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Meng Q, Shi J, Zhang J, Liu Y, Wang W, Webster RF, Zhao D, Zhu Y, Hao B, Qu B, Lin X, Lin CH, Qiao L, Zu X, Huang JK, Li W, Wang D, Yang J, Li S. Elastic Properties of Low-Dimensional Single-Crystalline Dielectric Oxides through Controlled Large-Area Wrinkle Generation. ACS APPLIED MATERIALS & INTERFACES 2024; 16:28980-28990. [PMID: 38768264 DOI: 10.1021/acsami.4c00260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Freestanding single-crystalline SrTiO3 membranes, as high-κ dielectrics, hold significant promise as the gate dielectric in two-dimensional (2D) flexible electronics. Nevertheless, the mechanical properties of the SrTiO3 membranes, such as elasticity, remain a critical piece of the puzzle to adequately address the viability of their applications in flexible devices. Here, we report statistical analysis on plane-strain effective Young's modulus of large-area SrTiO3 membranes (5 × 5 mm2) over a series of thicknesses (from 6.5 to 32.2 nm), taking advantage of a highly efficient buckling-based method, which reveals its evident thickness-dependent behavior ranging from 46.01 to 227.17 GPa. Based on microscopic and theoretical results, we elucidate these thickness-dependent behaviors and statistical data deviation with a bilayer model, which consists of a surface layer and a bulk-like layer. The analytical results show that the ∼3.1 nm surface layer has a significant elastic softening compared to the bulk-like layer, while the extracted modulus of the bulk-like layer shows a variation of ∼40 GPa. This variation is considered as a combined contribution from oxygen deficiency presenting in SrTiO3 membranes, and the alignment between applied strain and the crystal orientation. Upon comparison of the extracted elastic properties and electrostatic control capability to those of other typical gate dielectrics, the superior performance of single-crystalline SrTiO3 membranes has been revealed in the context of flexible gate dielectrics, indicating the significant potential of their application in high-performance flexible 2D electronics.
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Affiliation(s)
- Qingxiao Meng
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Junjie Shi
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Ji Zhang
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Yang Liu
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Wenxuan Wang
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Richard F Webster
- Electron Microscope Unit, Mark Wainwright Analytical Centre, UNSW, Sydney 2052, NSW, Australia
| | - Duoduo Zhao
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Yanda Zhu
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Bohan Hao
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Bo Qu
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
- UNSW Materials & Manufacturing Futures Institute, UNSW, Sydney 2052, NSW, Australia
| | - Xi Lin
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
- UNSW Materials & Manufacturing Futures Institute, UNSW, Sydney 2052, NSW, Australia
| | - Chun-Ho Lin
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Liang Qiao
- School of Physics, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China
| | - Xiaotao Zu
- School of Physics, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, China
| | - Jing-Kai Huang
- Department of Systems Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong SAR, China
| | - Wenxian Li
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Danyang Wang
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
| | - Jack Yang
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
- UNSW Materials & Manufacturing Futures Institute, UNSW, Sydney 2052, NSW, Australia
| | - Sean Li
- School of Materials Science and Engineering, UNSW, Sydney 2052, NSW, Australia
- UNSW Materials & Manufacturing Futures Institute, UNSW, Sydney 2052, NSW, Australia
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Meganathan K, Mangamma G, Swaminadhan MJ, Murugan V, Shinde NB, Ghosh S, Eswaran SK. Thickness-Dependent Nanoscale Elastic Stiffening of Chemical Vapor Deposited Atomically Thin 2H-MoS 2 Films. J Phys Chem Lett 2024; 15:4206-4211. [PMID: 38598716 DOI: 10.1021/acs.jpclett.3c03512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Understanding the nanoscale elastic-size-effects of atomically thin transition-metal dichalcogenides (TMDs) as a function of thickness underpins the avenue of flexible 2D electronics. In this work, we employed the atomic force acoustic microscopy (AFAM) technique to investigate the thickness-dependent elastic properties of CVD grown 2H-MoS2 films. The monolayer MoS2 exhibited a Young's modulus of 273 ± 27 GPa. Our systematic analysis from bulk to monolayer suggests that the 2H-MoS2 phase exhibits nanoscale elastic-stiffening behavior with decreasing number of layers (thickness). The Young's modulus increased by a factor of ∼2.7 for monolayer MoS2 when compared with the bulk. First-principle DFT calculations affirm the nanoscale elastic-stiffening behavior of MoS2 with decreasing number of layers. Our findings suggest that the observed elastic stiffening is due to the interlayer sliding, which may be facilitated by defects in MoS2 layers. The observed elastic stiffening may be of potential importance for understanding TMD based nanomechanical devices.
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Affiliation(s)
- Kalaiarasan Meganathan
- 2D Materials and Devices Laboratory (2DML), Sir C. V. Raman Research Park, Department of Physics and Nanotechnology, SRM Institute of Science and Technology (SRMIST), Kattankulathur 603203, Chennai, India
| | - G Mangamma
- Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam 603102, Tamil Nadu, India
| | - M J Swaminadhan
- Materials Design Lab, Department of Physics and Nanotechnology, SRM Institute of Science and Technology (SRMIST), Kattankulathur 603203, Chennai, India
| | - Vijaykumar Murugan
- 2D Materials and Devices Laboratory (2DML), Sir C. V. Raman Research Park, Department of Physics and Nanotechnology, SRM Institute of Science and Technology (SRMIST), Kattankulathur 603203, Chennai, India
| | - Nitin Babu Shinde
- 2D Materials and Devices Laboratory (2DML), Sir C. V. Raman Research Park, Department of Physics and Nanotechnology, SRM Institute of Science and Technology (SRMIST), Kattankulathur 603203, Chennai, India
| | - Saurabh Ghosh
- Materials Design Lab, Department of Physics and Nanotechnology, SRM Institute of Science and Technology (SRMIST), Kattankulathur 603203, Chennai, India
| | - Senthil Kumar Eswaran
- 2D Materials and Devices Laboratory (2DML), Sir C. V. Raman Research Park, Department of Physics and Nanotechnology, SRM Institute of Science and Technology (SRMIST), Kattankulathur 603203, Chennai, India
- Nanotechnology Research Centre (NRC), SRM Institute of Science and Technology (SRMIST), Kattankulathur 603203, Chennai, India
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Uddin MM, Kabir MH, Ali MA, Hossain MM, Khandaker MU, Mandal S, Arifutzzaman A, Jana D. Graphene-like emerging 2D materials: recent progress, challenges and future outlook. RSC Adv 2023; 13:33336-33375. [PMID: 37964903 PMCID: PMC10641765 DOI: 10.1039/d3ra04456d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 09/18/2023] [Indexed: 11/16/2023] Open
Abstract
Owing to the unique physical and chemical properties of 2D materials and the great success of graphene in various applications, the scientific community has been influenced to explore a new class of graphene-like 2D materials for next-generation technological applications. Consequently, many alternative layered and non-layered 2D materials, including h-BN, TMDs, and MXenes, have been synthesized recently for applications related to the 4th industrial revolution. In this review, recent progress in state-of-the-art research on 2D materials, including their synthesis routes, characterization and application-oriented properties, has been highlighted. The evolving applications of 2D materials in the areas of electronics, optoelectronics, spintronic devices, sensors, high-performance and transparent electrodes, energy conversion and storage, electromagnetic interference shielding, hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and nanocomposites are discussed. In particular, the state-of-the-art applications, challenges, and outlook of every class of 2D material are also presented as concluding remarks to guide this fast-progressing class of 2D materials beyond graphene for scientific research into next-generation materials.
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Affiliation(s)
- Md Mohi Uddin
- Department of Physics, Chittagong University of Engineering and Technology Chattogram-4349 Bangladesh
| | - Mohammad Humaun Kabir
- Department of Physics, Chittagong University of Engineering and Technology Chattogram-4349 Bangladesh
| | - Md Ashraf Ali
- Department of Physics, Chittagong University of Engineering and Technology Chattogram-4349 Bangladesh
| | - Md Mukter Hossain
- Department of Physics, Chittagong University of Engineering and Technology Chattogram-4349 Bangladesh
| | - Mayeen Uddin Khandaker
- Faculty of Graduate Studies, Daffodil International University Daffodil Smart City, Birulia, Savar Dhaka 1216 Bangladesh
- Centre for Applied Physics and Radiation Technologies, School of Engineering and Technology, Sunway University 47500 Bandar Sunway Selangor Malaysia
| | - Sumit Mandal
- Vidyasagar College 39, Sankar Ghosh Lane Kolkata 700006 West Bengal India
| | - A Arifutzzaman
- Tyndall National Institute, University College Cork Lee Maltings Cork T12 R5CP Ireland
| | - Debnarayan Jana
- Department of Physics, University of Calcutta 92 A P C Road Kolkata 700009 West Bengal India
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Si J, Yu J, Lan H, Niu L, Luo J, Yu Y, Li L, Ding Y, Zeng M, Fu L. Chemical Potential-Modulated Ultrahigh-Phase-Purity Growth of Ultrathin Transition-Metal Boride Single Crystals. J Am Chem Soc 2023; 145:3994-4002. [PMID: 36706380 DOI: 10.1021/jacs.2c11139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Two-dimensional (2D) transition-metal borides (TMBs) are especially expected to exhibit excellent performance in various fields among electricity, superconductivity, magnetism, mechanics, biotechnology, battery, and catalysis. However, the synthesis of ultrathin TMB single crystals with ultrahigh phase purity was deemed extremely challenging and has not been realized till date. That is because TMBs have the most kinds of crystal structures among inorganic compounds, which possess generous phase structures with similar formation energies compared with other transition-metal compounds, attributing to the metalloid and electron-deficient characteristics of boron. Herein, for the first time, we demonstrate a chemical potential-modulated strategy to realize the precise synthesis of various ultrahigh-phase-purity (approximately 100%) ultrathin TMB single crystals, and the precision in the phase formation energy can reach as low as 0.01 eV per atom. The ultrathin MoB2 single crystals exhibit an ultrahigh Young's modulus of 517 GPa compared to other 2D materials. Our work establishes a chemical potential-modulated strategy to synthesize ultrathin single crystals with ultrahigh phase purity, especially those with similar formation energies, and undoubtedly provides excellent platforms for their extensive research and applications.
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Affiliation(s)
- Jingjing Si
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Jinqiu Yu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Haihui Lan
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Lixin Niu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Jingrui Luo
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Yantao Yu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Linyang Li
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Yu Ding
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Mengqi Zeng
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Lei Fu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
- The Institute for Advanced Studies (IAS), Wuhan University, Wuhan 430072, China
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Wang X, Tan J, Ouyang J, Zhang H, Wang J, Wang Y, Deringer VL, Zhou J, Zhang W, Ma E. Designing Inorganic Semiconductors with Cold-Rolling Processability. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203776. [PMID: 35981888 PMCID: PMC9596854 DOI: 10.1002/advs.202203776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/03/2022] [Indexed: 06/15/2023]
Abstract
While metals can be readily processed and reshaped by cold rolling, most bulk inorganic semiconductors are brittle materials that tend to fracture when plastically deformed. Manufacturing thin sheets and foils of inorganic semiconductors is therefore a bottleneck problem, severely restricting their use in flexible electronic applications. It is recently reported that a few single-crystalline 2D van der Waals (vdW) semiconductors, such as InSe, are deformable under compressive stress. Here it is demonstrated that intralayer fracture toughness can be tailored via compositional design to make inorganic semiconductors processable by cold rolling. Systematic ab initio calculations covering a range of van der Waals semiconductors homologous to InSe are reported, leading to material-property maps that forecast trends in both the susceptibility to interlayer slip and the intralayer fracture toughness against cracking. GaSe is predicted, and experimentally confirmed, to be practically amenable to being rolled to large (three quarters) thickness reduction and length extension by a factor of three. The fracture toughness and cleavage energy are predicted to be 0.25 MPa m0.5 and 15 meV Å-2 , respectively. The findings open a new realm of possibility for alloy selection and design toward processing-friendly group-III chalcogenides for practical applications.
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Affiliation(s)
- Xu‐Dong Wang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Jieling Tan
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Jian Ouyang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Hang‐Ming Zhang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Jiang‐Jing Wang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Yuecun Wang
- Center for Advancing Materials Performance from the Nanoscale (CAMP‐Nano) and Hysitron Applied Research Center in China (HARCC)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Volker L. Deringer
- Department of ChemistryInorganic Chemistry LaboratoryUniversity of OxfordOxfordOX1 3QRUK
| | - Jian Zhou
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Wei Zhang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - En Ma
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
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6
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Bao L, Huang L, Guo H, Gao HJ. Construction and physical properties of low-dimensional structures for nanoscale electronic devices. Phys Chem Chem Phys 2022; 24:9082-9117. [PMID: 35383791 DOI: 10.1039/d1cp05981e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over the past decades, construction of nanoscale electronic devices with novel functionalities based on low-dimensional structures, such as single molecules and two-dimensional (2D) materials, has been rapidly developed. To investigate their intrinsic properties for versatile functionalities of nanoscale electronic devices, it is crucial to precisely control the structures and understand the physical properties of low-dimensional structures at the single atomic level. In this review, we provide a comprehensive overview of the construction of nanoelectronic devices based on single molecules and 2D materials and the investigation of their physical properties. For single molecules, we focus on the construction of single-molecule devices, such as molecular motors and molecular switches, by precisely controlling their self-assembled structures on metal substrates and charge transport properties. For 2D materials, we emphasize their spin-related electrical transport properties for spintronic device applications and the role that interfaces among 2D semiconductors, contact electrodes, and dielectric substrates play in the electrical performance of electronic, optoelectronic, and memory devices. Finally, we discuss the future research direction in this field, where we can expect a scientific breakthrough.
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Affiliation(s)
- Lihong Bao
- Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, P. R. China. .,Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, P. R. China
| | - Li Huang
- Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
| | - Hui Guo
- Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
| | - Hong-Jun Gao
- Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, P. R. China. .,Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, P. R. China
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Wang G, Zhang Z, Wang Y, Gao E, Jia X, Dai Z, Weng C, Liu L, Zhang Y, Zhang Z. Out-of-Plane Deformations Determined Mechanics of Vanadium Disulfide (VS 2) Sheets. ACS APPLIED MATERIALS & INTERFACES 2021; 13:3040-3050. [PMID: 33400503 DOI: 10.1021/acsami.0c19835] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The rapid development of two-dimensional (2D) materials has significantly broadened the scope of 2D science in both fundamental scientific interests and emerging technological applications, wherein the mechanical properties play an indispensably key role. Nevertheless, particularly challenging is the ultrathin nature of 2D materials that makes their manipulations and characterizations considerably difficult. Herein, thanks to the excellent flexibility of vanadium disulfide (VS2) sheets, their susceptibility to out-of-plane deformation is exploited to realize the controllable loading and enable the accurate measurements of mechanical properties. In particular, the Young's modulus is estimated to be 44.4 ± 3.5 GPa, approaching the lower limit for 2D transition metal dichalcogenides (TMDs). We further report the first measurement of thickness-dependent bending rigidity of VS2, which deviates from the prediction of the classical continuum mechanics theory. Additionally, a deeper understanding of the mechanics within two dimensions also facilitates the modulation of strain-coupled physics at the nanoscale. Our Raman measurements showed the Grüneisen parameters for VS2 were determined for the first time to be γE2g1 ≈ 0.83 and γA1g ≈ 0.32.
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Affiliation(s)
- Guorui Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8, Canada
| | - Zhepeng Zhang
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, P. R. China
| | - Yanlei Wang
- State Key Laboratory of Multiphase Complex Systems, Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Enlai Gao
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, P. R. China
| | - Xiangzheng Jia
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, P. R. China
| | - Zhaohe Dai
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
| | - Chuanxin Weng
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
| | - Luqi Liu
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
| | - Yanfeng Zhang
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, P. R. China
| | - Zhong Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
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Wang X, Cui A, Chen F, Xu L, Hu Z, Jiang K, Shang L, Chu J. Probing Effective Out-of-Plane Piezoelectricity in van der Waals Layered Materials Induced by Flexoelectricity. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1903106. [PMID: 31550085 DOI: 10.1002/smll.201903106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/26/2019] [Indexed: 06/10/2023]
Abstract
Many van der Waals layered 2D materials, such as h-BN, transition metal dichalcogenides (TMDs), and group-III monochalcogenides, have been predicted to possess piezoelectric and mechanically flexible natures, which greatly motivates potential applications in piezotronic devices and nanogenerators. However, only intrinsic in-plane piezoelectricity exists in these 2D materials and the piezoelectric effect is confined in odd-layers of TMDs. The present work is intent on combining the free-standing design and piezoresponse force microscopy techniques to obtain and directly quantify the effective out-of-plane electromechanical coupling induced by strain gradient on atomically thin MoS2 and InSe flakes. Conspicuous piezoresponse and the measured piezoelectric coefficient with respect to the number of layers or thickness are systematically illustrated for both MoS2 and InSe flakes. Note that the promising effective piezoelectric coefficient (deff 33 ) of about 21.9 pm V-1 is observed on few-layered InSe. The out-of-plane piezoresponse arises from the net dipole moment along the normal direction of the curvature membrane induced by strain gradient. This work not only provides a feasible and flexible method to acquire and quantify the out-of-plane electromechanical coupling on van der Waals layered materials, but also paves the way to understand and tune the flexoelectric effect of 2D systems.
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Affiliation(s)
- Xiang Wang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Anyang Cui
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Fangfang Chen
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Liping Xu
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Zhigao Hu
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, Shanxi, China
- Shanghai Institute of Intelligent Electronics and Systems, Fudan University, Shanghai, 200433, China
| | - Kai Jiang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Liyan Shang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Junhao Chu
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, Shanxi, China
- Shanghai Institute of Intelligent Electronics and Systems, Fudan University, Shanghai, 200433, China
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