1
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Pitters J, Croshaw J, Achal R, Livadaru L, Ng S, Lupoiu R, Chutora T, Huff T, Walus K, Wolkow RA. Atomically Precise Manufacturing of Silicon Electronics. ACS Nano 2024; 18:6766-6816. [PMID: 38376086 PMCID: PMC10919096 DOI: 10.1021/acsnano.3c10412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 02/21/2024]
Abstract
Atomically precise manufacturing (APM) is a key technique that involves the direct control of atoms in order to manufacture products or components of products. It has been developed most successfully using scanning probe methods and has received particular attention for developing atom scale electronics with a focus on silicon-based systems. This review captures the development of silicon atom-based electronics and is divided into several sections that will cover characterization and atom manipulation of silicon surfaces with scanning tunneling microscopy and atomic force microscopy, development of silicon dangling bonds as atomic quantum dots, creation of atom scale devices, and the wiring and packaging of those circuits. The review will also cover the advance of silicon dangling bond logic design and the progress of silicon quantum atomic designer (SiQAD) simulators. Finally, an outlook of APM and silicon atom electronics will be provided.
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Affiliation(s)
- Jason Pitters
- Nanotechnology
Research Centre, National Research Council
of Canada, Edmonton, Alberta T6G 2M9, Canada
| | - Jeremiah Croshaw
- Department
of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Roshan Achal
- Department
of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
- Quantum
Silicon Inc., Edmonton, Alberta T6G 2M9, Canada
| | - Lucian Livadaru
- Department
of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
- Quantum
Silicon Inc., Edmonton, Alberta T6G 2M9, Canada
| | - Samuel Ng
- Department
of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Robert Lupoiu
- School
of Engineering, Stanford University, Stanford, California 94305, United States
| | - Taras Chutora
- Department
of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Taleana Huff
- Canadian
Bank Note Company, Ottawa, Ontario K1Z 1A1, Canada
| | - Konrad Walus
- Department
of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Robert A. Wolkow
- Department
of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
- Quantum
Silicon Inc., Edmonton, Alberta T6G 2M9, Canada
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2
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Pavlova TV, Shevlyuga VM. PBr3 adsorption on a chlorinated Si(100) surface with mono- and bivacancies. J Chem Phys 2024; 160:054701. [PMID: 38299628 DOI: 10.1063/5.0185671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 01/11/2024] [Indexed: 02/02/2024] Open
Abstract
For the most precise incorporation of single impurities in silicon, which is utilized to create quantum devices, a monolayer of adatoms on the Si(100) surface and a dopant-containing molecule are used. Here, we studied the interaction of phosphorus tribromide with a chlorine monolayer with mono- and bivacancies using a scanning tunneling microscope (STM) at 77 K. The combination of different halogens in the molecule and the adsorbate layer enabled unambiguous identification of the structures after PBr3 dissociation on Si(100)-Cl. A Cl monolayer was exposed to PBr3 in the STM chamber, which allows us to compare the same surface areas before and after PBr3 adsorption. As a result of this comparison, we detected small changes in the chlorine layer and unraveled the molecular fragments filling mono- and bivacancies. Using density functional theory, we found that the phosphorus atom occupies a bridge position after dissociation of the PBr3 molecule, which primarily bonds with silicon in Cl bivacancies. These findings provide insight into the interaction of a dopant-containing molecule with an adsorbate monolayer on Si(100) and can be applied to improve the process of single impurity incorporation into silicon.
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Affiliation(s)
- T V Pavlova
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str. 38, 119991 Moscow, Russia
- HSE University, Myasnitskaya Str. 20, 101000 Moscow, Russia
| | - V M Shevlyuga
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str. 38, 119991 Moscow, Russia
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3
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Pavlova TV, Shevlyuga VM. Enhancing the reactivity of Si(100)-Cl toward PBr3 by charging Si dangling bonds. J Chem Phys 2023; 159:214701. [PMID: 38038208 DOI: 10.1063/5.0178757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023] Open
Abstract
The interaction of the PBr3 molecule with Si dangling bonds (DBs) on a chlorinated Si(100) surface was studied. The DBs were charged in a scanning tunneling microscope (STM) and then exposed to PBr3 directly in the STM chamber. Uncharged DBs rarely react with molecules. On the contrary, almost all positively charged DBs were filled with molecule fragments. As a result of the PBr3 interaction with the positively charged DB, the molecule dissociated into PBr2 and Br with the formation of a Si-Br bond and PBr2 desorption. These findings show that charged DBs significantly modify the reactivity of the surface toward PBr3. Additionally, we calculated PH3 adsorption on a Si(100)-2 × 1-H surface with DBs and found that the DB charge also has a significant impact. As a result, we demonstrated that the positively charged DB with a doubly unoccupied state enhances the adsorption of molecules with a lone pair of electrons.
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Affiliation(s)
- T V Pavlova
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov str. 38, 119991 Moscow, Russia
- HSE University, Myasnitskaya str. 20, 101000 Moscow, Russia
| | - V M Shevlyuga
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov str. 38, 119991 Moscow, Russia
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4
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Li T, Peiris CR, Aragonès AC, Hurtado C, Kicic A, Ciampi S, MacGregor M, Darwish T, Darwish N. Terminal Deuterium Atoms Protect Silicon from Oxidation. ACS Appl Mater Interfaces 2023; 15:47833-47844. [PMID: 37768872 DOI: 10.1021/acsami.3c11598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
In recent years, the hybrid silicon-molecular electronics technology has been gaining significant attention for applications in sensors, photovoltaics, power generation, and molecular electronics devices. However, Si-H surfaces, which are the platforms on which these devices are formed, are prone to oxidation, compromising the mechanical and electronic stability of the devices. Here, we show that when hydrogen is replaced by deuterium, the Si-D surface becomes significantly more resistant to oxidation when either positive or negative voltages are applied to the Si surface. Si-D surfaces are more resistant to oxidation, and their current-voltage characteristics are more stable than those measured on Si-H surfaces. At positive voltages, the Si-D stability appears to be related to the flat band potential of Si-D being more positive compared to Si-H surfaces, making Si-D surfaces less attractive to oxidizing OH- ions. The limited oxidation of Si-D surfaces at negative potentials is interpreted by the frequencies of the Si-D bending modes being coupled to that of the bulk Si surface phonon modes, which would make the duration of the Si-D excited vibrational state significantly less than that of Si-H. The strong surface isotope effect has implications in the design of silicon-based sensing, molecular electronics, and power-generation devices and the interpretation of charge transfer across them.
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Affiliation(s)
- Tiexin Li
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Chandramalika R Peiris
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Albert C Aragonès
- Departament de Ciència de Materials i Química Física, Universitat de Barcelona, Marti i Franquès 1, 08028 Barcelona, Spain
- Institut de Química Teòrica i Computacional (IQTC), Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Carlos Hurtado
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Anthony Kicic
- Occupation, Environment and Safety, School of Population Health, Curtin University, Bentley, Western Australia 6102, Australia
- Wal-Yan Respiratory Research Centre, Telethon Kids Institute, The University of Western Australia, Nedlands, Western Australia 6009, Australia
- Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, Western Australia 6009, Australia
- Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Melanie MacGregor
- Flinders Institute for Nanoscale Science & Technology, Flinders University, Bedford Park, South Australia 5042, Australia
| | - Tamim Darwish
- National Deuteration Facility, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, New South Wales 2234, Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
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5
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Liu Y, Li X, Pei B, Ge L, Xiong Z, Zhang Z. Towards smart scanning probe lithography: a framework accelerating nano-fabrication process with in-situ characterization via machine learning. Microsyst Nanoeng 2023; 9:128. [PMID: 37829156 PMCID: PMC10564742 DOI: 10.1038/s41378-023-00587-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/09/2023] [Accepted: 08/20/2023] [Indexed: 10/14/2023]
Abstract
Scanning probe lithography (SPL) is a promising technology to fabricate high-resolution, customized and cost-effective features at the nanoscale. However, the quality of nano-fabrication, particularly the critical dimension, is significantly influenced by various SPL fabrication techniques and their corresponding process parameters. Meanwhile, the identification and measurement of nano-fabrication features are very time-consuming and subjective. To tackle these challenges, we propose a novel framework for process parameter optimization and feature segmentation of SPL via machine learning (ML). Different from traditional SPL techniques that rely on manual labeling-based experimental methods, the proposed framework intelligently extracts reliable and global information for statistical analysis to fine-tune and optimize process parameters. Based on the proposed framework, we realized the processing of smaller critical dimensions through the optimization of process parameters, and performed direct-write nano-lithography on a large scale. Furthermore, data-driven feature extraction and analysis could potentially provide guidance for other characterization methods and fabrication quality optimization.
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Affiliation(s)
- Yijie Liu
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084 China
- Beijing Key Laboratory of Precision/Ultra-precision Manufacturing Equipments and Control, Tsinghua University, Beijing, 100084 China
| | - Xuexuan Li
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084 China
- Beijing Key Laboratory of Precision/Ultra-precision Manufacturing Equipments and Control, Tsinghua University, Beijing, 100084 China
| | - Ben Pei
- Biomanufacturing Center, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084 China
- Biomanufacturing and Rapid Forming Technology Key Laboratory of Beijing, Beijing, 100084 China
- ‘Biomanufacturing and Engineering Living Systems’ Innovation International Talents Base (111 Base), Beijing, 100084 China
| | - Lin Ge
- NT-MDT Spectrum Instruments China office, Beijing, 100053 China
| | - Zhuo Xiong
- Biomanufacturing Center, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084 China
- Biomanufacturing and Rapid Forming Technology Key Laboratory of Beijing, Beijing, 100084 China
- ‘Biomanufacturing and Engineering Living Systems’ Innovation International Talents Base (111 Base), Beijing, 100084 China
| | - Zhen Zhang
- State Key Laboratory of Tribology in Advanced Equipment, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084 China
- Beijing Key Laboratory of Precision/Ultra-precision Manufacturing Equipments and Control, Tsinghua University, Beijing, 100084 China
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6
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Pham VD, Dong C, Robinson JA. Atomic structures and interfacial engineering of ultrathin indium intercalated between graphene and a SiC substrate. Nanoscale Adv 2023; 5:5601-5612. [PMID: 37822905 PMCID: PMC10563832 DOI: 10.1039/d3na00630a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 09/07/2023] [Indexed: 10/13/2023]
Abstract
Two-dimensional metals stabilized at the interface between graphene and SiC are attracting considerable interest thanks to their intriguing physical properties, providing promising material platforms for quantum technologies. However, the nanoscale picture of the ultrathin metals within the interface that represents their ultimate two-dimensional limit has not been well captured. In this work, we explore the atomic structures and electronic properties of atomically thin indium intercalated at the epitaxial graphene/SiC interface by means of cryogenic scanning tunneling microscopy. Two types of surfaces with distinctive crystalline characteristics are found: (i) a triangular indium arrangement epitaxially matching the (√3 × √3)R30° cell of the SiC substrate and (ii) a featureless surface of more complex atomic structures. Local tunneling spectroscopy reveals a varying n-type doping in the graphene capping layer induced by the intercalated indium and an occupied electronic state at ∼-1.1 eV that is attributed to the electronic structure of the newly formed interface. Tip-induced surface manipulation is used to alter the interfacial landscape; indium atoms are locally de-intercalated below graphene. This enables the quantitative measurement of the intercalation thickness revealing mono and bi-atomic layer indium within the interface and offers the capability to tune the number of metal layers such that a monolayer is converted irreversibly to a bilayer indium. Our findings demonstrate a scanning probe-based method for in-depth investigation of ultrathin metal at the atomic level, holding importance from both fundamental and technical viewpoints.
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Affiliation(s)
- Van Dong Pham
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V. Hausvogteiplatz 5-7 10117 Berlin Germany
| | - Chengye Dong
- 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park PA USA
- Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park PA USA
| | - Joshua A Robinson
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park PA USA
- Center for Nanoscale Science, The Pennsylvania State University, University Park PA USA
- Department of Physics, The Pennsylvania State University, University Park PA USA
- 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park PA USA
- Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park PA USA
- Materials Research Institute, The Pennsylvania State University, University Park PA USA
- Department of Chemistry, The Pennsylvania State University, University Park PA USA
- Center for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park PA USA
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7
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Lei Y, Zhang T, Lin YC, Granzier-Nakajima T, Bepete G, Kowalczyk DA, Lin Z, Zhou D, Schranghamer TF, Dodda A, Sebastian A, Chen Y, Liu Y, Pourtois G, Kempa TJ, Schuler B, Edmonds MT, Quek SY, Wurstbauer U, Wu SM, Glavin NR, Das S, Dash SP, Redwing JM, Robinson JA, Terrones M. Graphene and Beyond: Recent Advances in Two-Dimensional Materials Synthesis, Properties, and Devices. ACS Nanosci Au 2022; 2:450-485. [PMID: 36573124 PMCID: PMC9782807 DOI: 10.1021/acsnanoscienceau.2c00017] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 12/30/2022]
Abstract
Since the isolation of graphene in 2004, two-dimensional (2D) materials research has rapidly evolved into an entire subdiscipline in the physical sciences with a wide range of emergent applications. The unique 2D structure offers an open canvas to tailor and functionalize 2D materials through layer number, defects, morphology, moiré pattern, strain, and other control knobs. Through this review, we aim to highlight the most recent discoveries in the following topics: theory-guided synthesis for enhanced control of 2D morphologies, quality, yield, as well as insights toward novel 2D materials; defect engineering to control and understand the role of various defects, including in situ and ex situ methods; and properties and applications that are related to moiré engineering, strain engineering, and artificial intelligence. Finally, we also provide our perspective on the challenges and opportunities in this fascinating field.
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Affiliation(s)
- Yu Lei
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Institute
of Materials Research, Tsinghua Shenzhen
International Graduate School, Shenzhen, Guangdong 518055, China,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Tianyi Zhang
- Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Yu-Chuan Lin
- Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Tomotaroh Granzier-Nakajima
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - George Bepete
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Dorota A. Kowalczyk
- Department
of Solid State Physics, Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, Lodz 90-236, Poland
| | - Zhong Lin
- Department
of Physics, University of Washington, Seattle, Washington 98195, United States
| | - Da Zhou
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Thomas F. Schranghamer
- Department
of Engineering Science and Mechanics, Pennsylvania
State University, University Park, Pennsylvania 16802, United States
| | - Akhil Dodda
- Department
of Engineering Science and Mechanics, 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
| | - Yifeng Chen
- Department
of Materials Science and Engineering, National
University of Singapore, 9 Engineering Drive, Singapore 117456, Singapore
| | - Yuanyue Liu
- Texas
Materials Institute and Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | | | - Thomas J. Kempa
- Department
of Chemistry, Johns Hopkins University, Baltimore, Maryland 21287, United States
| | - Bruno Schuler
- nanotech@surfaces
Laboratory, Empa − Swiss Federal
Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Mark T. Edmonds
- School
of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
| | - Su Ying Quek
- Department
of Materials Science and Engineering, National
University of Singapore, 9 Engineering Drive, Singapore 117456, Singapore
| | - Ursula Wurstbauer
- Institute
of Physics, University of Münster, Wilhelm-Klemm-Str. 10, Münster 48149, Germany
| | - Stephen M. Wu
- Department
of Electrical and Computer Engineering & Department of Physics
and Astronomy, University of Rochester, Rochester, New York 14627, United States
| | - Nicholas R. Glavin
- Air
Force
Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Dayton, Ohio 45433, United States
| | - Saptarshi Das
- Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Engineering Science and Mechanics, Pennsylvania
State University, University Park, Pennsylvania 16802, United States
| | - Saroj Prasad Dash
- Department
of Microtechnology and Nanoscience, Chalmers
University of Technology, Göteborg SE-412 96, Sweden
| | - Joan M. Redwing
- Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Joshua A. Robinson
- Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States,
| | - Mauricio Terrones
- Department
of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for Atomically Thin Multifunctional Coatings, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Center
for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Material Science and Engineering, The
Pennsylvania State University, University Park, Pennsylvania 16802, United States,Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States,Research
Initiative for Supra-Materials and Global Aqua Innovation Center, Shinshu University, 4-17-1Wakasato, Nagano 380-8553, Japan,
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8
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Wang X, Khatami E, Fei F, Wyrick J, Namboodiri P, Kashid R, Rigosi AF, Bryant G, Silver R. Experimental realization of an extended Fermi-Hubbard model using a 2D lattice of dopant-based quantum dots. Nat Commun 2022; 13:6824. [PMID: 36369280 PMCID: PMC9652469 DOI: 10.1038/s41467-022-34220-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 10/14/2022] [Indexed: 11/13/2022] Open
Abstract
The Hubbard model is an essential tool for understanding many-body physics in condensed matter systems. Artificial lattices of dopants in silicon are a promising method for the analog quantum simulation of extended Fermi-Hubbard Hamiltonians in the strong interaction regime. However, complex atom-based device fabrication requirements have meant emulating a tunable two-dimensional Fermi-Hubbard Hamiltonian in silicon has not been achieved. Here, we fabricate 3 × 3 arrays of single/few-dopant quantum dots with finite disorder and demonstrate tuning of the electron ensemble using gates and probe the many-body states using quantum transport measurements. By controlling the lattice constants, we tune the hopping amplitude and long-range interactions and observe the finite-size analogue of a transition from metallic to Mott insulating behavior. We simulate thermally activated hopping and Hubbard band formation using increased temperatures. As atomically precise fabrication continues to improve, these results enable a new class of engineered artificial lattices to simulate interactive fermionic models. Atomically precise artificial lattices of dopant-based quantum dots offer a tunable platform for simulations of interacting fermionic models. By leveraging advances in fabrication and atomic-state control, Wang et al. report quantum simulations of the 2D Fermi-Hubbard model on a 3 × 3 few-dopant quantum dot array.
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9
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Lee SW, Jeon B, Lee H, Park JY. Hot Electron Phenomena at Solid-Liquid Interfaces. J Phys Chem Lett 2022; 13:9435-9448. [PMID: 36194546 DOI: 10.1021/acs.jpclett.2c02319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Understanding the role of energy dissipation and charge transfer under exothermic chemical reactions on metal catalyst surfaces is important for elucidating the fundamental phenomena at solid-gas and solid-liquid interfaces. Recently, many surface chemistry studies have been conducted on the solid-liquid interface, so correlating electronic excitation in the liquid-phase with the reaction mechanism plays a crucial role in heterogeneous catalysis. In this review, we introduce the detection principle of electron transfer at the solid-liquid interface by developing cutting-edge technologies with metal-semiconductor Schottky nanodiodes. The kinetics of hot electron excitation are well correlated with the reaction rates, demonstrating that the operando method for understanding nonadiabatic interactions is helpful in studying the reaction mechanism of surface molecular processes. In addition to the detection of hot electrons excited by a catalytic reaction, we highlight recent results on how the transfer of the hot electrons influences surface chemical and photoelectrochemical reactions.
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Affiliation(s)
- Si Woo Lee
- Department of Chemistry Education, Korea National University of Education (KNUE), Chungbuk28173, Republic of Korea
| | - Beomjoon Jeon
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon34141, Republic of Korea
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon34141, Republic of Korea
| | - Hyosun Lee
- Department of Materials Science and Engineering, University of Seoul, Seoul04066, Republic of Korea
| | - Jeong Young Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon34141, Republic of Korea
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon34141, Republic of Korea
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10
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Abstract
Vibrational dynamics of adsorbates near surfaces plays both an important role for applied surface science and as model lab for studying fundamental problems of open quantum systems. We employ a previously developed model for the relaxation of a D-Si-Si bending mode at a D:Si(100)-(2$\times$1) surface, induced by a ``bath' of more than $2000$ phonon modes [U. Lorenz, P. Saalfrank, Chem. Phys. {\bf 482}, 69 (2017)], to extend previous work along various directions. First, we use a Hierarchical Effective Mode (HEM) model [E.W. Fischer, F. Bouakline, M. Werther, P. Saalfrank, J. Chem. Phys. {\bf 153}, 064704 (2020)] to study relaxation of higher excited vibrational states than hitherto done, by solving a high-dimensional system-bath time-dependent Schr\"odinger equation (TDSE). In the HEM approach, (many) real bath modes are replaced by (much less) effective bath modes. Accordingly, we are able to examine scaling laws for vibrational relaxation lifetimes for a realistic surface science problem. Second, we compare the performance of the multilayer multiconfigurational time-dependent Hartree (ML-MCTDH) approach with the recently developed coherent-state based multi-Davydov D2 {\it ansatz} [N. Zhou, Z. Huang, J. Zhu, V. Chernyak, Y. Zhao, {J. Chem. Phys.} {\bf 143}, 014113 (2015)]. Both approaches work well, with some computational advantages for the latter in the presented context. Third, we apply open-system density matrix theory in comparison with basically ``exact' solutions of the multi-mode TDSEs. Specifically, we use an open-system Liouville-von Neumann (LvN) equation treating vibration-phonon coupling as Markovian dissipation in Lindblad form to quantify effects beyond the Born-Markov approximation.
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Affiliation(s)
| | | | - Foudhil Bouakline
- Institute of Chemistry, Universität Potsdam Institut für Chemie, Germany
| | - Frank Grossmann
- Institute for Theoretical Physics, Technische Universität Dresden Fachrichtung Physik, Germany
| | - Peter Saalfrank
- Institut für Chemie, Universität Potsdam Institut für Chemie, Germany
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11
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Cochrane KA, Lee JH, Kastl C, Haber JB, Zhang T, Kozhakhmetov A, Robinson JA, Terrones M, Repp J, Neaton JB, Weber-Bargioni A, Schuler B. Spin-dependent vibronic response of a carbon radical ion in two-dimensional WS 2. Nat Commun 2021; 12:7287. [PMID: 34911952 PMCID: PMC8674275 DOI: 10.1038/s41467-021-27585-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 11/22/2021] [Indexed: 11/29/2022] Open
Abstract
Atomic spin centers in 2D materials are a highly anticipated building block for quantum technologies. Here, we demonstrate the creation of an effective spin-1/2 system via the atomically controlled generation of magnetic carbon radical ions (CRIs) in synthetic two-dimensional transition metal dichalcogenides. Hydrogenated carbon impurities located at chalcogen sites introduced by chemical doping are activated with atomic precision by hydrogen depassivation using a scanning probe tip. In its anionic state, the carbon impurity is computed to have a magnetic moment of 1 μB resulting from an unpaired electron populating a spin-polarized in-gap orbital. We show that the CRI defect states couple to a small number of local vibrational modes. The vibronic coupling strength critically depends on the spin state and differs for monolayer and bilayer WS2. The carbon radical ion is a surface-bound atomic defect that can be selectively introduced, features a well-understood vibronic spectrum, and is charge state controlled. Spin-polarized defects in 2D materials are attracting attention for future quantum technology applications, but their controlled fabrication is still challenging. Here, the authors report the creation and characterization of effective spin 1/2 defects via the atomically-precise generation of magnetic carbon radical ions in 2D WS2.
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Affiliation(s)
- Katherine A Cochrane
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jun-Ho Lee
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Christoph Kastl
- Walter-Schottky-Institut and Physik-Department, Technical University of Munich, Garching, 85748, Germany
| | - Jonah B Haber
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Tianyi Zhang
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16082, USA.,Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Azimkhan Kozhakhmetov
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16082, USA
| | - Joshua A Robinson
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16082, USA.,Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Mauricio Terrones
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16082, USA.,Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, PA, 16802, USA.,Department of Physics and Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Jascha Repp
- Institute of Experimental and Applied Physics, University of Regensburg, Regensburg, 93040, Germany
| | - Jeffrey B Neaton
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. .,Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA. .,Kavli Energy Nanosciences Institute at Berkeley, Berkeley, CA, 94720, USA.
| | | | - Bruno Schuler
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. .,nanotech@surfaces Laboratory, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, 8600, Switzerland.
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12
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Donnelly MB, Keizer JG, Chung Y, Simmons MY. Monolithic Three-Dimensional Tuning of an Atomically Defined Silicon Tunnel Junction. Nano Lett 2021; 21:10092-10098. [PMID: 34797661 DOI: 10.1021/acs.nanolett.1c03879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A requirement for quantum information processors is the in situ tunability of the tunnel rates and the exchange interaction energy within the device. The large energy level separation for atom qubits in silicon is well suited for qubit operation but limits device tunability using in-plane gate architectures, requiring vertically separated top-gates to control tunnelling within the device. In this paper, we address control of the simplest tunnelling device in Si:P, the tunnel junction. Here we demonstrate that we can tune its conductance by using a vertically separated top-gate aligned with ±5 nm precision to the junction. We show that a monolithic 3D epitaxial top-gate increases the capacitive coupling by a factor of 3 compared to in-plane gates, resulting in a tunnel barrier height tunability of 0-186 meV. By combining multiple gated junctions in series we extend our monolithic 3D gating technology to implement nanoscale logic circuits including AND and OR gates.
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Affiliation(s)
- Matthew B Donnelly
- Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney 2052, New South Wales, Australia
| | - Joris G Keizer
- Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney 2052, New South Wales, Australia
| | - Yousun Chung
- Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney 2052, New South Wales, Australia
| | - Michelle Y Simmons
- Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney 2052, New South Wales, Australia
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13
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Stone I, Starr RL, Zang Y, Nuckolls C, Steigerwald ML, Lambert TH, Roy X, Venkataraman L. A single-molecule blueprint for synthesis. Nat Rev Chem 2021; 5:695-710. [PMID: 37118183 DOI: 10.1038/s41570-021-00316-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2021] [Indexed: 11/08/2022]
Abstract
Chemical reactions that occur at nanostructured electrodes have garnered widespread interest because of their potential applications in fields including nanotechnology, green chemistry and fundamental physical organic chemistry. Much of our present understanding of these reactions comes from probes that interrogate ensembles of molecules undergoing various stages of the transformation concurrently. Exquisite control over single-molecule reactivity lets us construct new molecules and further our understanding of nanoscale chemical phenomena. We can study single molecules using instruments such as the scanning tunnelling microscope, which can additionally be part of a mechanically controlled break junction. These are unique tools that can offer a high level of detail. They probe the electronic conductance of individual molecules and catalyse chemical reactions by establishing environments with reactive metal sites on nanoscale electrodes. This Review describes how chemical reactions involving bond cleavage and formation can be triggered at nanoscale electrodes and studied one molecule at a time.
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14
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Frederick E, Dwyer KJ, Wang GT, Misra S, Butera RE. The stability of Cl-, Br-, and I-passivated Si(100)-(2 × 1) in ambient environments for atomically-precise pattern preservation. J Phys Condens Matter 2021; 33:444001. [PMID: 34348242 DOI: 10.1088/1361-648x/ac1aa4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
Atomic precision advanced manufacturing (APAM) leverages the highly reactive nature of Si dangling bonds relative to H- or Cl-passivated Si to selectively adsorb precursor molecules into lithographically defined areas with sub-nanometer resolution. Due to the high reactivity of dangling bonds, this process is confined to ultra-high vacuum (UHV) environments, which currently limits its commercialization and broad-based appeal. In this work, we explore the use of halogen adatoms to preserve APAM-derived lithographic patterns outside of UHV to enable facile transfer into real-world commercial processes. Specifically, we examine the stability of H-, Cl-, Br-, and I-passivated Si(100) in inert N2and ambient environments. Characterization with scanning tunneling microscopy and x-ray photoelectron spectroscopy (XPS) confirmed that each of the fully passivated surfaces were resistant to oxidation in 1 atm of N2for up to 44 h. Varying levels of surface degradation and contamination were observed upon exposure to the laboratory ambient environment. Characterization byex situXPS after ambient exposures ranging from 15 min to 8 h indicated the Br- and I-passivated Si surfaces were highly resistant to degradation, while Cl-passivated Si showed signs of oxidation within minutes of ambient exposure. As a proof-of-principle demonstration of pattern preservation, a H-passivated Si sample patterned and passivated with independent Cl, Br, I, and bare Si regions was shown to maintain its integrity in all but the bare Si region post-exposure to an N2environment. The successful demonstration of the preservation of APAM patterns outside of UHV environments opens new possibilities for transporting atomically-precise devices outside of UHV for integrating with non-UHV processes, such as other chemistries and commercial semiconductor device processes.
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Affiliation(s)
- E Frederick
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
| | - K J Dwyer
- Department of Physics, University of Maryland, College Park, MD 20742, United States of America
| | - G T Wang
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
| | - S Misra
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
| | - R E Butera
- Laboratory for Physical Sciences, 8050 Greenmead Drive, College Park, MD 20740, United States of America
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15
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Wang Y, Wemhoff PI, Lewandowski M, Nilius N. Electron stimulated desorption of vanadyl-groups from vanadium oxide thin films on Ru(0001) probed with STM. Phys Chem Chem Phys 2021; 23:8439-8445. [PMID: 33876007 DOI: 10.1039/d0cp06419j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Low-temperature scanning tunnelling microscopy (STM) is employed to study electron-stimulated desorption of vanadyl groups from an ultrathin vanadium oxide film. The vanadia patches are prepared by reactive vapour deposition of V onto a Ru(0001) surface and comprise a highly ordered network of six and twelve membered V-O rings, some of them terminated by upright V[double bond, length as m-dash]O groups. The vanadyl units can be desorbed via electron injection from the STM tip in a reliable fashion. From hundreds of individual experiments, desorption rates are determined as a function of bias voltage and tunnelling current. Data analysis reveals a distinct threshold behaviour with bias onsets at +3.3 V and -2.6 V for positive and negative polarity, respectively. The desorption rate varies quadratically (cubically) with the tunnelling current at positive (negative) sample bias, indicating that V[double bond, length as m-dash]O desorption is a many-electron process. Based on our findings, a mechanism for desorption is proposed that includes resonant tunnelling into anti-bonding or out of bonding orbitals, followed by vibrational ladder climbing in the binding potential of the V[double bond, length as m-dash]O ad-system. The underlying electronic states can be identified directly in the STM conductance spectra taken on the oxide surface.
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Affiliation(s)
- Ying Wang
- Carl von Ossietzky Universität Oldenburg, Institut für Physik, D-26111 Oldenburg, Germany.
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16
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Kaku S, Yoshino J. Temperature-Dependent Tip-Induced Motion of Ga Adatom on GaAs (110) Surface. Small 2020; 16:e2002296. [PMID: 32614477 DOI: 10.1002/smll.202002296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/30/2020] [Indexed: 06/11/2023]
Abstract
The temperature-dependent tip-induced-motion of a Ga adatom on a GaAs (110) surface is experimentally demonstrated using scanning tunneling microscopy (STM). The surface adsorption energy profile obtained by first-principle electronic structure calculations reveals that the origin of the Ga motion observed at 78 K is attributable to the tip-induced Ga adatom hopping between the most stable potential minima among the three local minima, whereas that observed at 4.2 K is attributable to the tip-induced hopping and sliding motions through the next stable minima as well as the most stable minima. Furthermore, it is shown that a slight progressive modification of the adatom motion observed only at 4.2 K resulting from repeated STM line scans is consistent with the overall picture taking account of the heating of the adatom owing to the tip current.
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Affiliation(s)
- Shigeru Kaku
- Department of Physics, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Junji Yoshino
- Department of Physics, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
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17
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Tchalala MR, Enriquez H, Bendounan A, Mayne AJ, Dujardin G, Kara A, Ali MA, Oughaddou H. Tip-induced oxidation of silicene nano-ribbons. Nanoscale Adv 2020; 2:2309-2314. [PMID: 36133383 PMCID: PMC9419031 DOI: 10.1039/d0na00332h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 05/12/2020] [Indexed: 06/16/2023]
Abstract
We report on the oxidation of self-assembled silicene nanoribbons grown on the Ag (110) surface using scanning tunneling microscopy and high-resolution photoemission spectroscopy. The results show that silicene nanoribbons present a strong resistance towards oxidation using molecular oxygen. This can be overcome by increasing the electric field in the STM tunnel junction above a threshold of +2.6 V to induce oxygen dissociation and reaction. The higher reactivity of the silicene nanoribbons towards atomic oxygen is observed as expected. The HR-PES confirm these observations: even at high exposures of molecular oxygen, the Si 2p core-level peaks corresponding to pristine silicene remain dominant, reflecting a very low reactivity to molecular oxygen. Complete oxidation is obtained following exposure to high doses of atomic oxygen; the Si 2p core level peak corresponding to pristine silicene disappears.
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Affiliation(s)
- Mohamed Rachid Tchalala
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO) Bât. 520 91405 Orsay France
| | - Hanna Enriquez
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO) Bât. 520 91405 Orsay France
| | - Azzedine Bendounan
- Synchrotron Soleil L'Orme des Merisiers Saint-Aubin, B.P. 48 91192 Gif-sur-Yvette Cedex France
| | - Andrew J Mayne
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO) Bât. 520 91405 Orsay France
| | - Gérald Dujardin
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO) Bât. 520 91405 Orsay France
| | - Abdelkader Kara
- Department of Physics, University of Central Florida Orlando FL 32816 USA
| | - Mustapha Ait Ali
- Laboratoire de Chimie de Coordination et Catalyse, Département de Chimie, Faculté des Sciences-Semlalia, Université Cadi Ayyad Marrakech 40001 Morocco
| | - Hamid Oughaddou
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO) Bât. 520 91405 Orsay France
- Département de Physique, Université de Cergy-Pontoise 95031 Cergy-Pontoise Cedex France
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18
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Gordon OM, Moriarty PJ. Machine learning at the (sub)atomic scale: next generation scanning probe microscopy. Mach Learn : Sci Technol 2020. [DOI: 10.1088/2632-2153/ab7d2f] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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19
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Gordon OM, Junqueira FLQ, Moriarty PJ. Embedding human heuristics in machine-learning-enabled probe microscopy. Mach Learn : Sci Technol 2020. [DOI: 10.1088/2632-2153/ab42ec] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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20
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Abstract
Single-atom manipulation within doped correlated electron systems could help disentangle the influence of dopants, structural defects, and crystallographic characteristics on local electronic states. Unfortunately, the high diffusion barrier in these materials prevents conventional manipulation techniques. Here, we demonstrate the possibility to reversibly manipulate select sites in the optimally doped high-temperature superconductor Bi2Sr2CaCu2O8+x using the local electric field of the tip of a scanning tunneling microscope. We show that upon shifting individual Bi atoms at the surface, the spectral gap associated with superconductivity is seen to reversibly change by as much as 15 milli-electron volts (on average ~5% of the total gap size). Our toy model, which captures all observed characteristics, suggests that the electric field induces lateral movement of local pairing potentials in the CuO2 plane.
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Affiliation(s)
- F Massee
- Laboratoire de Physique des Solides, CNRS UMR 8502, Bâtiment 510, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France.
| | - Y K Huang
- Institute of Physics, University of Amsterdam, 1098XH Amsterdam, Netherlands
| | - M Aprili
- Laboratoire de Physique des Solides, CNRS UMR 8502, Bâtiment 510, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
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21
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Wang C, Chi L, Ciesielski A, Samorì P. Chemische Synthese an Oberflächen mit Präzision in atomarer Größenordnung: Beherrschung von Komplexität und Genauigkeit. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201906645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Can Wang
- Université de Strasbourg CNRS ISIS 8 alleé Gaspard Monge 67000 Strasbourg France
| | - Lifeng Chi
- Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon Based Functional Materials & Devices Soochow University Suzhou 215123 V.R. China
| | - Artur Ciesielski
- Université de Strasbourg CNRS ISIS 8 alleé Gaspard Monge 67000 Strasbourg France
| | - Paolo Samorì
- Université de Strasbourg CNRS ISIS 8 alleé Gaspard Monge 67000 Strasbourg France
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22
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Wang C, Chi L, Ciesielski A, Samorì P. Chemical Synthesis at Surfaces with Atomic Precision: Taming Complexity and Perfection. Angew Chem Int Ed Engl 2019; 58:18758-18775. [DOI: 10.1002/anie.201906645] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/25/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Can Wang
- Université de StrasbourgCNRSISIS 8 alleé Gaspard Monge 67000 Strasbourg France
| | - Lifeng Chi
- Institute of Functional Nano & Soft Materials (FUNSOM)Jiangsu Key Laboratory for Carbon Based Functional, Materials & DevicesSoochow University Suzhou 215123 P. R. China
| | - Artur Ciesielski
- Université de StrasbourgCNRSISIS 8 alleé Gaspard Monge 67000 Strasbourg France
| | - Paolo Samorì
- Université de StrasbourgCNRSISIS 8 alleé Gaspard Monge 67000 Strasbourg France
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23
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Affiliation(s)
- K. J. Dwyer
- Department of Physics, University of Maryland, College Park, Maryland 20740, United States
| | - Michael Dreyer
- Department of Physics, University of Maryland, College Park, Maryland 20740, United States
| | - R. E. Butera
- Laboratory for Physical Sciences, 8050 Greenmead Drive, College Park, Maryland 20740, United States
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24
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Aso R, Ogawa Y, Tamaoka T, Yoshida H, Takeda S. Visualizing Progressive Atomic Change in the Metal Surface Structure Made by Ultrafast Electronic Interactions in an Ambient Environment. Angew Chem Int Ed Engl 2019; 58:16028-16032. [PMID: 31486177 DOI: 10.1002/anie.201907679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/28/2019] [Indexed: 11/07/2022]
Abstract
Understanding the atomic and molecular phenomena occurring in working catalysts and nanodevices requires the elucidation of atomic migration originating from electronic excitations. The progressive atomic dynamics on metal surface under controlled electronic stimulus in real time, space, and gas environments are visualized for the first time. By in situ environmental transmission electron microscopy, the gas molecules introduced into the biased metal nanogap could be activated by electron tunneling and caused the unpredicted atomic dynamics. The typically inactive gold was oxidized locally on the positive tip and field-evaporated to the negative tip, resulting in the atomic reconstruction on the negative tip surface. This finding of a tunneling-electron-attached-gas process will bring new insights into the design of nanostructures such as nanoparticle catalysts and quantum nanodots and will stimulate syntheses of novel nanomaterials not seen in the ambient environment.
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Affiliation(s)
- Ryotaro Aso
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
| | - Yohei Ogawa
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
- Department of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takehiro Tamaoka
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
- Department of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hideto Yoshida
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
| | - Seiji Takeda
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
- Institute for NanoScience Design, Osaka University, 1-3 machikaneyama, Toyonaka, Osaka, 560-8531, Japan
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25
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Aso R, Ogawa Y, Tamaoka T, Yoshida H, Takeda S. Visualizing Progressive Atomic Change in the Metal Surface Structure Made by Ultrafast Electronic Interactions in an Ambient Environment. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201907679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ryotaro Aso
- The Institute of Scientific and Industrial ResearchOsaka University 8-1 Mihogaoka, Ibaraki Osaka 567-0047 Japan
| | - Yohei Ogawa
- The Institute of Scientific and Industrial ResearchOsaka University 8-1 Mihogaoka, Ibaraki Osaka 567-0047 Japan
- Department of Materials and Manufacturing ScienceGraduate School of EngineeringOsaka University 2-1 Yamadaoka, Suita Osaka 565-0871 Japan
| | - Takehiro Tamaoka
- The Institute of Scientific and Industrial ResearchOsaka University 8-1 Mihogaoka, Ibaraki Osaka 567-0047 Japan
- Department of Materials and Manufacturing ScienceGraduate School of EngineeringOsaka University 2-1 Yamadaoka, Suita Osaka 565-0871 Japan
| | - Hideto Yoshida
- The Institute of Scientific and Industrial ResearchOsaka University 8-1 Mihogaoka, Ibaraki Osaka 567-0047 Japan
| | - Seiji Takeda
- The Institute of Scientific and Industrial ResearchOsaka University 8-1 Mihogaoka, Ibaraki Osaka 567-0047 Japan
- Institute for NanoScience DesignOsaka University 1–3 machikaneyama, Toyonaka Osaka 560-8531 Japan
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26
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Huff TR, Dienel T, Rashidi M, Achal R, Livadaru L, Croshaw J, Wolkow RA. Electrostatic Landscape of a Hydrogen-Terminated Silicon Surface Probed by a Moveable Quantum Dot. ACS Nano 2019; 13:10566-10575. [PMID: 31386340 DOI: 10.1021/acsnano.9b04653] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
With nanoelectronics reaching the limit of atom-sized devices, it has become critical to examine how irregularities in the local environment can affect device functionality. Here, we characterize the influence of charged atomic species on the electrostatic potential of a semiconductor surface at the subnanometer scale. Using noncontact atomic force microscopy, two-dimensional maps of the contact potential difference are used to show the spatially varying electrostatic potential on the (100) surface of hydrogen-terminated highly doped silicon. Three types of charged species, one on the surface and two within the bulk, are examined. An electric field sensitive spectroscopic signature of a single probe atom reports on nearby charged species. The identity of one of the near-surface species has been uncertain in the literature, and we suggest that its character is more consistent with either a negatively charged interstitial hydrogen or a hydrogen vacancy complex.
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Affiliation(s)
- Taleana R Huff
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
- Quantum Silicon, Inc. , Edmonton , Alberta T6G 2M9 , Canada
| | - Thomas Dienel
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
| | - Mohammad Rashidi
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
| | - Roshan Achal
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
- Quantum Silicon, Inc. , Edmonton , Alberta T6G 2M9 , Canada
| | | | - Jeremiah Croshaw
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
| | - Robert A Wolkow
- Department of Physics , University of Alberta , Edmonton , Alberta T6G 2J1 , Canada
- Nanotechnology Research Centre , National Research Council Canada , Edmonton , Alberta T6G 2M9 , Canada
- Quantum Silicon, Inc. , Edmonton , Alberta T6G 2M9 , Canada
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27
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Jia P, Chen W, Qiao J, Zhang M, Zheng X, Xue Z, Liang R, Tian C, He L, Di Z, Wang X. Programmable graphene nanobubbles with three-fold symmetric pseudo-magnetic fields. Nat Commun 2019; 10:3127. [PMID: 31311927 PMCID: PMC6635427 DOI: 10.1038/s41467-019-11038-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 06/11/2019] [Indexed: 11/09/2022] Open
Abstract
Graphene nanobubbles (GNBs) have attracted much attention due to the ability to generate large pseudo-magnetic fields unattainable by ordinary laboratory magnets. However, GNBs are always randomly produced by the reported protocols, therefore, their size and location are difficult to manipulate, which restricts their potential applications. Here, using the functional atomic force microscopy (AFM), we demonstrate the ability to form programmable GNBs. The precision of AFM facilitates the location definition of GNBs, and their size and shape are tuned by the stimulus bias of AFM tip. With tuning the tip voltage, the bubble contour can gradually transit from parabolic to Gaussian profile. Moreover, the unique three-fold symmetric pseudo-magnetic field pattern with monotonous regularity, which is only theoretically predicted previously, is directly observed in the GNB with an approximately parabolic profile. Our study may provide an opportunity to study high magnetic field regimes with the designed periodicity in two dimensional materials.
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Affiliation(s)
- Pengfei Jia
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Wenjing Chen
- The Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, 100875, Beijing, China
| | - Jiabin Qiao
- The Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, 100875, Beijing, China
| | - Miao Zhang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Xiaohu Zheng
- International Center for Quantum Materials, Peking University, 100871, Beijing, China
| | - Zhongying Xue
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Rongda Liang
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro- and Nano-Photonic Structure (MOE), Fudan University, 200433, Shanghai, China
| | - Chuanshan Tian
- Department of Physics, State Key Laboratory of Surface Physics and Key Laboratory of Micro- and Nano-Photonic Structure (MOE), Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, 210093, Nanjing, China
| | - Lin He
- The Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, 100875, Beijing, China.
| | - Zengfeng Di
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China.
| | - Xi Wang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
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28
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Bouakline F, Fischer EW, Saalfrank P. A quantum-mechanical tier model for phonon-driven vibrational relaxation dynamics of adsorbates at surfaces. J Chem Phys 2019; 150:244105. [DOI: 10.1063/1.5099902] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- F. Bouakline
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
| | - E. W. Fischer
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
| | - P. Saalfrank
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
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29
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Wyrick J, Wang X, Namboodiri P, Schmucker SW, Kashid RV, Silver RM. Atom-by-Atom Construction of a Cyclic Artificial Molecule in Silicon. Nano Lett 2018; 18:7502-7508. [PMID: 30428677 PMCID: PMC6505699 DOI: 10.1021/acs.nanolett.8b02919] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Hydrogen atoms on a silicon surface, H-Si (100), behave as a resist that can be patterned with perfect atomic precision using a scanning tunneling microscope. When a hydrogen atom is removed in this manner, the underlying silicon presents a chemically active site, commonly referred to as a dangling bond. It has been predicted that individual dangling bonds function as artificial atoms, which, if grouped together, can form designer molecules on the H-Si (100) surface. Here, we present an artificial ring structure molecule spanning three dimer rows, constructed from dangling bonds, and verified by spectroscopic measurement of its molecular orbitals. We found that removing 8 hydrogen atoms resulted in a molecular analog to 1,4-disilylene-hexasilabenzene (Si8H8). Scanning tunneling spectroscopic measurements reveal molecular π and π* orbitals that agree with those expected for the same molecule in a vacuum; this is validated by density functional theory calculations of the dangling bond system on a silicon slab that show direct links both to the experimental results and to calculations for the isolated molecule. We believe the unique electronic structure of artificial molecules constructed in this manner can be engineered to enable future molecule-based electronics, surface catalytic functionality, and templating for subsequent site-selective deposition.
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Affiliation(s)
- Jonathan Wyrick
- Nanoscale Device Characterization Division, National Institute for Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Xiqiao Wang
- Nanoscale Device Characterization Division, National Institute for Standards and Technology, Gaithersburg, Maryland 20899, United States
- Chemical Physics Program, University of Maryland, College Park, Maryland 20742, United States
| | - Pradeep Namboodiri
- Nanoscale Device Characterization Division, National Institute for Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Scott W. Schmucker
- Nanoscale Device Characterization Division, National Institute for Standards and Technology, Gaithersburg, Maryland 20899, United States
- Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Ranjit V. Kashid
- Nanoscale Device Characterization Division, National Institute for Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Richard M. Silver
- Nanoscale Device Characterization Division, National Institute for Standards and Technology, Gaithersburg, Maryland 20899, United States
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30
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Škereň T, Pascher N, Garnier A, Reynaud P, Rolland E, Thuaire A, Widmer D, Jehl X, Fuhrer A. CMOS platform for atomic-scale device fabrication. Nanotechnology 2018; 29:435302. [PMID: 30070975 DOI: 10.1088/1361-6528/aad7ab] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Controlled atomic scale fabrication based on scanning probe patterning or surface assembly typically involves a complex process flow, stringent requirements for an ultra-high vacuum environment, long fabrication times and, consequently, limited throughput and device yield. We demonstrate a device platform that overcomes these limitations by integrating scanning-probe based dopant device fabrication with a CMOS-compatible process flow. Silicon on insulator substrates are used featuring a reconstructed Si(001):H surface that is protected by a capping chip and has pre-implanted contacts ready for scanning tunneling microscope (STM) patterning. Processing in ultra-high vacuum is thereby reduced to a few critical steps. Subsequent reintegration of the samples into the CMOS process flow opens the door to successful application of STM fabricated dopant devices in more complex device architectures. Full functionality of this approach is demonstrated with magnetotransport measurements on degenerately doped STM patterned Si:P nanowires up to room temperature.
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Affiliation(s)
- Tomáš Škereň
- IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
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31
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Achal R, Rashidi M, Croshaw J, Churchill D, Taucer M, Huff T, Cloutier M, Pitters J, Wolkow RA. Lithography for robust and editable atomic-scale silicon devices and memories. Nat Commun 2018; 9:2778. [PMID: 30038236 PMCID: PMC6056515 DOI: 10.1038/s41467-018-05171-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 06/15/2018] [Indexed: 12/02/2022] Open
Abstract
At the atomic scale, there has always been a trade-off between the ease of fabrication of structures and their thermal stability. Complex structures that are created effortlessly often disorder above cryogenic conditions. Conversely, systems with high thermal stability do not generally permit the same degree of complex manipulations. Here, we report scanning tunneling microscope (STM) techniques to substantially improve automated hydrogen lithography (HL) on silicon, and to transform state-of-the-art hydrogen repassivation into an efficient, accessible error correction/editing tool relative to existing chemical and mechanical methods. These techniques are readily adapted to many STMs, together enabling fabrication of error-free, room-temperature stable structures of unprecedented size. We created two rewriteable atomic memories (1.1 petabits per in2), storing the alphabet letter-by-letter in 8 bits and a piece of music in 192 bits. With HL no longer faced with this trade-off, practical silicon-based atomic-scale devices are poised to make rapid advances towards their full potential. Manipulation at the atomic scale comes with a trade-off between simplicity and thermal stability. Here, Achal et al. demonstrate improved automated hydrogen lithography and repassivation, enabling error-corrected atomic writing of large-scale structures/memories that are stable at room temperature.
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Affiliation(s)
- Roshan Achal
- Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada. .,Quantum Silicon, Inc., Edmonton, AB, T6G 2M9, Canada.
| | - Mohammad Rashidi
- Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Quantum Silicon, Inc., Edmonton, AB, T6G 2M9, Canada
| | - Jeremiah Croshaw
- Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - David Churchill
- Memorial University of Newfoundland, St. John's, NL, A1B 3X5, Canada
| | - Marco Taucer
- Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Quantum Silicon, Inc., Edmonton, AB, T6G 2M9, Canada
| | - Taleana Huff
- Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Quantum Silicon, Inc., Edmonton, AB, T6G 2M9, Canada
| | - Martin Cloutier
- Nanotechnology Research Centre, National Research Council of Canada, Edmonton, AB, T6G 2M9, Canada
| | - Jason Pitters
- Quantum Silicon, Inc., Edmonton, AB, T6G 2M9, Canada.,Nanotechnology Research Centre, National Research Council of Canada, Edmonton, AB, T6G 2M9, Canada
| | - Robert A Wolkow
- Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Quantum Silicon, Inc., Edmonton, AB, T6G 2M9, Canada.,Nanotechnology Research Centre, National Research Council of Canada, Edmonton, AB, T6G 2M9, Canada
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32
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Smith R, Bowler DR. Reaction paths of alane dissociation on the Si(0 0 1) surface. J Phys Condens Matter 2018; 30:105002. [PMID: 29369048 DOI: 10.1088/1361-648x/aaaa91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Building on our earlier study, we examine the kinetic barriers to decomposition of alane, AlH3, on the Si(0 0 1) surface, using the nudged elastic band approach within density functional theory. We find that the initial decomposition to AlH with two H atoms on the surface proceeds without a significant barrier. There are several pathways available to lose the final hydrogen, though these present barriers of up to 1 eV. Incorporation is more challenging, with the initial structures less stable in several cases than the starting structures, just as was found for phosphorus. We identify a stable route for Al incorporation following selective surface hydrogen desorption (e.g. by scanning tunneling microscope tip). The overall process parallels PH3, and indicates that atomically precise acceptor doping should be possible.
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Affiliation(s)
- Richard Smith
- London Centre for Nanotechnology, UCL, 17-19 Gordon St, London WC1H 0AH, United Kingdom. Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT, United Kingdom. Thomas Young Centre, UCL, Gower St, London WC1E 6BT, United Kingdom
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33
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Wang X, Hagmann JA, Namboodiri P, Wyrick J, Li K, Murray RE, Myers A, Misenkosen F, Stewart MD, Richter CA, Silver RM. Quantifying atom-scale dopant movement and electrical activation in Si:P monolayers. Nanoscale 2018; 10:4488-4499. [PMID: 29459919 DOI: 10.1039/c7nr07777g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Advanced hydrogen lithography techniques and low-temperature epitaxial overgrowth enable the patterning of highly phosphorus-doped silicon (Si:P) monolayers (ML) with atomic precision. This approach to device fabrication has made Si:P monolayer systems a testbed for multiqubit quantum computing architectures and atomically precise 2-D superlattice designs whose behaviors are directly tied to the deterministic placement of single dopants. However, dopant segregation, diffusion, surface roughening, and defect formation during the encapsulation overgrowth introduce large uncertainties to the exact dopant placement and activation ratio. In this study, we develop a unique method by combining dopant segregation/diffusion models with sputter profiling simulation to monitor and control, at the atomic scale, dopant movement using room-temperature grown locking layers (LLs). We explore the impact of LL growth rate, thickness, rapid thermal annealing, surface accumulation, and growth front roughness on dopant confinement, local crystalline quality, and electrical activation within Si:P 2-D systems. We demonstrate that dopant movement can be more efficiently suppressed by increasing the LL growth rate than by increasing the LL thickness. We find that the dopant segregation length can be suppressed below a single Si lattice constant by increasing the LL growth rates at room temperature while maintaining epitaxy. Although dopant diffusivity within the LL is found to remain high (on the order of 10-17 cm2 s-1) even below the hydrogen desorption temperature, we demonstrate that exceptionally sharp dopant confinement with high electrical quality within Si:P monolayers can be achieved by combining a high LL growth rate with low-temperature LL rapid thermal annealing. The method developed in this study provides a key tool for 2-D fabrication techniques that require precise dopant placement to suppress, quantify, and predict a single dopant's movement at the atomic scale.
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Affiliation(s)
- Xiqiao Wang
- National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, Maryland 20899, USA.
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34
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Zhang J, Ji WX, Zhang CW, Li P, Wang PJ. Nontrivial topology and topological phase transition in two-dimensional monolayer Tl. Phys Chem Chem Phys 2018; 20:24790-24795. [DOI: 10.1039/c8cp02649a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Topological insulating material with dissipationless edge states is a rising star in spintronics.
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Affiliation(s)
- Jin Zhang
- School of Physics and Technology
- University of Jinan
- Jinan
- People's Republic of China
| | - Wei-xiao Ji
- School of Physics and Technology
- University of Jinan
- Jinan
- People's Republic of China
| | - Chang-wen Zhang
- School of Physics and Technology
- University of Jinan
- Jinan
- People's Republic of China
| | - Ping Li
- School of Physics and Technology
- University of Jinan
- Jinan
- People's Republic of China
| | - Pei-ji Wang
- School of Physics and Technology
- University of Jinan
- Jinan
- People's Republic of China
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35
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Bouakline F, Lorenz U, Melani G, Paramonov GK, Saalfrank P. Isotopic effects in vibrational relaxation dynamics of H on a Si(100) surface. J Chem Phys 2017; 147:144703. [PMID: 29031276 DOI: 10.1063/1.4994635] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In a recent paper [U. Lorenz and P. Saalfrank, Chem. Phys. 482, 69 (2017)], we proposed a robust scheme to set up a system-bath model Hamiltonian, describing the coupling of adsorbate vibrations (system) to surface phonons (bath), from first principles. The method is based on an embedded cluster approach, using orthogonal coordinates for system and bath modes, and an anharmonic phononic expansion of the system-bath interaction up to second order. In this contribution, we use this model Hamiltonian to calculate vibrational relaxation rates of H-Si and D-Si bending modes, coupled to a fully H(D)-covered Si(100)-(2×1) surface, at zero temperature. The D-Si bending mode has an anharmonic frequency lying inside the bath frequency spectrum, whereas the H-Si bending mode frequency is outside the bath Debye band. Therefore, in the present calculations, we only take into account one-phonon system-bath couplings for the D-Si system and both one- and two-phonon interaction terms in the case of H-Si. The computation of vibrational lifetimes is performed with two different approaches, namely, Fermi's golden rule, and a generalized Bixon-Jortner model built in a restricted vibrational space of the adsorbate-surface zeroth-order Hamiltonian. For D-Si, the Bixon-Jortner Hamiltonian can be solved by exact diagonalization, serving as a benchmark, whereas for H-Si, an iterative scheme based on the recursive residue generation method is applied, with excellent convergence properties. We found that the lifetimes obtained with perturbation theory, albeit having almost the same order of magnitude-a few hundred fs for D-Si and a couple of ps for H-Si-, are strongly dependent on the discretized numerical representation of the bath spectral density. On the other hand, the Bixon-Jortner model is free of such numerical deficiencies, therefore providing better estimates of vibrational relaxation rates, at a very low computational cost. The results obtained with this model clearly show a net exponential decay of the time-dependent survival probability for the H-Si initial vibrational state, allowing an easy extraction of the bending mode "lifetime." This is in contrast with the D-Si system, whose survival probability exhibits a non-monotonic decay, making it difficult to define such a lifetime. This different behavior of the vibrational decay is rationalized in terms of the power spectrum of the adsorbate-surface system. In the case of D-Si, it consists of several, non-uniformly distributed peaks around the bending mode frequency, whereas the H-Si spectrum exhibits a single Lorentzian lineshape, whose width corresponds to the calculated lifetime. The present work gives some insight into mechanisms of vibration-phonon coupling at surfaces. It also serves as a benchmark for multidimensional system-bath quantum dynamics, for comparison with approximate schemes such as reduced, open-system density matrix theory (where the bath is traced out and a Liouville-von Neumann equation is solved) or approximate wavefunction methods to solve the combined system-bath Schrödinger equation.
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Affiliation(s)
- F Bouakline
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
| | - U Lorenz
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
| | - G Melani
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
| | - G K Paramonov
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
| | - P Saalfrank
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm, Germany
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36
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Smith RL, Bowler DR. Alane adsorption and dissociation on the Si(0 0 1) surface. J Phys Condens Matter 2017; 29:395001. [PMID: 28685709 DOI: 10.1088/1361-648x/aa7e48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We used DFT to study the energetics of the decomposition of alane, AlH3, on the Si(0 0 1) surface, as the acceptor complement to PH3. Alane forms a dative bond with the raised atoms of silicon surface dimers, via the Si atom lone pair. We calculated the energies of various structures along the pathway of successive dehydrogenation events following adsorption: AlH2, AlH and Al, finding a gradual, significant decrease in energy. For each stage, we analyse the structure and bonding, and present simulated STM images of the lowest energy structures. Finally, we find that the energy of Al atoms incorporated into the surface, ejecting a Si atom, is comparable to Al adatoms. These findings show that Al incorporation is likely to be as precisely controlled as P incorporation, if slightly less easy to achieve.
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Affiliation(s)
- R L Smith
- London Centre for Nanotechnology, 17-19 Gordon St, London, WC1H 0AH, United Kingdom. Department of Physics & Astronomy, UCL Gower St, London, WC1E 6BT, United Kingdom. Thomas Young Centre, UCL Gower St, London, WC1E 6BT, United Kingdom
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37
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Huff TR, Labidi H, Rashidi M, Koleini M, Achal R, Salomons MH, Wolkow RA. Atomic White-Out: Enabling Atomic Circuitry through Mechanically Induced Bonding of Single Hydrogen Atoms to a Silicon Surface. ACS Nano 2017; 11:8636-8642. [PMID: 28719182 DOI: 10.1021/acsnano.7b04238] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report the mechanically induced formation of a silicon-hydrogen covalent bond and its application in engineering nanoelectronic devices. We show that using the tip of a noncontact atomic force microscope (NC-AFM), a single hydrogen atom could be vertically manipulated. When applying a localized electronic excitation, a single hydrogen atom is desorbed from the hydrogen-passivated surface and can be transferred to the tip apex, as evidenced from a unique signature in frequency shift curves. In the absence of tunnel electrons and electric field in the scanning probe microscope junction at 0 V, the hydrogen atom at the tip apex is brought very close to a silicon dangling bond, inducing the mechanical formation of a silicon-hydrogen covalent bond and the passivation of the dangling bond. The functionalized tip was used to characterize silicon dangling bonds on the hydrogen-silicon surface, which was shown to enhance the scanning tunneling microscope contrast, and allowed NC-AFM imaging with atomic and chemical bond contrasts. Through examples, we show the importance of this atomic-scale mechanical manipulation technique in the engineering of the emerging technology of on-surface dangling bond based nanoelectronic devices.
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Affiliation(s)
- Taleana R Huff
- Department of Physics, University of Alberta , Edmonton, Alberta T6G 2E1, Canada
- Quantum Silicon, Inc. , Edmonton, Alberta T6G 2M9, Canada
| | - Hatem Labidi
- Department of Physics, University of Alberta , Edmonton, Alberta T6G 2E1, Canada
- National Institute for Nanotechnology, National Research Council of Canada , Edmonton, Alberta T6G 2M9, Canada
| | - Mohammad Rashidi
- Department of Physics, University of Alberta , Edmonton, Alberta T6G 2E1, Canada
- National Institute for Nanotechnology, National Research Council of Canada , Edmonton, Alberta T6G 2M9, Canada
| | - Mohammad Koleini
- Department of Physics, University of Alberta , Edmonton, Alberta T6G 2E1, Canada
- National Institute for Nanotechnology, National Research Council of Canada , Edmonton, Alberta T6G 2M9, Canada
| | - Roshan Achal
- Department of Physics, University of Alberta , Edmonton, Alberta T6G 2E1, Canada
- Quantum Silicon, Inc. , Edmonton, Alberta T6G 2M9, Canada
| | - Mark H Salomons
- Quantum Silicon, Inc. , Edmonton, Alberta T6G 2M9, Canada
- National Institute for Nanotechnology, National Research Council of Canada , Edmonton, Alberta T6G 2M9, Canada
| | - Robert A Wolkow
- Department of Physics, University of Alberta , Edmonton, Alberta T6G 2E1, Canada
- Quantum Silicon, Inc. , Edmonton, Alberta T6G 2M9, Canada
- National Institute for Nanotechnology, National Research Council of Canada , Edmonton, Alberta T6G 2M9, Canada
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38
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Kim SM, Lee C, Goddeti KC, Park JY. Hot plasmonic electron-driven catalytic reactions on patterned metal-insulator-metal nanostructures. Nanoscale 2017; 9:11667-11677. [PMID: 28776052 DOI: 10.1039/c7nr02805a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The smart design of plasmonic nanostructures offers a unique capability for the efficient conversion of solar energy into chemical energy by strong interactions with resonant photons through the excitation of surface plasmon resonance, which increases the prospect of using sunlight in environmental and energy applications. Here, we show that the catalytic activity of CO oxidation can be tuned by using new model systems: two-dimensional (2D) arrays of metal-insulator-metal (MIM) plasmonic nanoislands designed to efficiently shuttle hot plasmonic electrons. Hot plasmonic electrons are generated upon the absorption of photons on noble metals, followed by the injection of these hot electrons into the Pt nanoparticles through tunneling or Schottky emission mechanisms, depending on the energy of the hot electrons. We found that these MIM nanostructures exhibit higher catalytic activity (i.e. by 40-110%) under light irradiation, revealing a significant impact on the catalytic activity for CO oxidation. The thickness dependence of the enhancement of catalytic activity on the oxide layers is consistent with the tunneling mechanism of hot electron flows. The results imply that surface plasmon-induced hot electron flows by light absorption significantly influence the catalytic activity of CO oxidation.
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Affiliation(s)
- Sun Mi Kim
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science, Daejeon 305-701, Republic of Korea.
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40
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Borca B, Michnowicz T, Pétuya R, Pristl M, Schendel V, Pentegov I, Kraft U, Klauk H, Wahl P, Gutzler R, Arnau A, Schlickum U, Kern K. Electric-Field-Driven Direct Desulfurization. ACS Nano 2017; 11:4703-4709. [PMID: 28437066 DOI: 10.1021/acsnano.7b00612] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The ability to elucidate the elementary steps of a chemical reaction at the atomic scale is important for the detailed understanding of the processes involved, which is key to uncover avenues for improved reaction paths. Here, we track the chemical pathway of an irreversible direct desulfurization reaction of tetracenothiophene adsorbed on the Cu(111) closed-packed surface at the submolecular level. Using the precise control of the tip position in a scanning tunneling microscope and the electric field applied across the tunnel junction, the two carbon-sulfur bonds of a thiophene unit are successively cleaved. Comparison of spatially mapped molecular states close to the Fermi level of the metallic substrate acquired at each reaction step with density functional theory calculations reveals the two elementary steps of this reaction mechanism. The first reaction step is activated by an electric field larger than 2 V nm-1, practically in absence of tunneling electrons, opening the thiophene ring and leading to a transient intermediate. Subsequently, at the same threshold electric field and with simultaneous injection of electrons into the molecule, the exergonic detachment of the sulfur atom is triggered. Thus, a stable molecule with a bifurcated end is obtained, which is covalently bound to the metallic surface. The sulfur atom is expelled from the vicinity of the molecule.
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Affiliation(s)
- Bogdana Borca
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
- National Institute of Materials Physics , 077125 Măgurele-Ilfov, Romania
| | - Tomasz Michnowicz
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
| | - Rémi Pétuya
- Donostia International Physics Centre , E-20018 Donostia - San Sebastián, Spain
| | - Marcel Pristl
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
| | - Verena Schendel
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
| | - Ivan Pentegov
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
| | - Ulrike Kraft
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
| | - Hagen Klauk
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
| | - Peter Wahl
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
- SUPA, School of Physics and Astronomy, University of St. Andrews , North Haugh, St. Andrews KY16 9SS, United Kingdom
| | - Rico Gutzler
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
| | - Andrés Arnau
- Donostia International Physics Centre , E-20018 Donostia - San Sebastián, Spain
- Departamento de Física de Materiales UPV/EHU and Material Physics Center (MPC), Centro Mixto CSIC-UPV/EHU , E-20018 Donostia - San Sebastián, Spain
| | - Uta Schlickum
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
| | - Klaus Kern
- Max Planck Institute for Solid State Research , 70569 Stuttgart, Germany
- Institut de Physique , École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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41
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Abstract
Tip-based nanofabrication (TBN) is a family of emerging nanofabrication techniques that use a nanometer scale tip to fabricate nanostructures. In this review, we first introduce the history of the TBN and the technology development. We then briefly review various TBN techniques that use different physical or chemical mechanisms to fabricate features and discuss some of the state-of-the-art techniques. Subsequently, we focus on those TBN methods that have demonstrated potential to scale up the manufacturing throughput. Finally, we discuss several research directions that are essential for making TBN a scalable nano-manufacturing technology.
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Møller M, Jarvis SP, Guérinet L, Sharp P, Woolley R, Rahe P, Moriarty P. Automated extraction of single H atoms with STM: tip state dependency. Nanotechnology 2017; 28:075302. [PMID: 28074783 DOI: 10.1088/1361-6528/28/7/075302] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The atomistic structure of the tip apex plays a crucial role in performing reliable atomic-scale surface and adsorbate manipulation using scanning probe techniques. We have developed an automated extraction routine for controlled removal of single hydrogen atoms from the H:Si(100) surface. The set of atomic extraction protocols detect a variety of desorption events during scanning tunneling microscope (STM)-induced modification of the hydrogen-passivated surface. The influence of the tip state on the probability for hydrogen removal was examined by comparing the desorption efficiency for various classifications of STM topographs (rows, dimers, atoms, etc). We find that dimer-row-resolving tip apices extract hydrogen atoms most readily and reliably (and with least spurious desorption), while tip states which provide atomic resolution counter-intuitively have a lower probability for single H atom removal.
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Affiliation(s)
- Morten Møller
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
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Kislitsyn DA, Mills JM, Kocevski V, Chiu SK, DeBenedetti WJI, Gervasi CF, Taber BN, Rosenfield AE, Eriksson O, Rusz J, Goforth AM, Nazin GV. Communication: Visualization and spectroscopy of defects induced by dehydrogenation in individual silicon nanocrystals. J Chem Phys 2016; 144:241102. [DOI: 10.1063/1.4954833] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Dmitry A. Kislitsyn
- Department of Chemistry and Biochemistry, Materials Science Institute, Oregon Center for Optical, Molecular and Quantum Science, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
| | - Jon M. Mills
- Department of Chemistry and Biochemistry, Materials Science Institute, Oregon Center for Optical, Molecular and Quantum Science, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
| | - Vancho Kocevski
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - Sheng-Kuei Chiu
- Department of Chemistry, Portland State University, Portland, Oregon 97201, USA
| | | | - Christian F. Gervasi
- Department of Chemistry and Biochemistry, Materials Science Institute, Oregon Center for Optical, Molecular and Quantum Science, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
| | - Benjamen N. Taber
- Department of Chemistry and Biochemistry, Materials Science Institute, Oregon Center for Optical, Molecular and Quantum Science, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
| | - Ariel E. Rosenfield
- Department of Chemistry and Biochemistry, Materials Science Institute, Oregon Center for Optical, Molecular and Quantum Science, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
| | - Olle Eriksson
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - Ján Rusz
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - Andrea M. Goforth
- Department of Chemistry, Portland State University, Portland, Oregon 97201, USA
| | - George V. Nazin
- Department of Chemistry and Biochemistry, Materials Science Institute, Oregon Center for Optical, Molecular and Quantum Science, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, USA
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González-Herrero H, Pou P, Lobo-Checa J, Fernández-Torre D, Craes F, Martínez-Galera AJ, Ugeda MM, Corso M, Ortega JE, Gómez-Rodríguez JM, Pérez R, Brihuega I. Graphene Tunable Transparency to Tunneling Electrons: A Direct Tool To Measure the Local Coupling. ACS Nano 2016; 10:5131-5144. [PMID: 27110642 DOI: 10.1021/acsnano.6b00322] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The local interaction between graphene and a host substrate strongly determines the actual properties of the graphene layer. Here we show that scanning tunneling microscopy (STM) can selectively help to visualize either the graphene layer or the substrate underneath, or even both at the same time, providing a comprehensive picture of this coupling with atomic precision and high energy resolution. We demonstrate this for graphene on Cu(111). Our spectroscopic data show that, in the vicinity of the Fermi level, graphene π bands are well preserved presenting a small n-doping induced by Cu(111) surface state electrons. Such results are corroborated by Angle-Resolved Photoemission Spectra (ARPES) and Density Functional Theory with van der Waals (DFT + vdW) calculations. Graphene tunable transparency also allows the investigation of the interaction between the substrate and foreign species (such as atomic H or C vacancies) on the graphene layer. Our calculations explain graphene tunable transparency in terms of the rather different decay lengths of the graphene Dirac π states and the metal surface state, suggesting that it should apply to a good number of graphene/substrate systems.
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Affiliation(s)
- Héctor González-Herrero
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid , E-28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , E-28049 Madrid, Spain
| | - Pablo Pou
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , E-28049 Madrid, Spain
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid , E-28049 Madrid, Spain
| | - Jorge Lobo-Checa
- Centro de Física de Materiales (CSIC-UPV-EHU) and Materials Physics Center (MPC) , Manuel Lardizábal 5, E-20018 San Sebastián, Spain
| | - Delia Fernández-Torre
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid , E-28049 Madrid, Spain
| | - Fabian Craes
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | - Antonio J Martínez-Galera
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid , E-28049 Madrid, Spain
- II. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | - Miguel M Ugeda
- CIC nanoGUNE , 20018 Donostia-San Sebastian, Spain
- Ikerbasque, Basque Foundation for Science , 48013 Bilbao, Spain
| | - Martina Corso
- Centro de Física de Materiales (CSIC-UPV-EHU) and Materials Physics Center (MPC) , Manuel Lardizábal 5, E-20018 San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science , 48013 Bilbao, Spain
| | - J Enrique Ortega
- Centro de Física de Materiales (CSIC-UPV-EHU) and Materials Physics Center (MPC) , Manuel Lardizábal 5, E-20018 San Sebastián, Spain
- Donostia International Physics Center DIPC , E-20018 San Sebastián, Spain
- Departamento de Física Aplicada I, Universidad del País Vasco , E-20018 San Sebastián, Spain
| | - José M Gómez-Rodríguez
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid , E-28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , E-28049 Madrid, Spain
| | - Rubén Pérez
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , E-28049 Madrid, Spain
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid , E-28049 Madrid, Spain
| | - Iván Brihuega
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid , E-28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , E-28049 Madrid, Spain
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45
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Gonzalez-Herrero H, Gomez-Rodriguez JM, Mallet P, Moaied M, Palacios JJ, Salgado C, Ugeda MM, Veuillen JY, Yndurain F, Brihuega I. Atomic-scale control of graphene magnetism by using hydrogen atoms. Science 2016; 352:437-41. [DOI: 10.1126/science.aad8038] [Citation(s) in RCA: 453] [Impact Index Per Article: 56.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/21/2016] [Indexed: 01/29/2023]
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Abstract
We demonstrate for the first time to our knowledge that controllable dissociation of PH3 adsorption products PHx (x = 2, 1) can be realized by STM (scanning tunneling microscope) manipulation techniques at room temperature. Five dissociative products and their geometric structures are identified via combining STM experiments and first-principle calculations and simulations. In total we realize nine kinds of controllable dissociations by applying a voltage pulse among the PH3-related structures on Si(001). The dissociation rates of the five most common reactions are measured by the I-t spectrum method as a function of voltage. The suddenly increased dissociation rate at 3.3 V indicates a transition from multivibrational excitation to single-step excitation induced by inelastic tunneling electrons. Our studies prove that selectively breaking the chemical bonds of a single molecule on semiconductor surface by STM manipulation technique is feasible.
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Affiliation(s)
- Qin Liu
- Department of Physics, The Chinese University of Hong Kong, Shatin, New Territory, Hong Kong, People's Republic of China. Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621908, People's Republic of China
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47
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Néel N, Lattelais M, Bocquet ML, Kröger J. Depopulation of Single-Phthalocyanine Molecular Orbitals upon Pyrrolic-Hydrogen Abstraction on Graphene. ACS Nano 2016; 10:2010-6. [PMID: 26812093 DOI: 10.1021/acsnano.5b06153] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Single-molecule chemistry with a scanning tunneling microscope has preponderantly been performed on metal surfaces. The molecule-metal hybridization, however, is often detrimental to genuine molecular properties and obscures their changes upon chemical reactions. We used graphene on Ir(111) to reduce the coupling between Ir(111) and adsorbed phthalocyanine molecules. By local electron injection from the tip of a scanning tunneling microscope the two pyrrolic H atoms were removed from single phthalocyanines. The detachment of the H atom pair induced a strong modification of the molecular electronic structure, albeit with no change in the adsorption geometry. Spectra and maps of the differential conductance combined with density functional calculations unveiled the entire depopulation of the highest occupied molecular orbital upon H abstraction. Occupied π states of intact molecules are proposed to be emptied via intramolecular electron transfer to dangling σ states of H-free N atoms.
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Affiliation(s)
- Nicolas Néel
- Institut für Physik, Technische Universität Ilmenau , D-98693 Ilmenau, Germany
| | - Marie Lattelais
- Department of Chemistry, UMR ENS-CNRS-UPMC 8640, Ecole Normale Supérieure , F-75005 Paris, France
| | - Marie-Laure Bocquet
- Department of Chemistry, UMR ENS-CNRS-UPMC 8640, Ecole Normale Supérieure , F-75005 Paris, France
| | - Jörg Kröger
- Institut für Physik, Technische Universität Ilmenau , D-98693 Ilmenau, Germany
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48
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Gao L, Pal PP, Seideman T, Guisinger NP, Guest JR. Current-Driven Hydrogen Desorption from Graphene: Experiment and Theory. J Phys Chem Lett 2016; 7:486-494. [PMID: 26787160 DOI: 10.1021/acs.jpclett.5b02471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Electron-stimulated desorption of hydrogen from the graphene/SiC(0001) surface at room temperature was investigated with ultrahigh vacuum scanning tunneling microscopy and ab initio calculations in order to elucidate the desorption mechanisms and pathways. Two different desorption processes were observed. In the high electron energy regime (4-8 eV), the desorption yield is independent of both voltage and current, which is attributed to the direct electronic excitation of the C-H bond. In the low electron energy regime (2-4 eV), however, the desorption yield exhibits a threshold dependence on voltage, which is explained by the vibrational excitation of the C-H bond via transient ionization induced by inelastic tunneling electrons. The observed current independence of the desorption yield suggests that the vibrational excitation is a single-electron process. We also observed that the curvature of graphene dramatically affects hydrogen desorption. Desorption from concave regions was measured to be much more probable than desorption from convex regions in the low electron energy regime (∼2 eV), as would be expected from the identified desorption mechanism.
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Affiliation(s)
- Li Gao
- Department of Physics and Astronomy, California State University , Northridge, California 91330, United States
- Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Partha Pratim Pal
- Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States
| | - Tamar Seideman
- Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States
| | - Nathan P Guisinger
- Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Jeffrey R Guest
- Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States
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49
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Warschkow O, Curson NJ, Schofield SR, Marks NA, Wilson HF, Radny MW, Smith PV, Reusch TCG, McKenzie DR, Simmons MY. Reaction paths of phosphine dissociation on silicon (001). J Chem Phys 2016; 144:014705. [DOI: 10.1063/1.4939124] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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50
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Sprenger JK, Cavanagh AS, Sun H, Wahl KJ, Roshko A, George SM. Electron Enhanced Growth of Crystalline Gallium Nitride Thin Films at Room Temperature and 100 °C Using Sequential Surface Reactions. Chem Mater 2016; 28:10.1021/acs.chemmater.6b00676. [PMID: 31092972 PMCID: PMC6513341 DOI: 10.1021/acs.chemmater.6b00676] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Low energy electrons may provide mechanisms to enhance thin film growth at low temperatures. As a proof of concept, this work demonstrated the deposition of gallium nitride (GaN) films over areas of ∼5 cm2 at room temperature and 100 °C using electrons with a low energy of 50 eV from an electron flood gun. The GaN films were deposited on Si(111) wafers using a cycle of reactions similar to the sequence employed for GaN atomic layer deposition (ALD). Trimethylgallium (Ga(CH3)3, TMG), hydrogen (H) radicals and ammonia (NH3) were employed as the reactants with electron exposures included in the reaction cycle after the TMG/H and NH3 exposures. A number of ex situ techniques were then employed to analyze the GaN films. Spectroscopic ellipsometry measurements revealed that the GaN films grew linearly with the number of reaction cycles. Linear growth rates of up to 1.3 Å/ cycle were obtained from the surface areas receiving the highest electron fluxes. Grazing incidence X-ray diffraction analysis revealed polycrystalline GaN films with the wurtzite crystal structure. Transmission electron microscopy (TEM) images showed crystalline grains with diameters between 2 and 10 nm depending on the growth temperature. X-ray photoelectron spectroscopy depth-profiling displayed no oxygen contamination when the GaN films were capped with Al prior to atmospheric exposure. However, the carbon concentrations in the GaN films were 10-35 at. %. The mechanism for the low temperature GaN growth is believed to result from the electron stimulated desorption (ESD) of hydrogen. Hydrogen ESD yields dangling bonds that facilitate Ga-N bond formation. Mass spectrometry measurements performed concurrently with the reaction cycles revealed increases in the pressure of H2 and various GaN etch products during the electron beam exposures. The amount of H2 and GaN etch products increased with electron beam energy from 25 to 200 eV. These results indicate that the GaN growth occurs with competing GaN etching during the reaction cycles.
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Affiliation(s)
- Jaclyn K Sprenger
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Andrew S Cavanagh
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Huaxing Sun
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Kathryn J Wahl
- Chemistry Division, Naval Research Laboratory, Washington, DC 20375, United States
| | - Alexana Roshko
- National Institute of Standards and Technology, Boulder, Colorado 80305, United States
| | - Steven M George
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, United States
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