1
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Qi J, Dai Y, Ma C, Ke C, Wang W, Wu Z, Wang X, Bao K, Xu Y, Huang H, Wang L, Wu J, Luo G, Chen Y, Lin Z, He Q. Surfactant-Free Ultrasonication-Assisted Synthesis of 2d Tellurium Based on Metastable 1T'-MoTe 2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2306962. [PMID: 37652747 DOI: 10.1002/adma.202306962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/21/2023] [Indexed: 09/02/2023]
Abstract
Elemental 2D materials (E2DMs) have been attracting considerable attention owing to their chemical simplicity and excellent/exotic properties. However, the lack of robust chemical synthetic methods seriously limits their potential. Here, a surfactant-free liquid-phase synthesis of high-quality 2D tellurium is reported based on ultrasonication-assisted exfoliation of metastable 1T'-MoTe2. The as-grown 2D tellurium nanosheets exhibit excellent single crystallinity, ideal 2D morphology, surfactant-free surface, and negligible 1D by-products. Furthermore, a unique growth mechanism based on the atomic escape of Te atoms from metastable transition metal dichalcogenides and guided 2D growth in the liquid phase is proposed and verified. 2D tellurium-based field-effect transistors show ultrahigh hole mobility exceeding 1000 cm2 V-1 s-1 at room temperature attributing to the high crystallinity and surfactant-free surface, and exceptional chemical and operational stability using both solid-state dielectric and liquid-state electrical double layer. The facile ultrasonication-assisted synthesis of high-quality 2D tellurium paves the way for further exploration of E2DMs and expands the scope of liquid-phase exfoliation (LPE) methodology toward the controlled wet-chemical synthesis of functional nanomaterials.
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Affiliation(s)
- Junlei Qi
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Yongping Dai
- Department of Chemistry, Engineering Research Center of Advanced Rare Earth Materials (Ministry of Education), Tsinghua University, Beijing, 100084, China
| | - Chen Ma
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, 999077, China
| | - Chengxuan Ke
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Wenbin Wang
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Zongxiao Wu
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Xiang Wang
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Kai Bao
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Yue Xu
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Haoxin Huang
- Department of Electrical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Lingzhi Wang
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Jingkun Wu
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
| | - Guangfu Luo
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Ye Chen
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, 999077, China
| | - Zhaoyang Lin
- Department of Chemistry, Engineering Research Center of Advanced Rare Earth Materials (Ministry of Education), Tsinghua University, Beijing, 100084, China
| | - Qiyuan He
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, 999077, China
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2
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He D, Zheng Y, Ding D, Ma H, Zhang A, Cheng Y, Zhao W, Jin C. Titanium Self-Intercalation Induced Formation of Orthogonal (1 × 1) Edge/Surface Reconstruction in 1T-TiSe 2: Atomic Scale Dynamics and Mechanistic Study. NANO LETTERS 2024; 24:3835-3841. [PMID: 38498307 DOI: 10.1021/acs.nanolett.4c01040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Edges and surfaces play indispensable roles in affecting the chemical-physical properties of materials, particularly in two-dimensional transition metal dichalcogenides (TMDCs) with reduced dimensionality. Herein, we report a novel edge/surface structure in multilayer 1T-TiSe2, i.e., the orthogonal (1 × 1) reconstruction, induced by the self-intercalation of Ti atoms into interlayer octahedral sites of the host TiSe2 at elevated temperature. Formation dynamics of the reconstructed edge/surface are captured at the atomic level by in situ scanning transmission electron microscopy (STEM) and further validated by density functional theory (DFT), which enables the proposal of the nucleation mechanism and two growth routes (zigzag and armchair). Via STEM-electron energy loss spectroscopy (STEM-EELS), a chemical shift of 0.6 eV in Ti L3,2 is observed in the reconstructed edge/surface, which is attributed to the change of the coordination number and lattice distortion. The present work provides insights to tailor the atomic/electronic structures and properties of 2D TMDC materials.
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Affiliation(s)
- Daliang He
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
- Jihua Laboratory, Foshan, Guangdong 528200, China
| | - Yonghui Zheng
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Degong Ding
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
| | - Hao Ma
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266580 Shandong, China
| | - Aixinye Zhang
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266580 Shandong, China
| | - Yan Cheng
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Wen Zhao
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266580 Shandong, China
| | - Chuanhong Jin
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
- Jihua Laboratory, Foshan, Guangdong 528200, China
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3
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Li G, Zhang H, Han Y. Applications of Transmission Electron Microscopy in Phase Engineering of Nanomaterials. Chem Rev 2023; 123:10728-10749. [PMID: 37642645 DOI: 10.1021/acs.chemrev.3c00364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Phase engineering of nanomaterials (PEN) is an emerging field that aims to tailor the physicochemical properties of nanomaterials by precisely manipulating their crystal phases. To advance PEN effectively, it is vital to possess the capability of characterizing the structures and compositions of nanomaterials with precision. Transmission electron microscopy (TEM) is a versatile tool that combines reciprocal-space diffraction, real-space imaging, and spectroscopic techniques, allowing for comprehensive characterization with exceptional resolution in the domains of time, space, momentum, and, increasingly, even energy. In this Review, we first introduce the fundamental mechanisms behind various TEM-related techniques, along with their respective application scopes and limitations. Subsequently, we review notable applications of TEM in PEN research, including applications in fields such as metallic nanostructures, carbon allotropes, low-dimensional materials, and nanoporous materials. Specifically, we underscore its efficacy in phase identification, composition and chemical state analysis, in situ observations of phase evolution, as well as the challenges encountered when dealing with beam-sensitive materials. Furthermore, we discuss the potential generation of artifacts during TEM imaging, particularly in scanning modes, and propose methods to minimize their occurrence. Finally, we offer our insights into the present state and future trends of this field, discussing emerging technologies including four-dimensional scanning TEM, three-dimensional atomic-resolution imaging, and electron microscopy automation while highlighting the significance and feasibility of these advancements.
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Affiliation(s)
- Guanxing Li
- Advanced Membranes and Porous Materials Center, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Hui Zhang
- Electron Microscopy Center, South China University of Technology, Guangzhou 510640, China
- School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China
| | - Yu Han
- Advanced Membranes and Porous Materials Center, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
- Electron Microscopy Center, South China University of Technology, Guangzhou 510640, China
- School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China
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4
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Deng J, Huo D, Bai Y, Lin X, Cheng Z, Zhang C. Observations of Charge-Density-Wave States in W 6Te 6 Wires. NANO LETTERS 2023; 23:7831-7837. [PMID: 37616474 DOI: 10.1021/acs.nanolett.3c01373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Determining the electronic ground state of a one-dimensional system is crucial to understanding the underlying physics of electronic behavior. Here, we demonstrate the discovery of charge-density wave states in few-wire W6Te6 arrays using scanning tunneling microscopy/spectroscopy. We directly visualize incommensurate charge orders, energy gaps with prominent coherence peaks, and the picometer-scale lattice distortion in nearly disorder-free double-wire systems, thereby demonstrating the existence of Peierls-type charge density waves. In the presence of disorder-induced charge order fluctuations, the coherence peaks resulting from phase correlation disappear and gradually transform the system into the pseudogap states. The power-law zero-bias anomaly and quasi-particle interference analysis further suggest the Tomonaga-Luttinger liquid behavior in such pseudogap region. In addition, we explicitly determined the evolution of the CDW energy gap as a function of stacking-wire numbers. The present study demonstrates the existence of electron-phonon interactions in few-wire W6Te6 that can be tuned by disorders and van der Waals stacking.
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Affiliation(s)
- Jinghao Deng
- School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Da Huo
- School of Physics and Technology, Wuhan University, Wuhan, 430072, China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, China
| | - Yusong Bai
- School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Xiaoyu Lin
- School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Zhengbo Cheng
- School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - Chendong Zhang
- School of Physics and Technology, Wuhan University, Wuhan, 430072, China
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5
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Liu Y, Cui T, Li D. Unconventional Self-Reconstructed Trimer-like Metal Zigzag Edge of 1T-Phase Transition Metal Dichalcogenides. J Phys Chem Lett 2023; 14:3651-3657. [PMID: 37027822 DOI: 10.1021/acs.jpclett.3c00625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Undercoordination-induced slight bond contraction of the pristine edge is a conventional edge self-reconstructed pattern in two-dimensional materials that generally cannot drive the edge into its ground state. Despite reports of unconventional edge self-reconstructed patterns of 1H-phase transition metal dichalcogenides (TMDCs), there have been no reports of sister 1T-phase TMDCs. Here, we predict an unconventional (2 × 1) edge self-reconstructed pattern for 1T-TMDCs by considering 1T-TiTe2. A novel self-reconstructed trimer-like metal zigzag edge (TMZ edge) with one-dimensional metal atomic chains and Ti3 trimers is uncovered. Its metal triatomic 3d orbital coupling leads to Ti3 trimerization. This TMZ edge occurs in group IV, V, and X 1T-TMDCs and has an energetic advantage far beyond conventional bond contraction. The unique triatomic synergistic effect results in better catalysis of the hydrogen evolution reaction (HER) for the 1T-TMDCs than with commercial platinum-based catalysts. This study provides a new strategy for maximizing the HER catalytic efficiency of 1T-TMDCs by using atomic edge engineering.
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Affiliation(s)
- Yue Liu
- State Key Lab of Superhard Materials, College of Physics, Jilin University, Changchun 130012, P. R. China
| | - Tian Cui
- State Key Lab of Superhard Materials, College of Physics, Jilin University, Changchun 130012, P. R. China
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, P. R. China
| | - Da Li
- State Key Lab of Superhard Materials, College of Physics, Jilin University, Changchun 130012, P. R. China
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6
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Natsui R, Shimizu H, Nakanishi Y, Liu Z, Shimamura A, Hung NT, Lin YC, Endo T, Pu J, Kikuchi I, Takenobu T, Okada S, Suenaga K, Saito R, Miyata Y. Vapor-Phase Indium Intercalation in van der Waals Nanofibers of Atomically Thin W 6Te 6 Wires. ACS NANO 2023; 17:5561-5569. [PMID: 36820647 DOI: 10.1021/acsnano.2c10997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
One-dimensional (1D) conducting materials are of great interest as potential building blocks for integrated nanocircuits. Ternary 1D transition-metal chalcogenides, consisting of M6X6 wires with intercalated A atoms (M = Mo or W; X = S, Se, or Te; A = alkali or rare metals, etc.), have attracted much attention due to their 1D metallic behavior, superconductivity, and mechanical flexibility. However, the conventional solid-state reaction usually produces micrometer-scale bulk crystals, limiting their potential use as nanoscale conductors. Here we demonstrate a versatile method to fabricate indium (In)-intercalated W6Te6 (In-W6Te6) bundles with a nanoscale thickness. We first prepared micrometer-long, crystalline bundles of van der Waals W6Te6 wires using chemical vapor deposition and intercalated In into the crystal via a vapor-phase reaction. Atomic-resolution electron microscopy revealed that In atoms were surrounded by three adjacent W6Te6 wires. First-principles calculations suggested that their wire-by-wire stacking can transform through postgrowth intercalation. Individual In-W6Te6 bundles exhibited metallic behavior, as theoretically predicted. We further identified the vibrational modes by combining polarized Raman spectroscopy and nonresonant Raman calculations.
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Affiliation(s)
- Ryusuke Natsui
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Hiroshi Shimizu
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Yusuke Nakanishi
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Zheng Liu
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Nagoya 463-8560, Japan
| | - Akito Shimamura
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Nguyen Tuan Hung
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Yung-Chang Lin
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
| | - Takahiko Endo
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
| | - Jiang Pu
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
| | - Iori Kikuchi
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
| | - Taishi Takenobu
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
| | - Susumu Okada
- Department of Physics, University of Tsukuba, Tsukuba 305-8571, Japan
| | - Kazu Suenaga
- The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan
| | - Riichiro Saito
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - Yasumitsu Miyata
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
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7
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Giri A, Park G, Jeong U. Layer-Structured Anisotropic Metal Chalcogenides: Recent Advances in Synthesis, Modulation, and Applications. Chem Rev 2023; 123:3329-3442. [PMID: 36719999 PMCID: PMC10103142 DOI: 10.1021/acs.chemrev.2c00455] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The unique electronic and catalytic properties emerging from low symmetry anisotropic (1D and 2D) metal chalcogenides (MCs) have generated tremendous interest for use in next generation electronics, optoelectronics, electrochemical energy storage devices, and chemical sensing devices. Despite many proof-of-concept demonstrations so far, the full potential of anisotropic chalcogenides has yet to be investigated. This article provides a comprehensive overview of the recent progress made in the synthesis, mechanistic understanding, property modulation strategies, and applications of the anisotropic chalcogenides. It begins with an introduction to the basic crystal structures, and then the unique physical and chemical properties of 1D and 2D MCs. Controlled synthetic routes for anisotropic MC crystals are summarized with example advances in the solution-phase synthesis, vapor-phase synthesis, and exfoliation. Several important approaches to modulate dimensions, phases, compositions, defects, and heterostructures of anisotropic MCs are discussed. Recent significant advances in applications are highlighted for electronics, optoelectronic devices, catalysts, batteries, supercapacitors, sensing platforms, and thermoelectric devices. The article ends with prospects for future opportunities and challenges to be addressed in the academic research and practical engineering of anisotropic MCs.
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Affiliation(s)
- Anupam Giri
- Department of Chemistry, Faculty of Science, University of Allahabad, Prayagraj, UP-211002, India
| | - Gyeongbae Park
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Cheongam-Ro 77, Nam-Gu, Pohang, Gyeongbuk790-784, Korea.,Functional Materials and Components R&D Group, Korea Institute of Industrial Technology, Gwahakdanji-ro 137-41, Sacheon-myeon, Gangneung, Gangwon-do25440, Republic of Korea
| | - Unyong Jeong
- Department of Materials Science and Engineering, Pohang University of Science and Technology, Cheongam-Ro 77, Nam-Gu, Pohang, Gyeongbuk790-784, Korea
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8
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Lee CH, Ryu H, Nolan G, Zhang Y, Lee Y, Oh S, Cheong H, Watanabe K, Taniguchi T, Kim K, Lee GH, Huang PY. In Situ Imaging of an Anisotropic Layer-by-Layer Phase Transition in Few-Layer MoTe 2. NANO LETTERS 2023; 23:677-684. [PMID: 36648125 DOI: 10.1021/acs.nanolett.2c04550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Understanding the phase transition mechanisms in two-dimensional (2D) materials is a key to precisely tailor their properties at the nanoscale. Molybdenum ditelluride (MoTe2) exhibits multiple phases at room temperature, making it a promising candidate for phase-change applications. Here, we fabricate lateral 2H-Td interfaces with laser irradiation and probe their phase transitions from micro- to atomic scales with in situ heating in the transmission electron microscope (TEM). By encapsulating the MoTe2 with graphene protection layers, we create an in situ reaction cell compatible with atomic resolution imaging. We find that the Td-to-2H phase transition initiates at phase boundaries at low temperatures (200-225 °C) and propagates anisotropically along the b-axis in a layer-by-layer fashion. We also demonstrate a fully reversible 2H-Td-2H phase transition cycle, which generates a coherent 2H lattice containing inversion domain boundaries. Our results provide insights on fabricating 2D heterophase devices with atomically sharp and coherent interfaces.
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Affiliation(s)
- Chia-Hao Lee
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
| | - Huije Ryu
- Department of Materials Science and Engineering, Seoul National University, Seoul08826, Korea
| | - Gillian Nolan
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
| | - Yichao Zhang
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
| | - Yangjin Lee
- Department of Physics, Yonsei University, Seoul03722, Korea
| | - Siwon Oh
- Department of Physics, Sogang University, Seoul04107, Korea
| | | | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba305-0044, Japan
| | - Kwanpyo Kim
- Department of Physics, Yonsei University, Seoul03722, Korea
| | - Gwan-Hyoung Lee
- Department of Materials Science and Engineering, Seoul National University, Seoul08826, Korea
| | - Pinshane Y Huang
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois61801, United States
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9
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Lasek K, Li J, Ghorbani-Asl M, Khatun S, Alanwoko O, Pathirage V, Krasheninnikov AV, Batzill M. Formation of In-Plane Semiconductor-Metal Contacts in 2D Platinum Telluride by Converting PtTe 2 to Pt 2Te 2. NANO LETTERS 2022; 22:9571-9577. [PMID: 36399113 DOI: 10.1021/acs.nanolett.2c03715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Monolayer PtTe2 is a narrow gap semiconductor while Pt2Te2 is a metal. Here we show that the former can be transformed into the latter by reaction with vapor-deposited Pt atoms. The transformation occurs by nucleating the Pt2Te2 phase within PtTe2 islands, so that a metal-semiconductor junction is formed. A flat band structure is found with the Fermi level of the metal aligning with that of the intrinsically p-doped PtTe2. This is achieved by an interface dipole that accommodates the ∼0.2 eV shift in the work functions of the two materials. First-principles calculations indicate that the origin of the interface dipole is the atomic scale charge redistributions at the heterojunction. The demonstrated compositional phase transformation of a 2D semiconductor into a 2D metal is a promising approach for making in-plane metal contacts that are required for efficient charge injection and is of particular interest for semiconductors with large spin-orbit coupling, like PtTe2.
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Affiliation(s)
- Kinga Lasek
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Jingfeng Li
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Mahdi Ghorbani-Asl
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Salma Khatun
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Onyedikachi Alanwoko
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Vimukthi Pathirage
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Arkady V Krasheninnikov
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Department of Applied Physics, Aalto University, P.O. Box 11100, 00076 Aalto, Finland
| | - Matthias Batzill
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
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10
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Ripoll-Sau J, Calleja F, Casado Aguilar P, Ibarburu IM, Vázquez de Parga AL, Miranda R, Garnica M. Phase control and lateral heterostructures of MoTe 2 epitaxially grown on graphene/Ir(111). NANOSCALE 2022; 14:10880-10888. [PMID: 35848284 DOI: 10.1039/d2nr03074h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Engineering the growth of the different phases of two-dimensional transition metal dichalcogenides (2D-TMDs) is a promising way to exploit their potential since the phase determines their physical and chemical properties. Here, we report on the epitaxial growth of monolayer MoTe2 on graphene on an Ir(111) substrate. Scanning tunneling microscopy and spectroscopy provide insights into the structural and electronic properties of the different polymorphic phases, which remain decoupled from the substrate due to the weak interaction with graphene. In addition, we demonstrate a great control of the relative coverage of the relevant 1T' and 1H MoTe2 phases by varying the substrate temperature during the growth. In particular, we obtain large areas of the 1T' phase exclusively or the coexistence of both phases with different ratios.
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Affiliation(s)
- Joan Ripoll-Sau
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain.
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Fabian Calleja
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain.
| | - Pablo Casado Aguilar
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain.
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Iván M Ibarburu
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain.
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Amadeo L Vázquez de Parga
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain.
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto "Nicolás Cabrera", Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Rodolfo Miranda
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain.
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto "Nicolás Cabrera", Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Manuela Garnica
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain.
- Instituto "Nicolás Cabrera", Universidad Autónoma de Madrid, 28049 Madrid, Spain
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11
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Lasek K, Ghorbani-Asl M, Pathirage V, Krasheninnikov AV, Batzill M. Controlling Stoichiometry in Ultrathin van der Waals Films: PtTe 2, Pt 2Te 3, Pt 3Te 4, and Pt 2Te 2. ACS NANO 2022; 16:9908-9919. [PMID: 35652695 DOI: 10.1021/acsnano.2c04303] [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
The platinum-tellurium phase diagram exhibits various (meta)stable van der Waals (vdW) materials that can be constructed by stacking PtTe2 and Pt2Te2 layers. Monophase PtTe2, being the thermodynamically most stable compound, can readily be grown as thin films. Obtaining the other phases (Pt2Te3, Pt3Te4, Pt2Te2), especially in their ultimate thin form, is significantly more challenging. We show that PtTe2 thin films can be transformed by vacuum annealing-induced Te-loss into Pt3Te4- and Pt2Te2-bilayers. These transformations are characterized by scanning tunneling microscopy and X-ray and angle resolved photoemission spectroscopy. Once Pt3Te4 is formed, it is thermally stable up to 350°C. To transform Pt3Te4 into Pt2Te2, a higher annealing temperature of 400°C is required. The experiments combined with density functional theory calculations provide insights into these transformation mechanisms and show that a combination of the thermodynamic preference of Pt3Te4 over a phase segregation into PtTe2 and Pt2Te2 and an increase in the Te-vacancy formation energy for Pt3Te4 compared to the starting PtTe2 material is critical to stabilize the Pt3Te4 bilayer. To desorb more tellurium from Pt3Te4 and transform the material into Pt2Te2, a higher Te-vacancy formation energy has to be overcome by raising the temperature. Interestingly, bilayer Pt2Te2 can be retellurized by exposure to Te-vapor. This causes the selective transformation of the topmost Pt2Te2 layer into two layers of PtTe2, and consequently the synthesis of e Pt2Te3. Thus, all known Pt-telluride vdW compounds can be obtained in their ultrathin form by carefully controlling the stoichiometry of the material.
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Affiliation(s)
- Kinga Lasek
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Mahdi Ghorbani-Asl
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - Vimukthi Pathirage
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Arkady V Krasheninnikov
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
- Department of Applied Physics, Aalto University, P.O. Box 11100, 00076 Aalto, Finland
| | - Matthias Batzill
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
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12
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Wang P, Yang Y, Pan E, Liu F, Ajayan PM, Zhou J, Liu Z. Emerging Phases of Layered Metal Chalcogenides. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2105215. [PMID: 34923740 DOI: 10.1002/smll.202105215] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 11/10/2021] [Indexed: 06/14/2023]
Abstract
Layered metal chalcogenides, as a "rich" family of 2D materials, have attracted increasing research interest due to the abundant choices of materials with diverse structures and rich electronic characteristics. Although the common metal chalcogenide phases such as 2H and 1T have been intensively studied, many other unusual phases are rarely explored, and some of these show fascinating behaviors including superconductivity, ferroelectrics, ferromagnetism, etc. From this perspective, the unusual phases of metal chalcogenides and their characteristics, as well as potential applications are introduced. First, the unusual phases of metal chalcogenides from different classes, including transition metal dichalcogenides, magnetic element-based chalcogenides, and metal phosphorus chalcogenides, are discussed, respectively. Meanwhile, their excellent properties of different unusual phases are introduced. Then, the methods for producing the unusual phases are discussed, specifically, the stabilization strategies during the chemical vapor deposition process for the unusual phase growth are discussed, followed by an outlook and discussions on how to prepare the unusual phase metal dichalcogenides in terms of synthetic methodology and potential applications.
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Affiliation(s)
- Ping Wang
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics, and Ultrafine Optoelectronic Systems, and School of Physics, School of Physics, Beijing Institute of Technology, Beijing, 100081, China
| | - Yang Yang
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics, and Ultrafine Optoelectronic Systems, and School of Physics, School of Physics, Beijing Institute of Technology, Beijing, 100081, China
| | - Er Pan
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, 313099, China
| | - Fucai Liu
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, 313099, China
| | - Pulickel M Ajayan
- Department of Materials Science and Nano Engineering, Rice University, Houston, TX, 77005, USA
| | - Jiadong Zhou
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics, and Ultrafine Optoelectronic Systems, and School of Physics, School of Physics, Beijing Institute of Technology, Beijing, 100081, China
| | - Zheng Liu
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
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13
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Ko W, Gai Z, Puretzky AA, Liang L, Berlijn T, Hachtel JA, Xiao K, Ganesh P, Yoon M, Li AP. Understanding Heterogeneities in Quantum Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022:e2106909. [PMID: 35170112 DOI: 10.1002/adma.202106909] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 02/08/2022] [Indexed: 06/14/2023]
Abstract
Quantum materials are usually heterogeneous, with structural defects, impurities, surfaces, edges, interfaces, and disorder. These heterogeneities are sometimes viewed as liabilities within conventional systems; however, their electronic and magnetic structures often define and affect the quantum phenomena such as coherence, interaction, entanglement, and topological effects in the host system. Therefore, a critical need is to understand the roles of heterogeneities in order to endow materials with new quantum functions for energy and quantum information science applications. In this article, several representative examples are reviewed on the recent progress in connecting the heterogeneities to the quantum behaviors of real materials. Specifically, three intertwined topic areas are assessed: i) Reveal the structural, electronic, magnetic, vibrational, and optical degrees of freedom of heterogeneities. ii) Understand the effect of heterogeneities on the behaviors of quantum states in host material systems. iii) Control heterogeneities for new quantum functions. This progress is achieved by establishing the atomistic-level structure-property relationships associated with heterogeneities in quantum materials. The understanding of the interactions between electronic, magnetic, photonic, and vibrational states of heterogeneities enables the design of new quantum materials, including topological matter and quantum light emitters based on heterogenous 2D materials.
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Affiliation(s)
- Wonhee Ko
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Zheng Gai
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Alexander A Puretzky
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Liangbo Liang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Tom Berlijn
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Jordan A Hachtel
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Kai Xiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Panchapakesan Ganesh
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - Mina Yoon
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
| | - An-Ping Li
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA
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14
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Ortiz-Rodríguez JC, Perryman JT, Velázquez JM. Charge Transport Dynamics in Microwave Synthesized One-Dimensional Molybdenum Chalcogenides. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c02825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jessica C. Ortiz-Rodríguez
- Department of Chemistry, University of California Davis, One Shields Avenue, Davis, California 95616, United States
| | - Joseph T. Perryman
- Department of Chemistry, University of California Davis, One Shields Avenue, Davis, California 95616, United States
| | - Jesús M. Velázquez
- Department of Chemistry, University of California Davis, One Shields Avenue, Davis, California 95616, United States
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15
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Wu JF, Ke SS, Guo Y, Zhang HW, Lü HF. Noncentrosymmetric Weyl phase and topological phase transition in bulk MoTe. Phys Chem Chem Phys 2021; 23:23196-23202. [PMID: 34622258 DOI: 10.1039/d1cp02793j] [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
Ideal topological materials are those stable materials with less nontrivial band crossing near the Fermi surface and a long Fermi arc. By means of first-principles calculations, here we present that the 3D monochalcogenide molybdenum telluride (Pm-MoTe) without an inversion center shows a type-II Weyl semimetal (WSM) phase which cannot checked by symmetry index method. A total of eight Weyl points (WPs) are found in different quadrants of the Brillouin zone (BZ) of Pm-MoTe, which guarantee a long Fermi arc. The WSM phase is robust against the spin-orbit coupling (SOC) effect because of mirror symmetry and time reversal symmetry. It is also found that a topological phase transition can be tuned by strain. For different types of strain, the number of WPs can be effectively modulated to a minimum number, and their energies could be closer to Fermi level. These findings propose a promising material candidate that partly satisfies the ideal WSM criteria and extends the potential applications of the tunable topological phase.
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Affiliation(s)
- Jia-Fang Wu
- School of Physics and State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China.
| | - Sha-Sha Ke
- School of Physics and State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China.
| | - Yong Guo
- Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
| | - Huai-Wu Zhang
- School of Physics and State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China.
| | - Hai-Feng Lü
- School of Physics and State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. .,Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
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16
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Study on the electronic properties of M6X6 (M = Mo, W; X = S, Se, Te) nanowire arrays. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Ji X, Ding D, Guan X, Wu C, Qian H, Cao J, Li J, Jin C. Interlayer Coupling Dependent Discrete H → T' Phase Transition in Lithium Intercalated Bilayer Molybdenum Disulfide. ACS NANO 2021; 15:15039-15046. [PMID: 34495636 DOI: 10.1021/acsnano.1c05332] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this work, the interlayer coupling dependent lithium intercalation induced phase transition in bilayer MoS2 (BL-MoS2) was investigated using an atomic-resolution annual dark-field scanning transmission electron microscope (ADF-STEM). It was revealed that the lithiation induced H → T' phase transition in BL-MoS2 strongly depended on the interlayer twist angle; i.e., the H → T' phase transition occurred in well-stacked H phase BL-MoS2 (with a twist angle of θt = 0°) but not for θt ≠ 0° BL-MoS2. The lithiated BL-MoS2 appeared in homophase stacking, either T'/T' or H/H (locally, no phase transformation) stacking, without any heterophase stacking such as H/T' or T'/H observed. This finding indicated the H → T' phase transition occurred via a domain-by-domain mode rather than layer-by-layer. Up to 15 types of stacking orders were experimentally identified locally in lithiated bilayer T'-MoS2, and the formation mechanism was attributed to the discrete interlayer translation with a unit step of (m/6a, n/6b) (m, n = 0, 1, 2, 3), where a and b were the primitive lattice vectors of T'-MoS2. Our experimental results were further corroborated by ab initio density functional theory (DFT) calculations, where the occurrence of different stacking orders can be quantitatively correlated with the variation of intercalated lithium contents into the BL-MoS2. The present study aids in the understanding of the phase transition mechanisms in atomically thin 2D transition metal dichalcogenides (TMDCs) and will also shed light on the precisely controlled phase engineering of 2D materials for memory applications.
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Affiliation(s)
- Xujing Ji
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Degong Ding
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Xiaoxiao Guan
- Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University, Xiangtan, Hunan 411105, China
| | - Chunyang Wu
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Haofu Qian
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Juexian Cao
- Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University, Xiangtan, Hunan 411105, China
| | - Jixue Li
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Chuanhong Jin
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
- Jihua Laboratory, Foshan, Guangdong 528200, China
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18
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Huang PY, Qin JK, Zhu CY, Zhen L, Xu CY. 2D-1D mixed-dimensional heterostructures: progress, device applications and perspectives. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:493001. [PMID: 34479213 DOI: 10.1088/1361-648x/ac2388] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Two-dimensional (2D) materials have attracted broad interests and been extensively exploited for a variety of functional applications. Moreover, one-dimensional (1D) atomic crystals can also be integrated into 2D templates to create mixed-dimensional heterostructures, and the versatility of combinations provides 2D-1D heterostructures plenty of intriguing physical properties, making them promising candidate to construct novel electronic and optoelectronic nanodevices. In this review, we first briefly present an introduction of relevant fabrication methods and structural configurations for 2D-1D heterostructures integration. We then discuss the emerged intriguing physics, including high optical absorption, efficient carrier separation, fast charge transfer and plasmon-exciton interconversion. Their potential applications such as electronic/optoelectronic devices, photonic devices, spintronic devices and gas sensors, are also discussed. Finally, we provide a brief perspective for the future opportunities and challenges in this emerging field.
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Affiliation(s)
- Pei-Yu Huang
- Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, People's Republic of China
| | - Jing-Kai Qin
- Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, People's Republic of China
| | - Cheng-Yi Zhu
- Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, People's Republic of China
| | - Liang Zhen
- Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, People's Republic of China
- MOE Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Harbin Institute of Technology, Harbin 150080, People's Republic of China
- School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, People's Republic of China
| | - Cheng-Yan Xu
- Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, People's Republic of China
- MOE Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Harbin Institute of Technology, Harbin 150080, People's Republic of China
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19
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Peng Y, Wei X, Jin C, Zhang Y, Cao J. Strain induced structural phase transition in TM6X6 (TM = Mo, W; X = S, Se, Te) nanowires. J SOLID STATE CHEM 2021. [DOI: 10.1016/j.jssc.2021.122194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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20
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Shang C, Fu L, Zhou S, Zhao J. Atomic Wires of Transition Metal Chalcogenides: A Family of 1D Materials for Flexible Electronics and Spintronics. JACS AU 2021; 1:147-155. [PMID: 34467280 PMCID: PMC8395661 DOI: 10.1021/jacsau.0c00049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Indexed: 05/21/2023]
Abstract
As analogues of two-dimensional (2D) layered materials, searching for one-dimensional (1D) van der Waals wired materials as 1D Lego blocks for integration and device applications has been pursued. Motivated by the recently synthesized atomic wires of molybdenum chalcogenide, here we explored the structures and stability of 66 atomic wires of 3d, 4d, and 5d transition metal chalcogenides in the M6X6 stoichiometry (M = transition metal, X = chalcogen). After high-throughput first-principles calculations, 53 unprecedented and experimentally feasible M6X6 wires have been identified. Diverse functionalities are found in these 1D materials, including semiconductors, metals, and ferromagnets with high Young's modulus and large fracture strain. Notably, six kinds of M6X6 wires are robust ferromagnets with Curie temperatures up to 700 K, which can be further elevated under axial strains. Moreover, these M6X6 atomic wires possess high stability and resistance to oxidation, humidity, and aggregation; both merits are desirable for device applications. This large family of 1D materials with definite structures and rich properties allows atomically precise integration for flexible electronics and spintronics.
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21
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Zhao X, Loh KP, Pennycook SJ. Electron beam triggered single-atom dynamics in two-dimensional materials. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:063001. [PMID: 33007771 DOI: 10.1088/1361-648x/abbdb9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Controlling atomic structure and dynamics with single-atom precision is the ultimate goal in nanoscience and nanotechnology. Despite great successes being achieved by scanning tunneling microscopy (STM) over the past a few decades, fundamental limitations, such as ultralow temperature, and low throughput, significantly hinder the fabrication of a large array of atomically defined structures by STM. The advent of aberration correction in scanning transmission electron microscopy (STEM) revolutionized the field of nanomaterials characterization pushing the detection limit down to single-atom sensitivity. The sub-angstrom focused electron beam (e-beam) of STEM is capable of interacting with an individual atom, thereby it is the ideal platform to direct and control matter at the level of a single atom or a small cluster. In this article, we discuss the transfer of energy and momentum from the incident e-beam to atoms and their subsequent potential dynamics under different e-beam conditions in 2D materials, particularly transition metal dichalcogenides (TMDs). Next, we systematically discuss the e-beam triggered structural evolutions of atomic defects, line defects, grain boundaries, and stacking faults in a few representative 2D materials. Their formation mechanisms, kinetic paths, and practical applications are comprehensively discussed. We show that desired structural evolution or atom-by-atom assembly can be precisely manipulated by e-beam irradiation which could introduce intriguing functionalities to 2D materials. In particular, we highlight the recent progress on controlling single Si atom migration in real-time on monolayer graphene along an extended path with high throughput in automated STEM. These results unprecedentedly demonstrate that single-atom dynamics can be realized by an atomically focused e-beam. With the burgeoning of artificial intelligence and big data, we can expect that fully automated microscopes with real-time data analysis and feedback could readily design and fabricate large scale nanostructures with unique functionalities in the near future.
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Affiliation(s)
- Xiaoxu Zhao
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
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22
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Lim HE, Nakanishi Y, Liu Z, Pu J, Maruyama M, Endo T, Ando C, Shimizu H, Yanagi K, Okada S, Takenobu T, Miyata Y. Wafer-Scale Growth of One-Dimensional Transition-Metal Telluride Nanowires. NANO LETTERS 2021; 21:243-249. [PMID: 33307702 DOI: 10.1021/acs.nanolett.0c03456] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The development of bulk synthetic processes to prepare functional nanomaterials is crucial to achieve progress in fundamental and applied science. Transition-metal chalcogenide (TMC) nanowires, which are one-dimensional (1D) structures having three-atom diameters and van der Waals surfaces, have been reported to possess a 1D metallic nature with great potential in electronics and energy devices. However, their mass production remains challenging. Here, a wafer-scale synthesis of highly crystalline transition-metal telluride nanowires is demonstrated by chemical vapor deposition. The present technique enables formation of either aligned, atomically thin two-dimensional (2D) sheets or random networks of three-dimensional (3D) bundles, both composed of individual nanowires. These nanowires exhibit an anisotropic 1D optical response and superior conducting properties. The findings not only shed light on the controlled and large-scale synthesis of conductive thin films but also provide a platform for the study on physics and device applications of nanowire-based 2D and 3D crystals.
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Affiliation(s)
- Hong En Lim
- Department of Physics, Tokyo Metropolitan University, Hachioji 192-0397, Japan
| | - Yusuke Nakanishi
- Department of Physics, Tokyo Metropolitan University, Hachioji 192-0397, Japan
| | - Zheng Liu
- Innovative Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Nagoya 463-8560, Japan
| | - Jiang Pu
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
| | - Mina Maruyama
- Department of Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan
| | - Takahiko Endo
- Department of Physics, Tokyo Metropolitan University, Hachioji 192-0397, Japan
| | - Chisato Ando
- Department of Physics, Tokyo Metropolitan University, Hachioji 192-0397, Japan
| | - Hiroshi Shimizu
- Department of Physics, Tokyo Metropolitan University, Hachioji 192-0397, Japan
| | - Kazuhiro Yanagi
- Department of Physics, Tokyo Metropolitan University, Hachioji 192-0397, Japan
| | - Susumu Okada
- Department of Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan
| | - Taishi Takenobu
- Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan
| | - Yasumitsu Miyata
- Department of Physics, Tokyo Metropolitan University, Hachioji 192-0397, Japan
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23
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Deng J, Huo D, Bai Y, Guo Y, Pan Z, Lu S, Cui P, Zhang Z, Zhang C. Precise Tuning of Band Structures and Electron Correlations by van der Waals Stacking of One-dimensional W 6Te 6 Wires. NANO LETTERS 2020; 20:8866-8873. [PMID: 33227207 DOI: 10.1021/acs.nanolett.0c03897] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Stacking of two-dimensional (2D) van der Waals (vdW) atomic sheets has been established as a powerful approach to fabricating new materials with broad versatilities and emergent functionalities. Here we demonstrate a bottom-up approach to fabricating isolated single W6Te6 wires and their lateral assemblies, offering a unique platform for investigating the elegant role of vdW coupling in 1D systems with atomic precision. We find experimentally and theoretically a single W6Te6 wire is a 1D semiconductor with a band gap of ∼60 meV, and a semiconductor-to-metal transition takes place upon interwire vdW stacking. The metallic multiwires exhibit strong Tomonaga-Luttinger liquid characteristics with the correlation parameter g varying from g = 0.086 for biwire to g = 0.136 for six-wire assemblies, all much reduced from the Fermi liquid regime (g = 1). The present study demonstrates wire-by-wire vdW stacking is a versatile means for fabrication of 1D systems with tunable electronic properties.
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Affiliation(s)
- Jinghao Deng
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Da Huo
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Yusong Bai
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Yanping Guo
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Zemin Pan
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Shuangzan Lu
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Ping Cui
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at Microscale (HFNL), and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhenyu Zhang
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at Microscale (HFNL), and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Chendong Zhang
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
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24
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Lu Z, Liang D, Ping X, Xing L, Wang Z, Wu L, Lu P, Jiao L. 1D/2D Heterostructures as Ultrathin Catalysts for Hydrogen Evolution Reaction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2004296. [PMID: 33052002 DOI: 10.1002/smll.202004296] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/22/2020] [Indexed: 06/11/2023]
Abstract
2D MoS2 has emerged as a promising alternative to Pt-based catalysts for hydrogen evolution reaction (HER) due to its low cost and earth abundance. However, insufficient active sites of basal plane and poor conductivity become the foremost factors restricting the catalytic performance of MoS2 . Here, a facile strategy is presented to enhance the HER performance of MoS2 by converting its 2D structure into 1D/2D heterostructures of Mo6 Te6 /MoS2(1- x ) Te2 x by the in situ tellurization. As-prepared 1D/2D heterostructures exhibit excellent HER performance with the Tafel slope of ≈56 mV dec-1 (only one-third of that for pristine MoS2 ). The enhanced HER catalytic activity is attributed to more Te/S vacancies introduced by tellurization, which serve as the active sites as suggested by theoretical calculations. Besides, the formation of highly conductive well-aligned quasi-1D Mo6 Te6 nanobelts facilitate charge transport in HER. Previous work provides a facile approach to construct mixed dimensional materials, and opens up a new avenue to the properties modulation of 2D transition metal chalcogenides.
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Affiliation(s)
- Zhixing Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, iChEM, Xiamen University, Xiamen, 361005, China
- Department Key Lab of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Dan Liang
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, 100876, China
| | - Xiaofan Ping
- Department Key Lab of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Lei Xing
- Department Key Lab of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Zechao Wang
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Liyuan Wu
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, 100876, China
| | - Pengfei Lu
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, 100876, China
| | - Liying Jiao
- Department Key Lab of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, China
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25
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Kim H, Johns JE, Yoo Y. Mixed-Dimensional In-Plane Heterostructures from 1D Mo 6 Te 6 and 2D MoTe 2 Synthesized by Te-Flux-Controlled Chemical Vapor Deposition. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2002849. [PMID: 33103352 DOI: 10.1002/smll.202002849] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/04/2020] [Indexed: 06/11/2023]
Abstract
Mixed-dimensional van der Waals heterostructures are scientifically important and practically useful because of their interesting exotic properties resulting from their novel hybrid structures. This study reports the composition- and phase-selective fabrication of low-dimensional molybdenum/tellurium (Mo/Te) compounds and the direct synthesis of mixed-dimensional in-plane 1D-2D Mo6 Te6 -MoTe2 heterostructures. The composition and phase of the Mo/Te compounds are controlled by changing the Te atomic flux that is adjusted by the Te temperature. Metallic 1D Mo6 Te6 wires with an intrinsic 1D structure with a diameter of 3-8 nm and length of 100-300 nm are synthesized to form wire networks under low Te flux conditions, whereas the semiconducting few-layer 2H MoTe2 films preferentially oriented along the <0001> direction are obtained under high Te flux. Under medium Te flux, the mixed-dimensional in-plane 1D-2D Mo6 Te6 -MoTe2 heterostructures are synthesized in which the semiconducting few-layer 2H MoTe2 circular domains are edge-contacted by the metallic 1D Mo6 Te6 wire networks. Furthermore, the present Te-flux-controlled method reveals that the 1D Mo6 Te6 networks change to few-layer MoTe2 films as the Te flux increases. The in-plane 1D-2D Mo6 Te6 -MoTe2 heterostructures synthesized by this method can be considered as advanced edge-contacted 2D semiconductors for high-performance 2D electronics.
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Affiliation(s)
- Hyeonkyeong Kim
- Department of Chemistry, Ajou University, Suwon, 16499, Korea
- Department of Energy Systems Research, Ajou University, Suwon, 16499, Korea
| | - James E Johns
- Department of Chemistry, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Youngdong Yoo
- Department of Chemistry, Ajou University, Suwon, 16499, Korea
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26
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Kanda N, Nakanishi Y, Liu D, Liu Z, Inoue T, Miyata Y, Tománek D, Shinohara H. Efficient growth and characterization of one-dimensional transition metal tellurides inside carbon nanotubes. NANOSCALE 2020; 12:17185-17190. [PMID: 32492076 DOI: 10.1039/d0nr03129a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Atomically thin one-dimensional (1D) van der Waals wires of transition metal monochalocogenides (TMMs) have been anticipated as promising building blocks for integrated nanoelectronics. While reliable production of TMM nanowires has eluded scientists over the past few decades, we finally demonstrated a bottom-up fabrication of MoTe nanowires inside carbon nanotubes (CNTs). Still, the current synthesis method is based on vacuum annealing of reactive MoTe2, and limits access to a variety of TMMs. Here we report an expanded framework for high-yield synthesis of the 1D tellurides including WTe, an previously unknown family of TMMs. Experimental and theoretical analyses revealed that the choice of suitable metal oxides as a precursor provides a useful yield for their characterization. These TMM nanowires exhibit a significant optical absorption in the visible-light region. More important, electronic properties of CNTs can be tuned by encapsulating different TMM nanowires.
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Affiliation(s)
- Naoyuki Kanda
- Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan.
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27
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Jin KH, Liu F. 1D topological phases in transition-metal monochalcogenide nanowires. NANOSCALE 2020; 12:14661-14667. [PMID: 32614026 DOI: 10.1039/d0nr03529g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The Su-Schrieffer-Heeger (SSH) model is a prototypical one-dimensional (1D) diatomic lattice model for non-trivial topological phases and topological excitations. Theoretically, many variations and extensions of the SSH model have been proposed and explored to better understand the novel aspects of topological physics in low dimensions on the nanoscale. However, the outstanding challenge remains to find real nanomaterials with robust structural stability for realizing the 1D topological states. Here, we develop an extended version of the SSH model with multi-atomic bases of four, six and eight atoms and an imposed screw rotation symmetry. Furthermore, based on first-principles calculations, we demonstrate the realization of this model in transition metal monochalcogenide M6X6 (M = Mo and W; X = S, Se and Te) nanowires. The topological features of the doped M6X6 nanowires are confirmed with non-trivial edge modes and e/2 fractional charges, representative of the 1D non-trivial Zak phase. Our finding not only sheds new light on our fundamental understanding of 1D topological physics, but also significantly extends the scope of 1D topological materials that will attract immediate experimental interest, since isolated M6X6 nanowires have already been synthesized in experiments.
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Affiliation(s)
- Kyung-Hwan Jin
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea and Department of Physics, Pohang University of Science and Technology, Pohang 37673, Republic of Korea and Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112, USA.
| | - Feng Liu
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112, USA.
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28
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Zhang W, Wang J, Zhao L, Wang J, Zhao M. Transition-metal monochalcogenide nanowires: highly efficient bi-functional catalysts for the oxygen evolution/reduction reactions. NANOSCALE 2020; 12:12883-12890. [PMID: 32520041 DOI: 10.1039/d0nr01148g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Stable bi-functional electrocatalysts for the oxygen evolution/reduction reactions (OER/ORR) are desirable for rechargeable metal-air batteries and regenerative fuel cell technologies. In this study, the electronic structures and catalytic performance of recently synthesized transition-metal monochalcogenide (MX, M = Cr, Mo, W; X = S, Se, Te) nanowires (NWs) were systemically investigated based on first-principles calculations. The results demonstrate that these MX NWs can be deemed as efficient bi-functional catalysts for the OER/ORR. In particular, the low overpotentials of CrTe NWs are even superior to those of the well-known noble catalysts. To study the origin of excellent electrocatalytic performance, we establish linear relationships between the adsorption strength of intermediates and the overpotentials. A comparison study reveals that the NWs exhibit better catalytic performance than the corresponding two-dimensional materials, indicating the superiority of the unique NW structures for catalysis. These computational results offer not only a new family of bi-functional OER/ORR catalysts, but also a promising perspective for the development of stable, low-cost and highly active non-noble electrocatalysts.
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Affiliation(s)
- Wenqing Zhang
- School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, China.
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29
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Zhu H, Addou R, Wang Q, Nie Y, Cho K, Kim MJ, Wallace RM. Surface and interfacial study of atomic layer deposited Al 2O 3 on MoTe 2 and WTe 2. NANOTECHNOLOGY 2020; 31:055704. [PMID: 31618710 DOI: 10.1088/1361-6528/ab4e44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The atomic layer deposition (ALD) of high-k dielectrics could build an efficient barrier against moisture and O2 adsorption. Such a barrier is highly needed for MoTe2 and WTe2 transition metal dichalcogenides because of the poor structural stability and the fast oxidization in ambient air. In situ x-ray photoelectron spectroscopy and ex situ atomic force microscopy and scanning transmission electron microscopy were employed to report a comparative study between the growth of Al2O3 on MoTe2 and WTe2 by means of traditional thermal ALD and plasma-enhanced ALD (PEALD). Similar to what has been observed on other 2D materials such as MoS2 and Graphene, the thermal ALD results in an islanding growth of Al2O3 on MoTe2 due to the dearth of dangling bonds, whereas, a uniform coverage of Al2O3 on WTe2 is observed and likely contributed to the high concentration of intrinsic structural defects. The PEALD behavior is consistent between MoTe2 and WTe2 providing a conformal and linear growth rate (∼0.08 nm/cycle), which correlates with the creation of Te-O and metal-O nucleation sites. However, a thin layer of interfacial Mo or W oxides gradually forms, resulting from the plasma-induced damage in the topmost (1-2) layers. Attempts to enhance the Al2O3/MoTe2 interfacial quality by physically evaporating an Al2O3 seed layer are investigated as well. However, the evaporated Al2O3 process causes thermal damage on MoTe2, necessitating a more 'gentle' ALD technique for the surface passivation.
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Affiliation(s)
- H Zhu
- Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX 75080, United States of America
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30
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Mleczko MJ, Yu AC, Smyth CM, Chen V, Shin YC, Chatterjee S, Tsai YC, Nishi Y, Wallace RM, Pop E. Contact Engineering High-Performance n-Type MoTe 2 Transistors. NANO LETTERS 2019; 19:6352-6362. [PMID: 31314531 DOI: 10.1021/acs.nanolett.9b02497] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Semiconducting MoTe2 is one of the few two-dimensional (2D) materials with a moderate band gap, similar to silicon. However, this material remains underexplored for 2D electronics due to ambient instability and predominantly p-type Fermi level pinning at contacts. Here, we demonstrate unipolar n-type MoTe2 transistors with the highest performance to date, including high saturation current (>400 μA/μm at 80 K and >200 μA/μm at 300 K) and relatively low contact resistance (1.2 to 2 kΩ·μm from 80 to 300 K), achieved with Ag contacts and AlOx encapsulation. We also investigate other contact metals (Sc, Ti, Cr, Au, Ni, Pt), extracting their Schottky barrier heights using an analytic subthreshold model. High-resolution X-ray photoelectron spectroscopy reveals that interfacial metal-Te compounds dominate the contact resistance. Among the metals studied, Sc has the lowest work function but is the most reactive, which we counter by inserting monolayer hexagonal boron nitride between MoTe2 and Sc. These metal-insulator-semiconductor (MIS) contacts partly depin the metal Fermi level and lead to the smallest Schottky barrier for electron injection. Overall, this work improves our understanding of n-type contacts to 2D materials, an important advance for low-power electronics.
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Affiliation(s)
- Michal J Mleczko
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Andrew C Yu
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Christopher M Smyth
- Department of Materials Science and Engineering , University of Texas at Dallas , Richardson , Texas 75083 , United States
| | - Victoria Chen
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Yong Cheol Shin
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Sukti Chatterjee
- Applied Materials, Inc. , Santa Clara , California 95054 , United States
| | - Yi-Chia Tsai
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
- Department of Electrical and Computer Engineering , National Chiao Tung University , Hsinchu 300 , Taiwan
| | - Yoshio Nishi
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
| | - Robert M Wallace
- Department of Materials Science and Engineering , University of Texas at Dallas , Richardson , Texas 75083 , United States
| | - Eric Pop
- Department of Electrical Engineering , Stanford University , Stanford , California 94305 , United States
- Department of Materials Science and Engineering , Stanford University , Stanford , California 94305 , United States
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31
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Nagata M, Shukla S, Nakanishi Y, Liu Z, Lin YC, Shiga T, Nakamura Y, Koyama T, Kishida H, Inoue T, Kanda N, Ohno S, Sakagawa Y, Suenaga K, Shinohara H. Isolation of Single-Wired Transition-Metal Monochalcogenides by Carbon Nanotubes. NANO LETTERS 2019; 19:4845-4851. [PMID: 30798600 DOI: 10.1021/acs.nanolett.8b05074] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The successful isolation of single layers from two-dimensional (2D) van der Waals (vdW)-layered materials has opened new frontiers in condensed matter physics and materials science. Their discovery and unique properties laid the foundation for exploring 1D counterparts. However, the isolation of 1D vdW-wired materials has thus far remained a challenge, and effective techniques are demanded. Here we report the facile synthesis of isolated transition-metal monochalcogenide MoTe nanowires by using carbon nanotubes (CNTs) as molds. Individual nanowires are perfectly separated by CNTs with a minimal interaction, enabling detailed characterization of the single wires. Transmission electron microscopy revealed unusual torsional motion of MoTe nanowires inside CNTs. Confinement of 1D vdW-wired materials to the nanotest tubes might open up possibilities for exploring unprecedented properties of the nanowires and their potential applications such as electromechanical switching devices.
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Affiliation(s)
- Masataka Nagata
- Department of Chemistry , Nagoya University , Nagoya 464-8602 , Japan
| | - Shivani Shukla
- Department of Materials Science and Engineering , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213-3815 , United States
| | - Yusuke Nakanishi
- Department of Chemistry , Nagoya University , Nagoya 464-8602 , Japan
- Institute for Advanced Research , Nagoya University , Nagoya 464-8602 , Japan
- Department of Physics , Tokyo Metropolitan University , Tokyo 192-0397 , Japan
| | - Zheng Liu
- National Institute of Advanced Industrial Science and Technology (AIST) , Nagoya 463-8560 , Japan
- National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba 305-8565 , Japan
| | - Yung-Chang Lin
- National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba 305-8565 , Japan
| | - Takuma Shiga
- Department of Mechanical Engineering , The University of Tokyo , Tokyo 113-8656 , Japan
| | - Yuto Nakamura
- Department of Applied Physics , Nagoya University , Nagoya 464-8603 , Japan
| | - Takeshi Koyama
- Department of Applied Physics , Nagoya University , Nagoya 464-8603 , Japan
| | - Hideo Kishida
- Department of Applied Physics , Nagoya University , Nagoya 464-8603 , Japan
| | - Tsukasa Inoue
- Department of Chemistry , Nagoya University , Nagoya 464-8602 , Japan
| | - Naoyuki Kanda
- Department of Chemistry , Nagoya University , Nagoya 464-8602 , Japan
| | - Shun Ohno
- Gifu High School , Gifu 500-8889 , Japan
| | - Yuki Sakagawa
- Ichinomiya High School , Ichinomiya 491-8533 , Japan
| | - Kazu Suenaga
- National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba 305-8565 , Japan
| | - Hisanori Shinohara
- Department of Chemistry , Nagoya University , Nagoya 464-8602 , Japan
- Institute for Advanced Research , Nagoya University , Nagoya 464-8602 , Japan
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32
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Lee RS, Kim D, Pawar SA, Kim T, Shin JC, Kang SW. van der Waals Epitaxy of High-Mobility Polymorphic Structure of Mo 6Te 6 Nanoplates/MoTe 2 Atomic Layers with Low Schottky Barrier Height. ACS NANO 2019; 13:642-648. [PMID: 30609346 DOI: 10.1021/acsnano.8b07720] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
High contact resistance between two-dimensional (2D) transition metal dichalcogenides (TMDs) and metal electrodes is a practical barrier for applications of 2D TMDs to conventional devices. A promising solution to this is polymorphic integration of 1T'-phase semimetallic and 2H-phase semiconducting TMD crystals, which can lower the Schottky barrier of the TMDs. Here, we demonstrate the van der Waals epitaxy of density-controlled single isolated 1T'-Mo6Te6 nanoplates on 2H-MoTe2 atomic layers by using metal-organic chemical vapor deposition. Importantly, in situ grown 1T'-Mo6Te6 nanoplates significantly reduce the contact resistance of the 2H-MoTe2 atomic layers, providing a record high mobility of 1139 cm2/V·s for Pd/1T'-Mo6Te6/2H-MoTe2 back-gated field-effect transistors, along with a low Schottky barrier height ( qϕb) of 8.7 meV. These results lead to the possibility of ameliorating the high contact resistance faced by other TMDs and, furthermore, offer polymorphic structures for realizing higher-mobility TMD devices.
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Affiliation(s)
- Rochelle S Lee
- Department of Physics , Yeungnam University , Gyeongsan 38541 , Republic of Korea
| | - Donghwan Kim
- Department of Physics , Yeungnam University , Gyeongsan 38541 , Republic of Korea
- Advanced Instrumentation Institute , Korea Research Institute of Standards and Science (KRISS) Daejeon 34113 , Republic of Korea
| | - Sachin A Pawar
- Department of Physics , Yeungnam University , Gyeongsan 38541 , Republic of Korea
| | - TaeWan Kim
- Department of Electrical Engineering and Smart Grid Research Center , Chonbuk National University , Jeonju 54896 , Republic of Korea
| | - Jae Cheol Shin
- Department of Physics , Yeungnam University , Gyeongsan 38541 , Republic of Korea
| | - Sang-Woo Kang
- Advanced Instrumentation Institute , Korea Research Institute of Standards and Science (KRISS) Daejeon 34113 , Republic of Korea
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33
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Huang W, Gan L, Li H, Ma Y, Zhai T. Phase‐Engineered Growth of Ultrathin InSe Flakes by Chemical Vapor Deposition for High‐Efficiency Second Harmonic Generation. Chemistry 2018; 24:15678-15684. [DOI: 10.1002/chem.201803634] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 07/16/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Wenjuan Huang
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering Huazhong University of, Science and Technology (HUST) Wuhan 430074 P. R. China
| | - Lin Gan
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering Huazhong University of, Science and Technology (HUST) Wuhan 430074 P. R. China
| | - Huiqiao Li
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering Huazhong University of, Science and Technology (HUST) Wuhan 430074 P. R. China
| | - Ying Ma
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering Huazhong University of, Science and Technology (HUST) Wuhan 430074 P. R. China
| | - Tianyou Zhai
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering Huazhong University of, Science and Technology (HUST) Wuhan 430074 P. R. China
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34
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Zou YC, Chen ZG, Liu S, Aso K, Zhang C, Kong F, Hong M, Matsumura S, Cho K, Zou J. Atomic Insights into Phase Evolution in Ternary Transition-Metal Dichalcogenides Nanostructures. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1800780. [PMID: 29717813 DOI: 10.1002/smll.201800780] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 03/31/2018] [Indexed: 06/08/2023]
Abstract
Phase engineering through chemical modification can significantly alter the properties of transition-metal dichalcogenides, and allow the design of many novel electronic, photonic, and optoelectronics devices. The atomic-scale mechanism underlying such phase engineering is still intensively investigated but elusive. Here, advanced electron microscopy, combined with density functional theory calculations, is used to understand the phase evolution (hexagonal 2H→monoclinic T'→orthorhombic Td ) in chemical vapor deposition grown Mo1-x W x Te2 nanostructures. Atomic-resolution imaging and electron diffraction indicate that Mo1-x W x Te2 nanostructures have two phases: the pure monoclinic phase in low W-concentrated (0 < x ≤ 10 at.%) samples, and the dual phase of the monoclinic and orthorhombic in high W-concentrated (10 < x < 90 at.%) samples. Such phase coexistence exists with coherent interfaces, mediated by a newly uncovered orthorhombic phase Td '. Td ', preserves the centrosymmetry of T' and provides the possible phase transition path for T'→Td with low energy state. This work enriches the atomic-scale understanding of phase evolution and coexistence in multinary compounds, and paves the way for device applications of new transition-metal dichalcogenides phases and heterostructures.
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Affiliation(s)
- Yi-Chao Zou
- Materials Engineering, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Zhi-Gang Chen
- Materials Engineering, The University of Queensland, Brisbane, QLD, 4072, Australia
- Center of Future Materials, University of Southern Queensland, Springfield, QLD, 4300, Australia
| | - Shijian Liu
- Materials Engineering, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Kohei Aso
- Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Motooka 744, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Chenxi Zhang
- Department of Materials Science & Engineering, The University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Fantai Kong
- Department of Materials Science & Engineering, The University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Min Hong
- Materials Engineering, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Syo Matsumura
- Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Motooka 744, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Kyeongjae Cho
- Department of Materials Science & Engineering, The University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Jin Zou
- Materials Engineering, The University of Queensland, Brisbane, QLD, 4072, Australia
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35
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Yu Y, Wang G, Tan Y, Wu N, Zhang XA, Qin S. Phase-Controlled Growth of One-Dimensional Mo 6Te 6 Nanowires and Two-Dimensional MoTe 2 Ultrathin Films Heterostructures. NANO LETTERS 2018; 18:675-681. [PMID: 29262252 DOI: 10.1021/acs.nanolett.7b03058] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Controllable synthesizing of one-dimensional-two-dimensional (1D-2D) heterostructures and tuning their atomic and electronic structures is nowadays of particular interest due to the extraordinary properties and potential applications. Here, we demonstrate the temperature-induced phase-controlled growth of 1D Mo6Te6-2D MoTe2 heterostructures via molecular beam epitaxy. In situ scanning tunneling microscopy study shows 2D ultrathin films are synthesized at low temperature range, while 1D nanowires gradually arise and dominate as temperature increasing. X-ray photoelectron spectroscopy confirms the good stoichiometry and scanning tunneling spectroscopy reveals the semimetallic property of grown Mo6Te6 nanowires. Through in situ annealing, a phase transition from 2D MoTe2 to 1D Mo6Te6 is induced, thus forming a semimetal-semiconductor junction in atomic level. An upward band bending of 2H-MoTe2 is caused by lateral hole injection from Mo6Te6. The work suggests a new route to synthesize 1D semimetallic transition metal chalcogenide nanowires, which could serve as ultrasmall conducting building blocks and enable band engineering in future 1D-2D heterostructure devices.
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Affiliation(s)
- Yayun Yu
- College of Science, National University of Defense Technology , Changsha 410073, China
- State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University , Beijing 100084, China
| | - Guang Wang
- College of Science, National University of Defense Technology , Changsha 410073, China
- State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University , Beijing 100084, China
- State Key Laboratory of High Performance Computing, National University of Defense Technology , Changsha 410073, China
| | - Yuan Tan
- College of Science, National University of Defense Technology , Changsha 410073, China
| | - Nannan Wu
- College of Science, National University of Defense Technology , Changsha 410073, China
| | - Xue-Ao Zhang
- College of Science, National University of Defense Technology , Changsha 410073, China
- State Key Laboratory of High Performance Computing, National University of Defense Technology , Changsha 410073, China
| | - Shiqiao Qin
- College of Science, National University of Defense Technology , Changsha 410073, China
- State Key Laboratory of High Performance Computing, National University of Defense Technology , Changsha 410073, China
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36
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Zhu H, Wang Q, Cheng L, Addou R, Kim J, Kim MJ, Wallace RM. Defects and Surface Structural Stability of MoTe 2 Under Vacuum Annealing. ACS NANO 2017; 11:11005-11014. [PMID: 29116754 DOI: 10.1021/acsnano.7b04984] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Understanding the structural stability of transition-metal dichalcogenides is necessary to avoid surface/interface degradation. In this work, the structural stability of 2H-MoTe2 with thermal treatments up to 500 °C is studied using scanning tunneling microscopy and scanning transmission electron microscopy. On the exfoliated sample surface at room temperature, atomic subsurface donors originating from excess Te atoms are observed and presented as nanometer-sized, electronically-induced protrusions superimposed with the hexagonal lattice structure of MoTe2. Under a thermal treatment as low as 200 °C, the surface decomposition-induced cluster defects and Te vacancies are readily detected and increase in extent with the increasing temperature. Driven by Te vacancies and thermal energy, intense 60° inversion domain boundaries form resulting in a "wagon wheel" morphology after 400 °C annealing for 15 min. Scanning tunneling spectroscopy identified the electronic states at the domain boundaries and the domain centers. To prevent extensive Te loss at higher temperatures, where Mo6Te6 nanowire formation and substantial desorption-induced etching effects will take place simultaneously, surface and edge passivation with a monolayer graphene coverage on MoTe2 is tested. With this passivation strategy, the structural stability of MoTe2 is greatly enhanced up to 500 °C without apparent structural defects.
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Affiliation(s)
- Hui Zhu
- Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Qingxiao Wang
- Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Lanxia Cheng
- Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Rafik Addou
- Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Jiyoung Kim
- Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Moon J Kim
- Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States
| | - Robert M Wallace
- Department of Materials Science and Engineering, The University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080, United States
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