembly and characterization of new 2D materials and heterostructures.
Collapse
Affiliation(s)
- Sunghyun Kim
- Department of Applied Physics, Hanyang University, Ansan 15588, Korea; (S.K.); (B.R.J.); (J.Y.)
| | - Donghyeon Moon
- Department of Photonics and Nanoelectronics, Hanyang University, Ansan 15588, Korea;
| | - Bo Ram Jeon
- Department of Applied Physics, Hanyang University, Ansan 15588, Korea; (S.K.); (B.R.J.); (J.Y.)
| | - Jegyeong Yeon
- Department of Applied Physics, Hanyang University, Ansan 15588, Korea; (S.K.); (B.R.J.); (J.Y.)
| | - Xiaoqin Li
- Center for Complex Quantum Systems, Department of Physics, The University of Texas at Austin, Austin, TX 78712, USA;
- Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA
| | - Suenne Kim
- Department of Photonics and Nanoelectronics, Hanyang University, Ansan 15588, Korea;
| |
Collapse
|
10
|
Chang H, Wang H, Song KK, Zhong M, Shi LB, Qian P. Origin of phonon-limited mobility in two-dimensional metal dichalcogenides. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 34:013003. [PMID: 34714257 DOI: 10.1088/1361-648x/ac29e1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
Metal dichalcogenides are novel two-dimensional (2D) semiconductors after the discovery of graphene. In this article, phonon-limited mobility for six kinds of 2D semiconductors with the composition of MX2is reviewed, in which M (Cr, Mo and W) is the transition metal, and X (S and Se) is the chalcogen element. The review is divided into three parts. In the first part, we briefly introduce the calculation method of mobility, including the empirical model and Boltzmann transport theory (BTE). The application scope, merits and limitations of these methods are summarized. In the second part, we explore empirical models to calculate the mobility of MX2, including longitudinal acoustic phonon, optical phonon (OP) and polar optical phonon (POP) models. The contribution of multi-valley to mobility is reviewed in the calculation. The differences between static and high-frequency dielectric constants (Δϵ) are only 0.13 and 0.03 for MoS2and WS2. Such a low value indicates that the polarization hardly changes in the external field. So, their mobility is not determined by POP, but by deformation potential models. Different from GaAs, POP scattering plays a decisive role in its mobility. Our investigations also reveal that the scattering from POP cannot be ignored in CrSe2, MoSe2and WSe2. In the third parts, we investigate the mobility of MX2using electron-phonon coupling matrix element, which is based on BTE from the framework of a many-body quantum-field theory. Valence band splitting of MoS2and WS2is induced by spin-orbit coupling effect, which leads to the increase of hole mobility. In particular, we review in detail the theoretical and experimental results of MoS2mobility in recent ten years, and its mobility is also compared with other materials to deepen the understanding.
Collapse
Affiliation(s)
- Hao Chang
- College of Physical Science and Technology, Bohai University, Jinzhou 121013, People's Republic of China
| | - Hao Wang
- College of Physical Science and Technology, Bohai University, Jinzhou 121013, People's Republic of China
| | - Ke-Ke Song
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Min Zhong
- Liaoning Key Laboratory of Optoelectronic Functional Materials Testing and Technology, College of Chemical and Material Engineering, Bohai University, Jinzhou 121013, People's Republic of China
| | - Li-Bin Shi
- College of Physical Science and Technology, Bohai University, Jinzhou 121013, People's Republic of China
| | - Ping Qian
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| |
Collapse
|
11
|
Schranghamer TF, Sharma M, Singh R, Das S. Review and comparison of layer transfer methods for two-dimensional materials for emerging applications. Chem Soc Rev 2021; 50:11032-11054. [PMID: 34397050 DOI: 10.1039/d1cs00706h] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Two-dimensional (2D) materials offer immense potential for scientific breakthroughs and technological innovations. While early demonstrations of 2D material-based electronics, optoelectronics, flextronics, straintronics, twistronics, and biomimetic devices exploited micromechanically-exfoliated single crystal flakes, recent years have witnessed steady progress in large-area growth techniques such as physical vapor deposition (PVD), chemical vapor deposition (CVD), and metal-organic CVD (MOCVD). However, use of high growth temperatures, chemically-active growth precursors and promoters, and the need for epitaxy often limit direct growth of 2D materials on the substrates of interest for commercial applications. This has led to the development of a large number of methods for the layer transfer of 2D materials from the growth substrate to the target application substrate with varying degrees of cleanliness, uniformity, and transfer-related damage. This review aims to catalog and discuss these layer transfer methods. In particular, the processes, advantages, and drawbacks of various transfer methods are discussed, as is their applicability to different technological platforms of interest for 2D material implementation.
Collapse
Affiliation(s)
- Thomas F Schranghamer
- Department of Engineering Science and Mechanics, Penn State University, University Park, PA 16802, USA.
| | - Madan Sharma
- Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Rajendra Singh
- Department of Physics, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Saptarshi Das
- Department of Engineering Science and Mechanics, Penn State University, University Park, PA 16802, USA. and Department of Materials Science and Engineering, Penn State University, University Park, PA 16802, USA and Materials Research Institute, Penn State University, University Park, PA 16802, USA
| |
Collapse
|