1
|
Ta HQ, Mendes RG, Liu Y, Yang X, Luo J, Bachmatiuk A, Gemming T, Zeng M, Fu L, Liu L, Rümmeli MH. In Situ Fabrication of Freestanding Single-Atom-Thick 2D Metal/Metallene and 2D Metal/ Metallene Oxide Membranes: Recent Developments. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100619. [PMID: 34459155 PMCID: PMC8529443 DOI: 10.1002/advs.202100619] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/23/2021] [Indexed: 05/13/2023]
Abstract
In recent years, two-dimensional (2D) materials have attracted a lot of research interest as they exhibit several fascinating properties. However, outside of 2D materials derived from van der Waals layered bulk materials only a few other such materials are realized, and it remains difficult to confirm their 2D freestanding structure. Despite that, many metals are predicted to exist as 2D systems. In this review, the authors summarize the recent progress made in the synthesis and characterization of these 2D metals, so called metallenes, and their oxide forms, metallene oxides as free standing 2D structures formed in situ through the use of transmission electron microscopy (TEM) and scanning TEM (STEM) to synthesize these materials. Two primary approaches for forming freestanding monoatomic metallic membranes are identified. In the first, graphene pores as a means to suspend the metallene or metallene oxide and in the second, electron-beam sputtering for the selective etching of metal alloys or thick complex initial materials is employed to obtain freestanding single-atom-thick 2D metal. The data show a growing number of 2D metals/metallenes and 2D metal/ metallene oxides having been confirmed and point to a bright future for further discoveries of these 2D materials.
Collapse
Affiliation(s)
- Huy Q. Ta
- Soochow Institute for Energy and Materials InnovationsCollege of EnergyCollaborative Innovation Center of SuzhouNano Science and TechnologyKey Laboratory of Advanced Carbon MaterialsWearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou215006China
- Institute for Complex MaterialsIFW DresdenP.O. Box D‐01171DresdenGermany
| | - Rafael G. Mendes
- Institute for Complex MaterialsIFW DresdenP.O. Box D‐01171DresdenGermany
| | - Yu Liu
- Soochow Institute for Energy and Materials InnovationsCollege of EnergyCollaborative Innovation Center of SuzhouNano Science and TechnologyKey Laboratory of Advanced Carbon MaterialsWearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou215006China
| | - Xiaoqin Yang
- Soochow Institute for Energy and Materials InnovationsCollege of EnergyCollaborative Innovation Center of SuzhouNano Science and TechnologyKey Laboratory of Advanced Carbon MaterialsWearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou215006China
- School of Energy and Power EngineeringXi'an Jiaotong UniversityNo. 28, Xianning West RoadXi'anShaanxi710049China
| | - Jingping Luo
- School of Energy and Power EngineeringXi'an Jiaotong UniversityNo. 28, Xianning West RoadXi'anShaanxi710049China
| | - Alicja Bachmatiuk
- Material Science & Engineering CenterŁukasiewicz Research Network – PORT Polish Center for Technology DevelopmentUl. Stabłowicka 147Wrocław54‐066Poland
| | - Thomas Gemming
- Institute for Complex MaterialsIFW DresdenP.O. Box D‐01171DresdenGermany
| | - Mengqi Zeng
- College of Chemistry and Molecular ScienceWuhan UniversityWuhan430072China
| | - Lei Fu
- College of Chemistry and Molecular ScienceWuhan UniversityWuhan430072China
| | - Lijun Liu
- School of Energy and Power EngineeringXi'an Jiaotong UniversityNo. 28, Xianning West RoadXi'anShaanxi710049China
| | - Mark H. Rümmeli
- Soochow Institute for Energy and Materials InnovationsCollege of EnergyCollaborative Innovation Center of SuzhouNano Science and TechnologyKey Laboratory of Advanced Carbon MaterialsWearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou215006China
- Institute for Complex MaterialsIFW DresdenP.O. Box D‐01171DresdenGermany
- Centre of Polymer and Carbon MaterialsPolish Academy of SciencesM. Curie‐Sklodowskiej 34Zabrze41‐819Poland
- Center for Energy and Environmental TechnologiesVSB‐Technical University of Ostrava17. Listopadu 15Ostrava708 33Czech Republic
| |
Collapse
|
2
|
Agrawal AV, Kumar N, Kumar M. Strategy and Future Prospects to Develop Room-Temperature-Recoverable NO 2 Gas Sensor Based on Two-Dimensional Molybdenum Disulfide. NANO-MICRO LETTERS 2021; 13:38. [PMID: 33425474 PMCID: PMC7780921 DOI: 10.1007/s40820-020-00558-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/29/2020] [Indexed: 05/12/2023]
Abstract
Nitrogen dioxide (NO2), a hazardous gas with acidic nature, is continuously being liberated in the atmosphere due to human activity. The NO2 sensors based on traditional materials have limitations of high-temperature requirements, slow recovery, and performance degradation under harsh environmental conditions. These limitations of traditional materials are forcing the scientific community to discover future alternative NO2 sensitive materials. Molybdenum disulfide (MoS2) has emerged as a potential candidate for developing next-generation NO2 gas sensors. MoS2 has a large surface area for NO2 molecules adsorption with controllable morphologies, facile integration with other materials and compatibility with internet of things (IoT) devices. The aim of this review is to provide a detailed overview of the fabrication of MoS2 chemiresistance sensors in terms of devices (resistor and transistor), layer thickness, morphology control, defect tailoring, heterostructure, metal nanoparticle doping, and through light illumination. Moreover, the experimental and theoretical aspects used in designing MoS2-based NO2 sensors are also discussed extensively. Finally, the review concludes the challenges and future perspectives to further enhance the gas-sensing performance of MoS2. Understanding and addressing these issues are expected to yield the development of highly reliable and industry standard chemiresistance NO2 gas sensors for environmental monitoring.
Collapse
Affiliation(s)
- Abhay V. Agrawal
- Functional and Renewable Energy Materials Laboratory, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 India
| | - Naveen Kumar
- Functional and Renewable Energy Materials Laboratory, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 India
| | - Mukesh Kumar
- Functional and Renewable Energy Materials Laboratory, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 India
| |
Collapse
|
3
|
Rho Y, Pei J, Wang L, Su Z, Eliceiri M, Grigoropoulos CP. Site-Selective Atomic Layer Precision Thinning of MoS 2 via Laser-Assisted Anisotropic Chemical Etching. ACS APPLIED MATERIALS & INTERFACES 2019; 11:39385-39393. [PMID: 31553575 DOI: 10.1021/acsami.9b14306] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Various exotic optoelectronic properties of two-dimensional (2D) transition metal dichalcogenides (TMDCs) strongly depend on their number of layers, and typically manifest in ultrathin few-layer or monolayer formats. Thus, precise manipulation of thickness and shape is essential to fully access their potential in optoelectronic applications. Here, we demonstrate site-selective atomic layer precision thinning of exfoliated MoS2 flake by laser. The oxidation mediated anisotropic chemical etching initiated from edge defects and progressed by controlled scanning of the laser beam. Thereby, the topmost layer can be preferentially removed in designed patterns without damaging the bottom flake. In addition, we could monitor the deceleration of the thinning by in situ reflectance measurement. The apparent slow down of the thinning rate is attributed to the sharp reduction in the temperature of the flake due to thickness dependent optical properties. Fabrication of monolayer stripes by laser thinning suggests potential applications in nonlinear optical gratings. The proposed thinning method would offer a unique and rather straightforward way to obtain arbitrary shape and thickness of a TMDCs flake for various optoelectronic applications.
Collapse
Affiliation(s)
- Yoonsoo Rho
- Laser Thermal Lab, Department of Mechanical Engineering , University of California , Berkeley , California 94720 , United States
| | - Jiayun Pei
- Department of Mechanical Engineering , Tsinghua University , Beijing 100084 , People's Republic of China
| | - Letian Wang
- Laser Thermal Lab, Department of Mechanical Engineering , University of California , Berkeley , California 94720 , United States
| | - Zhengliang Su
- Laser Thermal Lab, Department of Mechanical Engineering , University of California , Berkeley , California 94720 , United States
| | - Matthew Eliceiri
- Laser Thermal Lab, Department of Mechanical Engineering , University of California , Berkeley , California 94720 , United States
| | - Costas P Grigoropoulos
- Laser Thermal Lab, Department of Mechanical Engineering , University of California , Berkeley , California 94720 , United States
| |
Collapse
|
4
|
Liu X, Hersam MC. Interface Characterization and Control of 2D Materials and Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1801586. [PMID: 30039558 DOI: 10.1002/adma.201801586] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 04/09/2018] [Indexed: 05/28/2023]
Abstract
2D materials and heterostructures have attracted significant attention for a variety of nanoelectronic and optoelectronic applications. At the atomically thin limit, the material characteristics and functionalities are dominated by surface chemistry and interface coupling. Therefore, methods for comprehensively characterizing and precisely controlling surfaces and interfaces are required to realize the full technological potential of 2D materials. Here, the surface and interface properties that govern the performance of 2D materials are introduced. Then the experimental approaches that resolve surface and interface phenomena down to the atomic scale, as well as strategies that allow tuning and optimization of interfacial interactions in van der Waals heterostructures, are systematically reviewed. Finally, a future outlook that delineates the remaining challenges and opportunities for 2D material interface characterization and control is presented.
Collapse
Affiliation(s)
- Xiaolong Liu
- Applied Physics Graduate Program, Northwestern University, 2220 Campus Drive, Evanston, IL, 60208-3108, USA
| | - Mark C Hersam
- Applied Physics Graduate Program, Northwestern University, 2220 Campus Drive, Evanston, IL, 60208-3108, USA
- Department of Materials Science and Engineering, Department of Chemistry, Department of Medicine, Department of Electrical Engineering and Computer Science, Northwestern University, 2220 Campus Drive, Evanston, IL, 60208-3108, USA
| |
Collapse
|
5
|
Huang YT, Dodda A, Schulman DS, Sebastian A, Zhang F, Buzzell D, Terrones M, Feng SP, Das S. Anomalous Corrosion of Bulk Transition Metal Diselenides Leading to Stable Monolayers. ACS APPLIED MATERIALS & INTERFACES 2017; 9:39059-39068. [PMID: 29028313 DOI: 10.1021/acsami.7b13107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this paper we provide insight into an anomalous corrosion process, referred to as electroablation (EA), which converts multilayer flakes of transition metal diselenides like MoSe2 into their corresponding monolayers when micromechanically exfoliated on a conductive electrode and subsequently subjected to a high anodic potential inside a conventional electrochemical cell. Photoluminescence intensity maps and scanning transmission electron microscopy (STEM) images confirmed the single crystalline nature and 2H-hexagonal lattice structure of the remnant monolayer MoSe2 flakes, indicating the superior corrosion stability of the monolayers compared to that of the bulk counterpart. It is noted that the EA technique is a low-cost alternative for high-yield synthesis of single crystalline monolayer MoSe2 at room temperature. We also found that the dynamics of such an electro-oxidation-mediated and self-limiting corrosion process differs significantly for MoSe2 and WSe2. While we were able to engineer the corrosion conditions for the EA process to obtain monolayers of MoSe2, our attempts to obtain monolayers of WSe2 were largely unsuccessful. Finally, we constructed a phenomenological physical chemistry framework to explain such anomalous corrosion processes in transition metal diselenides.
Collapse
Affiliation(s)
- Yu-Ting Huang
- Department of Engineering Science and Mechanics, Pennsylvania State University , University Park, Pennsylvania 16802, United States
- Department of Mechanical Engineering, University of Hong Kong , Pokfulam, Hong Kong
| | - Akhil Dodda
- Department of Mechanical Engineering, Amrita Vishwa Vidyapeetham , Amritapuri, Clappana P.O., Kollam, 690525 Kerala, India
| | - Daniel S Schulman
- Department of Materials Science and Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Amritanand Sebastian
- Department of Engineering Science and Mechanics, Pennsylvania State University , University Park, Pennsylvania 16802, United States
- Department of Electronics and Communication Engineering, Amrita Vishwa Vidyapeetham , Amritapuri, Clappana P.O., Kollam, 690525 Kerala, India
| | - Fu Zhang
- Department of Materials Science and Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Drew Buzzell
- Department of Engineering Science and Mechanics, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Mauricio Terrones
- Department of Materials Science and Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States
- Department of Physics, Pennsylvania State University , University Park, Pennsylvania 16802, United States
- Department of Chemistry, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Shien-Ping Feng
- Department of Mechanical Engineering, University of Hong Kong , Pokfulam, Hong Kong
- The University of Hong Kong-Zhejiang Institute of Research and Innovation (HKU-ZIRI) , Hangzhou, Zhejiang 311300, China
| | - Saptarshi Das
- Department of Engineering Science and Mechanics, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| |
Collapse
|
6
|
Rovetta AAS, Browne MP, Harvey A, Godwin IJ, Coleman JN, Lyons MEG. Cobalt hydroxide nanoflakes and their application as supercapacitors and oxygen evolution catalysts. NANOTECHNOLOGY 2017; 28:375401. [PMID: 28696333 DOI: 10.1088/1361-6528/aa7f1b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Finding alternative routes to access and store energy has become a major issue recently. Transition metal oxides have shown promising behaviour as catalysts and supercapacitors. Recently, liquid exfoliation of bulk metal oxides appears to be an effective route which provides access to two-dimensional (2D) nano-flakes, the size of which can be easily selected. These 2D materials exhibit excellent electrochemical charge storage and catalytic activity for the oxygen evolution reaction. In this study, various sized selected cobalt hydroxide nano-flake materials are fabricated by this time efficient and highly reproducible process. Subsquently, the electrochemical properties of the standard size Co(OH)2 nanoflakes were investigated. The oxide modified electrodes were prepared by spraying the metal oxide flake suspension onto a porous conductive support electrode foam, either glassy carbon or nickel. The cobalt hydroxide/nickel foam system was found to have an overpotential value at 10 mA cm-2 in 1 M NaOH as low as 280 mV and an associated redox capacitance exhibiting numerical values up to 1500 F g-1, thereby making it a viable dual use electrode.
Collapse
Affiliation(s)
- A A S Rovetta
- Trinity Electrochemical Energy Conversion & Electrocatalysis (TEECE) Group, School of Chemistry, Trinity College Dublin, Dublin, Ireland. AMBER and CRANN Institutes, Trinity College Dublin, Dublin, Ireland
| | | | | | | | | | | |
Collapse
|
7
|
Luo W, Yang R, Liu J, Zhao Y, Zhu W, Xia GM. Thermal sublimation: a scalable and controllable thinning method for the fabrication of few-layer black phosphorus. NANOTECHNOLOGY 2017; 28:285301. [PMID: 28574402 DOI: 10.1088/1361-6528/aa76ae] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report uniform layer-by-layer sublimation of black phosphorus under heating below 600 K. The uniformity and crystallinity of BP samples after thermal thinning were confirmed by Raman spectra and Raman mapping. The sublimation rate of BP was around 0.18 nm min-1 at 500 K and 1.15 nm min-1 at 550 K. Both room and high temperature Raman peak intensity ratio [Formula: see text] as functions of BP thickness were established for in situ thickness determination and control. Uniform and crystalline 2 to 4-layer BP flakes with areas from 10 to 1000 μm2 were prepared with this method. No micron scale defects were observed. The sublimation thinning method was shown to be a controllable and scalable approach to prepare high-quality few-layer black phosphorus.
Collapse
Affiliation(s)
- Weijun Luo
- The University of British Columbia, Department of Materials Engineering, Vancouver, B.C., V6T1Z4, Canada
| | | | | | | | | | | |
Collapse
|
8
|
Atomic process of oxidative etching in monolayer molybdenum disulfide. Sci Bull (Beijing) 2017; 62:846-851. [PMID: 36659318 DOI: 10.1016/j.scib.2017.05.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 01/21/2023]
Abstract
The microscopic process of oxidative etching of two-dimensional molybdenum disulfide (2D MoS2) at an atomic scale is investigated using a correlative transmission electron microscope (TEM)-etching study. MoS2 flakes on graphene TEM grids are precisely tracked and characterized by TEM before and after the oxidative etching. This allows us to determine the structural change with an atomic resolution on the edges of the domains, of well-oriented triangular pits and along the grain boundaries. We observe that the etching mostly starts from the open edges, grain boundaries and pre-existing atomic defects. A zigzag Mo edge is assigned as the dominant termination of the triangular pits, and profound terraces and grooves are observed on the etched edges. Based on the statistical TEM analysis, we reveal possible routes for the kinetics of the oxidative etching in 2D MoS2, which should also be applicable for other 2D transition metal dichalcogenide materials like MoSe2 and WS2.
Collapse
|
9
|
Li Y, Cain JD, Hanson ED, Murthy AA, Hao S, Shi F, Li Q, Wolverton C, Chen X, Dravid VP. Au@MoS 2 Core-Shell Heterostructures with Strong Light-Matter Interactions. NANO LETTERS 2016; 16:7696-7702. [PMID: 27782405 DOI: 10.1021/acs.nanolett.6b03764] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
There are emerging opportunities to harness diverse and complex geometric architectures based on nominal two-dimensional atomically layered structures. Herein we report synthesis and properties of a new core-shell heterostructure, termed Au@MoS2, where the Au nanoparticle is snugly and contiguously encapsulated by few shells of MoS2 atomic layers. The heterostructures were synthesized by direct growth of multilayer fullerene-like MoS2 shell on Au nanoparticle cores. The Au@MoS2 heterostructures exhibit interesting light-matter interactions due to the structural curvature of MoS2 shell and the plasmonic effect from the underlying Au nanoparticle core. We observed significantly enhanced Raman scattering and photoluminescence emission on these heterostructures. We attribute these enhancements to the surface plasmon-induced electric field, which simulations show to mainly localize within the MoS2 shell. We also found potential evidence for the charge transfer-induced doping effect on the MoS2 shell. The DFT calculations further reveal that the structural curvature of MoS2 shell results in a modification of its electronic structure, which may facilitate the charge transfer from MoS2 to Au. Such Au@MoS2 core-shell heterostructures have the potential for future optoelectronic devices, optical imaging, and other energy-environmental applications.
Collapse
Affiliation(s)
- Yuan Li
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| | - Jeffrey D Cain
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| | - Eve D Hanson
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| | - Akshay A Murthy
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| | - Shiqiang Hao
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| | - Fengyuan Shi
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| | - Qianqian Li
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| | - Chris Wolverton
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| | - Xinqi Chen
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| | - Vinayak P Dravid
- Department of Materials Science and Engineering, ‡Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, and §International Institute for Nanotechnology (IIN), Northwestern University , Evanston, Illinois 60208, United States
| |
Collapse
|
10
|
Cain JD, Shi F, Wu J, Dravid VP. Growth Mechanism of Transition Metal Dichalcogenide Monolayers: The Role of Self-Seeding Fullerene Nuclei. ACS NANO 2016; 10:5440-5. [PMID: 27138735 DOI: 10.1021/acsnano.6b01705] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Due to their unique optoelectronic properties and potential for next generation devices, monolayer transition metal dichalcogenides (TMDs) have attracted a great deal of interest since the first observation of monolayer MoS2 a few years ago. While initially isolated in monolayer form by mechanical exfoliation, the field has evolved to more sophisticated methods capable of direct growth of large-area monolayer TMDs. Chemical vapor deposition (CVD) is the technique used most prominently throughout the literature and is based on the sulfurization of transition metal oxide precursors. CVD-grown monolayers exhibit excellent quality, and this process is widely used in studies ranging from the fundamental to the applied. However, little is known about the specifics of the nucleation and growth mechanisms occurring during the CVD process. In this study, we have investigated the nucleation centers or "seeds" from which monolayer TMDs typically grow. This was accomplished using aberration-corrected scanning transmission electron microscopy to analyze the structure and composition of the nuclei present in CVD-grown MoS2-MoSe2 alloys. We find that monolayer growth proceeds from nominally oxi-chalcogenide nanoparticles which act as heterogeneous nucleation sites for monolayer growth. The oxi-chalcogenide nanoparticles are typically encased in a fullerene-like shell made of the TMD. Using this information, we propose a step-by-step nucleation and growth mechanism for monolayer TMDs. Understanding this mechanism may pave the way for precise control over the synthesis of 2D materials, heterostructures, and related complexes.
Collapse
Affiliation(s)
- Jeffrey D Cain
- Department of Materials Science and Engineering, ‡International Institute for Nanotechnology, and §Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University , Evanston, Illinois 60208, United States
| | - Fengyuan Shi
- Department of Materials Science and Engineering, ‡International Institute for Nanotechnology, and §Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University , Evanston, Illinois 60208, United States
| | - Jinsong Wu
- Department of Materials Science and Engineering, ‡International Institute for Nanotechnology, and §Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University , Evanston, Illinois 60208, United States
| | - Vinayak P Dravid
- Department of Materials Science and Engineering, ‡International Institute for Nanotechnology, and §Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University , Evanston, Illinois 60208, United States
| |
Collapse
|
11
|
Tai G, Zeng T, Yu J, Zhou J, You Y, Wang X, Wu H, Sun X, Hu T, Guo W. Fast and large-area growth of uniform MoS2 monolayers on molybdenum foils. NANOSCALE 2016; 8:2234-2241. [PMID: 26743938 DOI: 10.1039/c5nr07226c] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A controllable synthesis of two-dimensional crystal monolayers in a large area is a prerequisite for potential applications, but the growth of transition metal dichalcogenide monolayers in a large area with spatial homogeneity remains a great challenge. Here we report a novel and efficient method to fabricate large-scale MoS2 monolayers by direct sulfurization of pre-annealed molybdenum foil surfaces with large grain boundaries of more than 50 μm in size at elevated temperatures. Continuous MoS2 monolayers can be formed uniformly by sulfurizing the Mo foils in sulfur vapor at 600 °C within 1 min. At a lower temperature even down to 500 °C, uniform MoS2 monolayers can still be obtained but in a much longer sulfurizing duration. It is demonstrated that the formed monolayers can be nondestructively transferred onto arbitrary substrates by removing the Mo foil using diluted ferric chloride solution and can be successfully fabricated into photodetectors. The results show a novel avenue to efficiently fabricate two-dimensional crystals in a large area in a highly controllable way and should have great potential for the development of large-scale applications of two-dimensional crystals in electrophotonic systems.
Collapse
Affiliation(s)
- Guoan Tai
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| | - Tian Zeng
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. and School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Jin Yu
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| | - Jianxin Zhou
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| | - Yuncheng You
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. and School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Xufeng Wang
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. and School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Hongrong Wu
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| | - Xu Sun
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| | - Tingsong Hu
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. and School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Wanlin Guo
- The State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education and Institute of Nanoscience, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| |
Collapse
|
12
|
Li X, Li X, Zang X, Zhu M, He Y, Wang K, Xie D, Zhu H. Role of hydrogen in the chemical vapor deposition growth of MoS2 atomic layers. NANOSCALE 2015; 7:8398-8404. [PMID: 25876755 DOI: 10.1039/c5nr00904a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Hydrogen plays a crucial role in the chemical vapor deposition (CVD) growth of graphene. Here, we have revealed the roles of hydrogen in the two-step CVD growth of MoS2. Our study demonstrates that hydrogen acts as the following: (i) an inhibitor of the thermal-induced etching effect in the continuous film growth process; and (ii) a promoter of the desulfurization reaction by decreasing the S/Mo atomic ratio and the oxidation reaction of the obtained MoSx (0 < x < 2) films. A high hydrogen content of more than 100% in argon forms nano-sized circle-like defects and damages the continuity and uniformity of the film. Continuous MoS2 films with a high crystallinity and a nearly perfect S/Mo atomic ratio were finally obtained after sulfurization annealing with a hydrogen content in the range of 20%-80%. This insightful understanding reveals the crucial roles of hydrogen in the CVD growth of MoS2 and paves the way for the controllable synthesis of two-dimensional materials.
Collapse
Affiliation(s)
- Xiao Li
- School of Materials Science and Engineering, State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084, China.
| | | | | | | | | | | | | | | |
Collapse
|