1
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Park J, Jung J, Kim MS, Lim CM, Choi JE, Kim N, Kim JH, Chung CW. Damage-Free Plasma Source for Atomic-Scale Processing. NANO LETTERS 2024. [PMID: 39239915 DOI: 10.1021/acs.nanolett.4c02598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/07/2024]
Abstract
As atomic-scale etching and deposition processes become necessary for manufacturing logic and memory devices at the sub-5 nm node, the limitations of conventional plasma technology are becoming evident. For atomic-scale processes, precise critical dimension control at the sub-1 nm scale without plasma-induced damage and high selectivity between layers are required. In this paper, a plasma with very low electron temperature is applied for damage-free processing on the atomic scale. In plasmas with an ultralow electron temperature (ULET, Te < 0.5 eV), ion energies are very low, and the ion energy distribution is narrow. The absence of physical damage in ULET plasma is verified by exposing 2D structural material. In the ULET plasma, charging damage and radiation damage are also expected to be suppressed due to the extremely low Te. This ULET plasma source overcomes the limitations of conventional plasma sources and provides insights to achieve damage-free atomic-scale processes.
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Affiliation(s)
- Junyoung Park
- Department of Electrical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Jiwon Jung
- Department of Electrical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Min-Seok Kim
- Department of Electrical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Chang-Min Lim
- Department of Electrical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Jung-Eun Choi
- Department of Electrical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Nayeon Kim
- Department of Electrical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Ju-Ho Kim
- Department of Electrical Engineering, Hanyang University, Seoul 04763, South Korea
| | - Chin-Wook Chung
- Department of Electrical Engineering, Hanyang University, Seoul 04763, South Korea
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2
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Han SS, Shin JC, Ghanipour A, Lee JH, Lee SG, Kim JH, Chung HS, Lee GH, Jung Y. High Mobility Transistors and Flexible Optical Synapses Enabled by Wafer-Scale Chemical Transformation of Pt-Based 2D Layers. ACS APPLIED MATERIALS & INTERFACES 2024; 16:36599-36608. [PMID: 38949620 DOI: 10.1021/acsami.4c06540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Electronic devices employing two-dimensional (2D) van der Waals (vdW) transition-metal dichalcogenide (TMD) layers as semiconducting channels often exhibit limited performance (e.g., low carrier mobility), in part, due to their high contact resistances caused by interfacing non-vdW three-dimensional (3D) metal electrodes. Herein, we report that this intrinsic contact issue can be efficiently mitigated by forming the 2D/2D in-plane junctions of 2D semiconductor channels seamlessly interfaced with 2D metal electrodes. For this, we demonstrated the selectively patterned conversion of semiconducting 2D PtSe2 (channels) to metallic 2D PtTe2 (electrodes) layers by employing a wafer-scale low-temperature chemical vapor deposition (CVD) process. We investigated a variety of field-effect transistors (FETs) employing wafer-scale CVD-2D PtSe2/2D PtTe2 heterolayers and identified that silicon dioxide (SiO2) top-gated FETs exhibited an extremely high hole mobility of ∼120 cm2 V-1 s-1 at room temperature, significantly surpassing performances with previous wafer-scale 2D PtSe2-based FETs. The low-temperature nature of the CVD method further allowed for the direct fabrication of wafer-scale arrays of 2D PtSe2/2D PtTe2 heterolayers on polyamide (PI) substrates, which intrinsically displayed optical pulse-induced artificial synaptic behaviors. This study is believed to vastly broaden the applicability of 2D TMD layers for next-generation, high-performance electronic devices with unconventional functionalities.
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Affiliation(s)
- Sang Sub Han
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
| | - June-Chul Shin
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Alireza Ghanipour
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
| | - Ji-Hyun Lee
- Electron Microscopy Group of Materials Science, Korea Basic Science Institute, Daejeon 34133, Republic of Korea
| | - Sang-Gil Lee
- Electron Microscopy Group of Materials Science, Korea Basic Science Institute, Daejeon 34133, Republic of Korea
| | - Jung Han Kim
- Department of Materials Science and Engineering, Dong-A University, Busan 49315, Republic of Korea
| | - Hee-Suk Chung
- Electron Microscopy Group of Materials Science, Korea Basic Science Institute, Daejeon 34133, Republic of Korea
| | - Gwan-Hyoung Lee
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Yeonwoong Jung
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- Department of Materials Science and Engineering, University of Central Florida, Orlando, Florida 32826, United States
- Department of Electrical and Computer Engineering, University of Central Florida, Orlando, Florida 32826, United States
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3
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Jadhav PR, Kolhe PT, Ghemud VS, Shelke PN, Patole SP, Dhole SD, Dahiwale SS. Modification of WS 2thin film properties using high dose gamma irradiation. NANOTECHNOLOGY 2024; 35:335701. [PMID: 38722286 DOI: 10.1088/1361-6528/ad4901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 05/09/2024] [Indexed: 05/29/2024]
Abstract
The tunability of the transition metal dichalcogenide properties has gained attention from numerous researchers due to their wide application in various fields including quantum technology. In the present work, WS2has been deposited on fluorine doped tin oxide substrate and its properties have been studied systematically. These samples were irradiated using gamma radiation for various doses, and the effect on structural, morphological, optical and electrical properties has been reported. The crystallinity of the material is observed to be decreased, and the results are well supported by x-ray diffraction, Raman spectroscopy techniques. The increase in grain boundaries has been supported by the agglomeration observed in the scanning electron microscopy micrographs. The XPS results of WS2after gamma irradiation show evolution of oxygen, carbon, C=O, W-O and SO4-2peaks, confirming the addition of impurities and formation of point defect. The gamma irradiation creates point defects, and their density increases considerably with increasing gamma dosage. These defects crucially altered the structural, optical and electrical properties of the material. The reduction in the optical band gap with increased gamma irradiation is evident from the absorption spectra and respective Tauc plots. TheI-Vgraphs show a 1000-fold increase in the saturation current after 100 kGy gamma irradiation dose. This work has explored the gamma irradiation effect on the WS2and suggests substantial modification in the material and enhancement in electrical properties.
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Affiliation(s)
- P R Jadhav
- Department of Physics, Savitribai Phule Pune University, Pune 411007, India
- Department of Physics, PDEA's Baburaoji Gholap College, Pune 411027, India
| | - P T Kolhe
- Department of Physics, Savitribai Phule Pune University, Pune 411007, India
- Department of Physics, Sangamner Nagarpalika Arts, DJM Commerce and BNS Science College, Sangamner 422605, India
| | - V S Ghemud
- Department of Physics, Savitribai Phule Pune University, Pune 411007, India
- Department of Physics, BJS's Arts, Science & Commerce College, Pune 412207, India
| | - P N Shelke
- Department of Physics, PDEA's Baburaoji Gholap College, Pune 411027, India
- Department of Physics, Waghire College, Saswad, 412301, India
| | - S P Patole
- Department of Physics, Khalifa University of Science and Technology, Abu Dhabi, 127788, United Arab Emirates
| | - S D Dhole
- Department of Physics, Savitribai Phule Pune University, Pune 411007, India
| | - S S Dahiwale
- Department of Physics, Savitribai Phule Pune University, Pune 411007, India
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4
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Sovizi S, Angizi S, Ahmad Alem SA, Goodarzi R, Taji Boyuk MRR, Ghanbari H, Szoszkiewicz R, Simchi A, Kruse P. Plasma Processing and Treatment of 2D Transition Metal Dichalcogenides: Tuning Properties and Defect Engineering. Chem Rev 2023; 123:13869-13951. [PMID: 38048483 PMCID: PMC10756211 DOI: 10.1021/acs.chemrev.3c00147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 08/31/2023] [Accepted: 11/09/2023] [Indexed: 12/06/2023]
Abstract
Two-dimensional transition metal dichalcogenides (TMDs) offer fascinating opportunities for fundamental nanoscale science and various technological applications. They are a promising platform for next generation optoelectronics and energy harvesting devices due to their exceptional characteristics at the nanoscale, such as tunable bandgap and strong light-matter interactions. The performance of TMD-based devices is mainly governed by the structure, composition, size, defects, and the state of their interfaces. Many properties of TMDs are influenced by the method of synthesis so numerous studies have focused on processing high-quality TMDs with controlled physicochemical properties. Plasma-based methods are cost-effective, well controllable, and scalable techniques that have recently attracted researchers' interest in the synthesis and modification of 2D TMDs. TMDs' reactivity toward plasma offers numerous opportunities to modify the surface of TMDs, including functionalization, defect engineering, doping, oxidation, phase engineering, etching, healing, morphological changes, and altering the surface energy. Here we comprehensively review all roles of plasma in the realm of TMDs. The fundamental science behind plasma processing and modification of TMDs and their applications in different fields are presented and discussed. Future perspectives and challenges are highlighted to demonstrate the prominence of TMDs and the importance of surface engineering in next-generation optoelectronic applications.
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Affiliation(s)
- Saeed Sovizi
- Faculty of
Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Shayan Angizi
- Department
of Chemistry and Chemical Biology, McMaster
University, Hamilton, Ontario L8S 4M1, Canada
| | - Sayed Ali Ahmad Alem
- Chair in
Chemistry of Polymeric Materials, Montanuniversität
Leoben, Leoben 8700, Austria
| | - Reyhaneh Goodarzi
- School of
Metallurgy and Materials Engineering, Iran
University of Science and Technology (IUST), Narmak, 16846-13114, Tehran, Iran
| | | | - Hajar Ghanbari
- School of
Metallurgy and Materials Engineering, Iran
University of Science and Technology (IUST), Narmak, 16846-13114, Tehran, Iran
| | - Robert Szoszkiewicz
- Faculty of
Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Abdolreza Simchi
- Department
of Materials Science and Engineering and Institute for Nanoscience
and Nanotechnology, Sharif University of
Technology, 14588-89694 Tehran, Iran
- Center for
Nanoscience and Nanotechnology, Institute for Convergence Science
& Technology, Sharif University of Technology, 14588-89694 Tehran, Iran
| | - Peter Kruse
- Department
of Chemistry and Chemical Biology, McMaster
University, Hamilton, Ontario L8S 4M1, Canada
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5
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Wang X, Pettes MT, Wang Y, Zhu JX, Dhall R, Song C, Jones AC, Ciston J, Yoo J. Enhanced Exciton-to-Trion Conversion by Proton Irradiation of Atomically Thin WS 2. NANO LETTERS 2023; 23:3754-3761. [PMID: 37094221 DOI: 10.1021/acs.nanolett.2c04987] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Defect engineering of van der Waals semiconductors has been demonstrated as an effective approach to manipulate the structural and functional characteristics toward dynamic device controls, yet correlations between physical properties with defect evolution remain underexplored. Using proton irradiation, we observe an enhanced exciton-to-trion conversion of the atomically thin WS2. The altered excitonic states are closely correlated with nanopore induced atomic displacement, W nanoclusters, and zigzag edge terminations, verified by scanning transmission electron microscopy, photoluminescence, and Raman spectroscopy. Density functional theory calculation suggests that nanopores facilitate formation of in-gap states that act as sinks for free electrons to couple with excitons. The ion energy loss simulation predicts a dominating electron ionization effect upon proton irradiation, providing further evidence on band perturbations and nanopore formation without destroying the overall crystallinity. This study provides a route in tuning the excitonic properties of van der Waals semiconductors using an irradiation-based defect engineering approach.
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Affiliation(s)
- Xuejing Wang
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Michael Thompson Pettes
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Yongqiang Wang
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Materials Science in Radiation and Dynamics Extremes (MST-8), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Jian-Xin Zhu
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Physics of Condensed Matter and Complex Systems (T-4), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Rohan Dhall
- National Center for Electron Microscopy (NCEM), Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Chengyu Song
- National Center for Electron Microscopy (NCEM), Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Andrew C Jones
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Jim Ciston
- National Center for Electron Microscopy (NCEM), Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jinkyoung Yoo
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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6
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Grünleitner T, Henning A, Bissolo M, Zengerle M, Gregoratti L, Amati M, Zeller P, Eichhorn J, Stier AV, Holleitner AW, Finley JJ, Sharp ID. Real-Time Investigation of Sulfur Vacancy Generation and Passivation in Monolayer Molybdenum Disulfide via in situ X-ray Photoelectron Spectromicroscopy. ACS NANO 2022; 16:20364-20375. [PMID: 36516326 DOI: 10.1021/acsnano.2c06317] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Understanding the chemical and electronic properties of point defects in two-dimensional materials, as well as their generation and passivation, is essential for the development of functional systems, spanning from next-generation optoelectronic devices to advanced catalysis. Here, we use synchrotron-based X-ray photoelectron spectroscopy (XPS) with submicron spatial resolution to create sulfur vacancies (SVs) in monolayer MoS2 and monitor their chemical and electronic properties in situ during the defect creation process. X-ray irradiation leads to the emergence of a distinct Mo 3d spectral feature associated with undercoordinated Mo atoms. Real-time analysis of the evolution of this feature, along with the decrease of S content, reveals predominant monosulfur vacancy generation at low doses and preferential disulfur vacancy generation at high doses. Formation of these defects leads to a shift of the Fermi level toward the valence band (VB) edge, introduction of electronic states within the VB, and formation of lateral pn junctions. These findings are consistent with theoretical predictions that SVs serve as deep acceptors and are not responsible for the ubiquitous n-type conductivity of MoS2. In addition, we find that these defects are metastable upon short-term exposure to ambient air. By contrast, in situ oxygen exposure during XPS measurements enables passivation of SVs, resulting in partial elimination of undercoordinated Mo sites and reduction of SV-related states near the VB edge. Correlative Raman spectroscopy and photoluminescence measurements confirm our findings of localized SV generation and passivation, thereby demonstrating the connection between chemical, structural, and optoelectronic properties of SVs in MoS2.
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Affiliation(s)
- Theresa Grünleitner
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Alex Henning
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Michele Bissolo
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Marisa Zengerle
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Luca Gregoratti
- Elettra - Sincrotrone Trieste SCpA, AREA Science Park, Strada Statale 14 km 163.5, 34149, Trieste, Italy
| | - Matteo Amati
- Elettra - Sincrotrone Trieste SCpA, AREA Science Park, Strada Statale 14 km 163.5, 34149, Trieste, Italy
| | - Patrick Zeller
- Elettra - Sincrotrone Trieste SCpA, AREA Science Park, Strada Statale 14 km 163.5, 34149, Trieste, Italy
| | - Johanna Eichhorn
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Andreas V Stier
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Alexander W Holleitner
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Jonathan J Finley
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Ian D Sharp
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching, Germany
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7
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Kirubasankar B, Won YS, Adofo LA, Choi SH, Kim SM, Kim KK. Atomic and structural modifications of two-dimensional transition metal dichalcogenides for various advanced applications. Chem Sci 2022; 13:7707-7738. [PMID: 35865881 PMCID: PMC9258346 DOI: 10.1039/d2sc01398c] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/18/2022] [Indexed: 12/14/2022] Open
Abstract
Two-dimensional (2D) transition metal dichalcogenides (TMDs) and their heterostructures have attracted significant interest in both academia and industry because of their unusual physical and chemical properties. They offer numerous applications, such as electronic, optoelectronic, and spintronic devices, in addition to energy storage and conversion. Atomic and structural modifications of van der Waals layered materials are required to achieve unique and versatile properties for advanced applications. This review presents a discussion on the atomic-scale and structural modifications of 2D TMDs and their heterostructures via post-treatment. Atomic-scale modifications such as vacancy generation, substitutional doping, functionalization and repair of 2D TMDs and structural modifications including phase transitions and construction of heterostructures are discussed. Such modifications on the physical and chemical properties of 2D TMDs enable the development of various advanced applications including electronic and optoelectronic devices, sensing, catalysis, nanogenerators, and memory and neuromorphic devices. Finally, the challenges and prospects of various post-treatment techniques and related future advanced applications are addressed.
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Affiliation(s)
- Balakrishnan Kirubasankar
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Department of Chemistry, Sookmyung Women's University Seoul 14072 South Korea
| | - Yo Seob Won
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
| | - Laud Anim Adofo
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
| | - Soo Ho Choi
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
| | - Soo Min Kim
- Department of Chemistry, Sookmyung Women's University Seoul 14072 South Korea
| | - Ki Kang Kim
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
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8
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Ouyang Y, Zhou Y, Zhang Y, Li Q, Wang J. Double-edged roles of intrinsic defects in two-dimensional MoS2. TRENDS IN CHEMISTRY 2022. [DOI: 10.1016/j.trechm.2022.02.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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9
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Hole doping effect of MoS 2 via electron capture of He + ion irradiation. Sci Rep 2021; 11:23590. [PMID: 34880289 PMCID: PMC8654839 DOI: 10.1038/s41598-021-02932-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/23/2021] [Indexed: 01/02/2023] Open
Abstract
Beyond the general purpose of noble gas ion sputtering, which is to achieve functional defect engineering of two-dimensional (2D) materials, we herein report another positive effect of low-energy (100 eV) He+ ion irradiation: converting n-type MoS2 to p-type by electron capture through the migration of the topmost S atoms. The electron capture ability via He+ ion irradiation is valid for supported bilayer MoS2; however, it is limited at supported monolayer MoS2 because the charges on the underlying substrates transfer into the monolayer under the current condition for He+ ion irradiation. Our technique provides a stable and universal method for converting n-type 2D transition metal dichalcogenides (TMDs) into p-type semiconductors in a controlled fashion using low-energy He+ ion irradiation.
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10
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Ng LR, Chen GF, Lin SH. Generating large out-of-plane piezoelectric properties of atomically thin MoS 2via defect engineering. Phys Chem Chem Phys 2021; 23:23945-23952. [PMID: 34657948 DOI: 10.1039/d1cp02976b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We calculated the piezoelectric properties of asymmetrically defected MoS2 using density functional theory. By creating uneven numbers of defects on either side of two-dimensional MoS2, the out-of-plane centrosymmetry of the charge distribution is clearly broken, and the out-of-plane piezoelectric response is induced. The largest out-of-plane piezoelectric response is associated with the highest defect ratio for MoS2 to be semiconducting. We calculated the critical defect density of the metal-insulator transition of the asymmetrically defected MoS2 to be 9.90 × 1014 cm-2 and chemical formula MoS1.22. The d33 of the multilayer of optimally defected MoS2 is found to be greater than those of AlN and ZnO, and in the same order of magnitude as lead zirconate titanate. All two-dimensional transition metal dichalcogenides can in principle be fabricated as piezoelectric with this approach. The required defect engineering is readily available with various types of ion irradiation or plasma treatment. By controlling the dose of the ion, the defect ratio and hence the piezoelectricity can be tuned. Such asymmetrically defected transition metal dichalcogenides can easily be integrated into two-dimensional transition metal dichalcogenide based devices, which is hard for conventional piezoelectric thin films to rival.
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Affiliation(s)
- Li-Ren Ng
- Department of Materials and Optoelectronic Science, Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
| | - Guan-Fu Chen
- Department of Materials and Optoelectronic Science, Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
| | - Shi-Hsin Lin
- Department of Materials and Optoelectronic Science, Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
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11
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Amsterdam SH, Stanev TK, Wang L, Zhou Q, Irgen-Gioro S, Padgaonkar S, Murthy AA, Sangwan VK, Dravid VP, Weiss EA, Darancet P, Chan MKY, Hersam MC, Stern NP, Marks TJ. Mechanistic Investigation of Molybdenum Disulfide Defect Photoluminescence Quenching by Adsorbed Metallophthalocyanines. J Am Chem Soc 2021; 143:17153-17161. [PMID: 34613735 DOI: 10.1021/jacs.1c07795] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lattice defects play an important role in determining the optical and electrical properties of monolayer semiconductors such as MoS2. Although the structures of various defects in monolayer MoS2 are well studied, little is known about the nature of the fluorescent defect species and their interaction with molecular adsorbates. In this study, the quenching of the low-temperature defect photoluminescence (PL) in MoS2 is investigated following the deposition of metallophthalocyanines (MPcs). The quenching is found to significantly depend on the identity of the phthalocyanine metal, with the quenching efficiency decreasing in the order CoPc > CuPc > ZnPc, and almost no quenching by metal-free H2Pc is observed. Time-correlated single photon counting (TCSPC) measurements corroborate the observed trend, indicating a decrease in the defect PL lifetime upon MPc adsorption, and the gate voltage-dependent PL reveals the suppression of the defect emission even at large Fermi level shifts. Density functional theory modeling argues that the MPc complexes stabilize dark negatively charged defects over luminescent neutral defects through an electrostatic local gating effect. These results demonstrate the control of defect-based excited-state decay pathways via molecular electronic structure tuning, which has broad implications for the design of mixed-dimensional optoelectronic devices.
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Affiliation(s)
- Samuel H Amsterdam
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Teodor K Stanev
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
| | - Luqing Wang
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Qunfei Zhou
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Shawn Irgen-Gioro
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Suyog Padgaonkar
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Akshay A Murthy
- Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Vinod K Sangwan
- Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Vinayak P Dravid
- Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States.,Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Evanston, Illinois 60208, United States
| | - Emily A Weiss
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States.,Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States.,Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Pierre Darancet
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Northwestern Argonne Institute of Science and Engineering, Evanston, Illinois 60208, United States
| | - Maria K Y Chan
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Northwestern Argonne Institute of Science and Engineering, Evanston, Illinois 60208, United States
| | - Mark C Hersam
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States.,Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States.,Department of Electrical and Computer Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Nathaniel P Stern
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
| | - Tobin J Marks
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States.,Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
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12
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Liang Q, Zhang Q, Zhao X, Liu M, Wee ATS. Defect Engineering of Two-Dimensional Transition-Metal Dichalcogenides: Applications, Challenges, and Opportunities. ACS NANO 2021; 15:2165-2181. [PMID: 33449623 DOI: 10.1021/acsnano.0c09666] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Atomic defects, being the most prevalent zero-dimensional topological defects, are ubiquitous in a wide range of 2D transition-metal dichalcogenides (TMDs). They could be intrinsic, formed during the initial sample growth, or created by postprocessing. Despite the majority of TMDs being largely unaffected after losing chalcogen atoms in the outermost layer, a spectrum of properties, including optical, electrical, and chemical properties, can be significantly modulated, and potentially invoke applicable functionalities utilized in many applications. Hence, controlling chalcogen atomic defects provides an alternative avenue for engineering a wide range of physical and chemical properties of 2D TMDs. In this article, we review recent progress on the role of chalcogen atomic defects in engineering 2D TMDs, with a particular focus on device performance improvements. Various approaches for creating chalcogen atomic defects including nonstoichiometric synthesis and postgrowth treatment, together with their characterization and interpretation are systematically overviewed. The tailoring of optical, electrical, and magnetic properties, along with the device performance enhancement in electronic, optoelectronic, chemical sensing, biomedical, and catalytic activity are discussed in detail. Postformation dynamic evolution and repair of chalcogen atomic defects are also introduced. Finally, we offer our perspective on the challenges and opportunities in this field.
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Affiliation(s)
- Qijie Liang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
| | - Qian Zhang
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore
| | - Xiaoxu Zhao
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore
| | - Meizhuang Liu
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
| | - Andrew T S Wee
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
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13
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Song C, Noh G, Kim TS, Kang M, Song H, Ham A, Jo MK, Cho S, Chai HJ, Cho SR, Cho K, Park J, Song S, Song I, Bang S, Kwak JY, Kang K. Growth and Interlayer Engineering of 2D Layered Semiconductors for Future Electronics. ACS NANO 2020; 14:16266-16300. [PMID: 33301290 DOI: 10.1021/acsnano.0c06607] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Layered materials that do not form a covalent bond in a vertical direction can be prepared in a few atoms to one atom thickness without dangling bonds. This distinctive characteristic of limiting thickness around the sub-nanometer level allowed scientists to explore various physical phenomena in the quantum realm. In addition to the contribution to fundamental science, various applications were proposed. Representatively, they were suggested as a promising material for future electronics. This is because (i) the dangling-bond-free nature inhibits surface scattering, thus carrier mobility can be maintained at sub-nanometer range; (ii) the ultrathin nature allows the short-channel effect to be overcome. In order to establish fundamental discoveries and utilize them in practical applications, appropriate preparation methods are required. On the other hand, adjusting properties to fit the desired application properly is another critical issue. Hence, in this review, we first describe the preparation method of layered materials. Proper growth techniques for target applications and the growth of emerging materials at the beginning stage will be extensively discussed. In addition, we suggest interlayer engineering via intercalation as a method for the development of artificial crystal. Since infinite combinations of the host-intercalant combination are possible, it is expected to expand the material system from the current compound system. Finally, inevitable factors that layered materials must face to be used as electronic applications will be introduced with possible solutions. Emerging electronic devices realized by layered materials are also discussed.
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Affiliation(s)
- Chanwoo Song
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Gichang Noh
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- Center for Electronic Materials, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - Tae Soo Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Minsoo Kang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Hwayoung Song
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Ayoung Ham
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Min-Kyung Jo
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- Operando Methodology and Measurement Team, Interdisciplinary Materials Measurement Institute, Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Korea
| | - Seorin Cho
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Hyun-Jun Chai
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Seong Rae Cho
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Kiwon Cho
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Jeongwon Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Seungwoo Song
- Operando Methodology and Measurement Team, Interdisciplinary Materials Measurement Institute, Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Korea
| | - Intek Song
- Department of Applied Chemistry, Andong National University, Andong 36728, Korea
| | - Sunghwan Bang
- Materials & Production Engineering Research Institute, LG Electronics, Pyeongtaek-si 17709, Korea
| | - Joon Young Kwak
- Center for Electronic Materials, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - Kibum Kang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
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14
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Wang R, Han J, Yang B, Wang X, Zhang X, Song B. Defect Engineering in Metastable Phases of Transition-Metal Dichalcogenides for Electrochemical Applications. Chem Asian J 2020; 15:3961-3972. [PMID: 32865315 DOI: 10.1002/asia.202000883] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/28/2020] [Indexed: 11/10/2022]
Abstract
Metastable metallic phases of transition-metal dichalcogenide (TMD) nanomaterials have displayed excellent performance and emerged as promising candidates for sustainable energy sources low-cost storage and conversion because of their two-dimensional (2D) layered structures and extraordinary physicochemical properties. In order to broaden the range of potential applications, defect engineering is applied to the metastable phases of TMDs for further improvement of their catalytic and electronic properties. According to some recent studies, effective introduction of defects without perturbing the interior conductivity contributes to the development of metastable TMDs. This review provides deep insights into recent progress in electrochemistry using defect engineering in the metastable phases of TMDs. After introducing the structures of metastable phases and methods for defect construction, significant developments in catalysis and energy storage applications are discussed to elucidate structure-function relationships. Key challenges and future directions for defect engineering in the metastable phases of TMDs are also highlighted in the conclusions.
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Affiliation(s)
- Ran Wang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Jiecai Han
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Bo Yang
- China Institute of Marine Technology and Economy, Beijing, 100081, P. R. China
| | - Xianjie Wang
- Department of Physics, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Xinghong Zhang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Bo Song
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150001, P. R. China
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15
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Sukhanova EV, Kvashnin DG, Popov ZI. Induced spin polarization in graphene via interactions with halogen doped MoS 2 and MoSe 2 monolayers by DFT calculations. NANOSCALE 2020; 12:23248-23258. [PMID: 33206100 DOI: 10.1039/d0nr06287a] [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
Magnetic halogen doped MoX2 (X = S and Se) monolayers influenced the electronic structure of graphene through a proximity effect. This process was observed using state-of-the-art calculations. It was found that the substitution of a single chalcogen atom with a halogen atom (F, Cl, Br, and I) results in n-type doping of MoX2. An additional electron from the dopant is localized on binding orbitals with the nearest Mo atoms and leads to the formation of magnetism in the dichalcogenide layer. Detailed analysis of halogen doped MoX2/graphene heterostructures demonstrated the induction of spin polarization in graphene near the Fermi energy. Significant spin polarization near the Fermi energy and n-type doping were observed in the graphene layer of MoSe2/graphene heterostructures with MoSe2 doped with iodine. At the same time, fluorine-doped MoSe2 does not cause n-doping in graphene, while spin polarization still takes place. The possibility for the detection of the arrangement of the halogen impurities at the MoX2 basal plane even with the graphene layer deposited on top was demonstrated through STM measurements which will be undoubtedly useful for the fabrication of electronic schemes and elements based on the proposed heterostructures for their further application in nanoelectronics and spintronics.
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Affiliation(s)
- Ekaterina V Sukhanova
- Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny, Moscow Region, 141701, Russian Federation.
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Arnold AJ, Schulman DS, Das S. Thickness Trends of Electron and Hole Conduction and Contact Carrier Injection in Surface Charge Transfer Doped 2D Field Effect Transistors. ACS NANO 2020; 14:13557-13568. [PMID: 33026795 DOI: 10.1021/acsnano.0c05572] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
One of the main limiting factors in the performance of devices based on two-dimensional (2D) materials is Fermi level pinning at the contacts, which creates Schottky barriers (SBs) that increase contact resistance and, for most transition metal dichalcogenides (TMDs), limit hole conduction. A promising method to mitigate these problems is surface charge transfer doping (SCTD), which places fixed charge at the surface of the material and thins the SBs by locally shifting the energy bands. We use a mild O2 plasma to convert the top few layers of a given TMD into a substoichiometric oxide that serves as a p-type SCTD layer. A comprehensive experimental study, backed by TCAD simulations, involving MoS2, MoSe2, MoTe2, WS2, and WSe2 flakes of various thicknesses exposed to different plasma times is used to investigate the underlying mechanisms responsible for SCTD. The surface charge at the top of the channel and the gate-modulated surface potential at the bottom are found to have competing effects on the channel potential, which results in a decrease in the doping-induced threshold shift and an increase in minimum OFF state current with increasing thickness. Additionally, an undoped channel region is shown to mitigate carrier injection issues in sufficiently thin flakes. Notably, the band movements underlying the SCTD effects are independent of the particular semiconductor material, SCTD strategy, and doping polarity. Consequently, our findings provide critical insights for the design of high-performance transistors for a wide range of materials and SCTD mechanisms including TMD devices with strong hole conduction.
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Affiliation(s)
- Andrew J Arnold
- Department of Electrical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Daniel S Schulman
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Saptarshi Das
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802, United States
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17
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Zhao Y, Zheng M, Wu J, Huang B, Thong JTL. Studying thermal transport in suspended monolayer molybdenum disulfide prepared by a nano-manipulator-assisted transfer method. NANOTECHNOLOGY 2020; 31:225702. [PMID: 32053806 DOI: 10.1088/1361-6528/ab7647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The thermal transport of monolayer MoS2, grown by chemical vapor deposition (CVD) method, was studied in this work. A novel approach was developed to transfer monolayer MoS2 onto suspended microelectrothermal system device, where a nano-manipulator in a scanning electron microscope was employed to accomplish the feat. This nano-manipulator-assisted transferring gives a high sample yield with relatively good sample quality compared to the traditional wet/dry transfer methods. Temperature-dependent thermal conductivity of monolayer MoS2 was measured by suspended-pads thermal bridge technique, with thermal conductivity value slightly lower than the exfoliated samples due to the phonon-defects scattering for CVD grown samples. Further extension of the current transfer method was demonstrated on few-layer graphite, where suspended graphite flakes that were free of surface ripples and with high thermal conductance were shown.
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Affiliation(s)
- Yunshan Zhao
- Department of Electrical and Computer Engineering, National University of Singapore, 117583, Singapore
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18
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Lin YC, Liu C, Yu Y, Zarkadoula E, Yoon M, Puretzky AA, Liang L, Kong X, Gu Y, Strasser A, Meyer HM, Lorenz M, Chisholm MF, Ivanov IN, Rouleau CM, Duscher G, Xiao K, Geohegan DB. Low Energy Implantation into Transition-Metal Dichalcogenide Monolayers to Form Janus Structures. ACS NANO 2020; 14:3896-3906. [PMID: 32150384 DOI: 10.1021/acsnano.9b10196] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Atomically thin two-dimensional (2D) materials face significant energy barriers for synthesis and processing into functional metastable phases such as Janus structures. Here, the controllable implantation of hyperthermal species from pulsed laser deposition (PLD) plasmas is introduced as a top-down method to compositionally engineer 2D monolayers. The kinetic energies of Se clusters impinging on suspended monolayer WS2 crystals were controlled in the <10 eV/atom range with in situ plasma diagnostics to determine the thresholds for selective top layer replacement of sulfur by selenium for the formation of high quality WSSe Janus monolayers at low (300 °C) temperatures and bottom layer replacement for complete conversion to WSe2. Atomic-resolution electron microscopy and spectroscopy in tilted geometry confirm the WSSe Janus monolayer. Molecular dynamics simulations reveal that Se clusters implant to form disordered metastable alloy regions, which then recrystallize to form highly ordered structures, demonstrating low-energy implantation by PLD for the synthesis of 2D Janus layers and alloys of variable composition.
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Affiliation(s)
- Yu-Chuan Lin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Chenze Liu
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Yiling Yu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Eva Zarkadoula
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Mina Yoon
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Alexander A Puretzky
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Liangbo Liang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Xiangru Kong
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Yiyi Gu
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Alex Strasser
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77840, United States
| | - Harry M Meyer
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Matthias Lorenz
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Matthew F Chisholm
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Ilia N Ivanov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Christopher M Rouleau
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - Gerd Duscher
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Kai Xiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
| | - David B Geohegan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, United States
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Shawkat MS, Gil J, Han SS, Ko TJ, Wang M, Dev D, Kwon J, Lee GH, Oh KH, Chung HS, Roy T, Jung Y, Jung Y. Thickness-Independent Semiconducting-to-Metallic Conversion in Wafer-Scale Two-Dimensional PtSe 2 Layers by Plasma-Driven Chalcogen Defect Engineering. ACS APPLIED MATERIALS & INTERFACES 2020; 12:14341-14351. [PMID: 32124612 DOI: 10.1021/acsami.0c00116] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Platinum diselenide (PtSe2) is an emerging class of two-dimensional (2D) transition-metal dichalcogenide (TMD) crystals recently gaining substantial interest, owing to its extraordinary properties absent in conventional 2D TMD layers. Most interestingly, it exhibits a thickness-dependent semiconducting-to-metallic transition, i.e., thick 2D PtSe2 layers, which are intrinsically metallic, become semiconducting with their thickness reduced below a certain point. Realizing both semiconducting and metallic phases within identical 2D PtSe2 layers in a spatially well-controlled manner offers unprecedented opportunities toward atomically thin tailored electronic junctions, unattainable with conventional materials. In this study, beyond this thickness-dependent intrinsic semiconducting-to-metallic transition of 2D PtSe2 layers, we demonstrate that controlled plasma irradiation can "externally" achieve such tunable carrier transports. We grew wafer-scale very thin (a few nm) 2D PtSe2 layers by a chemical vapor deposition (CVD) method and confirmed their intrinsic semiconducting properties. We then irradiated the material with argon (Ar) plasma, which was intended to make it more semiconducting by thickness reduction. Surprisingly, we discovered a reversed transition of semiconducting to metallic, which is opposite to the prediction concerning their intrinsic thickness-dependent carrier transports. Through extensive structural and chemical characterization, we identified that the plasma irradiation introduces a large concentration of near-atomic defects and selenium (Se) vacancies in initially stoichiometric 2D PtSe2 layers. Furthermore, we performed density functional theory (DFT) calculations and clarified that the band-gap energy of such defective 2D PtSe2 layers gradually decreases with increasing defect concentration and dimensions, accompanying a large number of midgap energy states. This corroborative experimental and theoretical study decisively verifies the fundamental mechanism for this externally controlled semiconducting-to-metallic transition in large-area CVD-grown 2D PtSe2 layers, greatly broadening their versatility for futuristic electronics.
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Affiliation(s)
- Mashiyat Sumaiya Shawkat
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- Department of Electrical and Computer Engineering, University of Central Florida, Orlando, Florida 32816, United States
| | - Jaeyoung Gil
- Department of Chemistry, Seoul National University, Seoul 08826, South Korea
| | - Sang Sub Han
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, South Korea
| | - Tae-Jun Ko
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
| | - Mengjing Wang
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
| | - Durjoy Dev
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- Department of Electrical and Computer Engineering, University of Central Florida, Orlando, Florida 32816, United States
| | - Junyoung Kwon
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, South Korea
| | - Gwan-Hyoung Lee
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, South Korea
| | - Kyu Hwan Oh
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, South Korea
| | - Hee-Suk Chung
- Analytical Research Division, Korea Basic Science Institute, Jeonju 54907, South Korea
| | - Tania Roy
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- Department of Electrical and Computer Engineering, University of Central Florida, Orlando, Florida 32816, United States
- Department of Materials Science and Engineering, University of Central Florida, Orlando, Florida 32816, United States
| | - YounJoon Jung
- Department of Chemistry, Seoul National University, Seoul 08826, South Korea
| | - Yeonwoong Jung
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, United States
- Department of Electrical and Computer Engineering, University of Central Florida, Orlando, Florida 32816, United States
- Department of Materials Science and Engineering, University of Central Florida, Orlando, Florida 32816, United States
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20
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Singh A, Lee S, Bae H, Koo J, Yang L, Lee H. Theoretical investigation of the vertical dielectric screening dependence on defects for few-layered van der Waals materials. RSC Adv 2019; 9:40309-40315. [PMID: 35542649 PMCID: PMC9076166 DOI: 10.1039/c9ra07700f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/19/2019] [Indexed: 11/21/2022] Open
Abstract
First-principle calculations were employed to analyze the effects induced by vacancies of molybdenum (Mo) and sulfur (S) on the dielectric properties of few-layered MoS2. We explored the combined effects of vacancies and dipole interactions on the dielectric properties of few-layered MoS2. In the presence of dielectric screening, we investigated uniformly distributed Mo and S vacancies, and then considered the case of concentrated vacancies. Our results show that the dielectric screening remarkably depends on the distribution of vacancies owing to the polarization induced by the vacancies and on the interlayer distances. This conclusion was validated for a wide range of wide-gap semiconductors with different positions and distributions of vacancies, providing an effective and reliable method for calculating and predicting electrostatic screening of dimensionally reduced materials. We further provided a method for engineering the dielectric constant by changing the interlayer distance, tuning the number of vacancies and the distribution of vacancies in few-layered van der Waals materials for their application in nanodevices and supercapacitors.
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Affiliation(s)
- Amit Singh
- Department of Physics, Konkuk University Seoul 05029 Korea
- Department of Mechanical Engineering, National Chiao Tung University Hsinchu 300 Taiwan Republic of China
| | - Seunghan Lee
- Department of Physics, Konkuk University Seoul 05029 Korea
| | - Hyeonhu Bae
- Department of Physics, Konkuk University Seoul 05029 Korea
| | - Jahyun Koo
- Department of Condensed Matter Physics, Weizmann Institute of Science Rehovot 7610001 Israel
| | - Li Yang
- Department of Physics, Washington University in St. Louis St. Louis Missouri 63136 USA
| | - Hoonkyung Lee
- Department of Physics, Konkuk University Seoul 05029 Korea
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21
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Huang B, Zheng M, Zhao Y, Wu J, Thong JTL. Atomic Layer Deposition of High-Quality Al 2O 3 Thin Films on MoS 2 with Water Plasma Treatment. ACS APPLIED MATERIALS & INTERFACES 2019; 11:35438-35443. [PMID: 31476859 DOI: 10.1021/acsami.9b10940] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Atomic layer deposition (ALD) of ultrathin dielectric films on two-dimensional (2D) materials for electronic device applications remains one of the key challenges because of the lack of dangling bonds on the 2D material surface. In this work, a new technique to deposit uniform and high-quality Al2O3 films with thickness down to 1.5 nm on MoS2 is introduced. By treating the surface using water plasma prior to the ALD process, hydroxyl groups are introduced to the MoS2 surface, facilitating the chemisorption of trimethylaluminum in a conventional water-based ALD system. Raman and X-ray photoelectron spectroscopy measurements show that the water plasma treatment does not induce noticeable material degradation. The deposited Al2O3 films show excellent device-related electrical performance characteristics, including low interface trap density and outstanding gate controllability.
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Affiliation(s)
- Binjie Huang
- Department of Electrical and Computer Engineering , National University of Singapore , 117583 , Singapore
- NUS Graduate School for Integrative Sciences and Engineering , National University of Singapore , 119077 , Singapore
| | - Minrui Zheng
- Department of Electrical and Computer Engineering , National University of Singapore , 117583 , Singapore
| | - Yunshan Zhao
- Department of Electrical and Computer Engineering , National University of Singapore , 117583 , Singapore
| | - Jing Wu
- Institute of Materials Research and Engineering , Agency for Science Technology and Research , 138634 , Singapore
| | - John T L Thong
- Department of Electrical and Computer Engineering , National University of Singapore , 117583 , Singapore
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