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Chen N, Li S, Zhao P, Liu R, Xie Y, Lin JL, Nijhuis CA, Xu B, Zhang L, Xu H, Li Y. Extreme long-lifetime self-assembled monolayer for air-stable molecular junctions. SCIENCE ADVANCES 2023; 9:eadh3412. [PMID: 37851815 PMCID: PMC10584343 DOI: 10.1126/sciadv.adh3412] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 09/14/2023] [Indexed: 10/20/2023]
Abstract
The molecular electronic devices based on self-assembled monolayer (SAM) on metal surfaces demonstrate novel electronic functions for device minimization yet are unable to realize in practical applications, due to their instability against oxidation of the sulfur-metal bond. This paper describes an alternative to the thiolate anchoring group to form stable SAMs on gold by selenides anchoring group. Because of the formation of strong selenium-gold bonds, these stable SAMs allow us to incorporate them in molecular tunnel junctions to yield extremely stable junctions for over 200 days. A detailed structural characterization supported by spectroscopy and first-principles modeling shows that the oxidation process is much slower with the selenium-gold bond than the sulfur-gold bond, and the selenium-gold bond is strong enough to avoid bond breaking even when it is eventually oxidized. This proof of concept demonstrates that the extraordinarily stable SAMs derived from selenides are useful for long-lived molecular electronic devices and can possibly become important in many air-stable applications involving SAMs.
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Affiliation(s)
- Ningyue Chen
- Key Laboratory of Organic Optoelectronics and Molecular Engineering and Laboratory of Flexible Electronics Technology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Shuwei Li
- Center for Combustion Energy, Tsinghua University, Beijing 100084, China
- School of Vehicle and Mobility, and State Key Laboratory of Intelligent Green Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Peng Zhao
- Key Laboratory of Organic Optoelectronics and Molecular Engineering and Laboratory of Flexible Electronics Technology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Ran Liu
- School of Electrical and Computer Engineering, University of Georgia, Athens, GA 30602, USA
| | - Yu Xie
- Key Laboratory of Organic Optoelectronics and Molecular Engineering and Laboratory of Flexible Electronics Technology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jin-Liang Lin
- Key Laboratory of Organic Optoelectronics and Molecular Engineering and Laboratory of Flexible Electronics Technology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Christian A. Nijhuis
- Hybrid Materials for Opto-Electronics Group, Department of Molecules and Materials, MESA+ Institute for Nanotechnology, Molecules Centre and Centre for Brain-Inspired Nano Systems, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, Netherlands
| | - Bingqian Xu
- School of Electrical and Computer Engineering, University of Georgia, Athens, GA 30602, USA
| | - Liang Zhang
- Center for Combustion Energy, Tsinghua University, Beijing 100084, China
- School of Vehicle and Mobility, and State Key Laboratory of Intelligent Green Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Huaping Xu
- Key Laboratory of Organic Optoelectronics and Molecular Engineering and Laboratory of Flexible Electronics Technology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yuan Li
- Key Laboratory of Organic Optoelectronics and Molecular Engineering and Laboratory of Flexible Electronics Technology, Department of Chemistry, Tsinghua University, Beijing 100084, China
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2
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Li T, Bandari VK, Schmidt OG. Molecular Electronics: Creating and Bridging Molecular Junctions and Promoting Its Commercialization. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209088. [PMID: 36512432 DOI: 10.1002/adma.202209088] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/28/2022] [Indexed: 06/02/2023]
Abstract
Molecular electronics is driven by the dream of expanding Moore's law to the molecular level for next-generation electronics through incorporating individual or ensemble molecules into electronic circuits. For nearly 50 years, numerous efforts have been made to explore the intrinsic properties of molecules and develop diverse fascinating molecular electronic devices with the desired functionalities. The flourishing of molecular electronics is inseparable from the development of various elegant methodologies for creating nanogap electrodes and bridging the nanogap with molecules. This review first focuses on the techniques for making lateral and vertical nanogap electrodes by breaking, narrowing, and fixed modes, and highlights their capabilities, applications, merits, and shortcomings. After summarizing the approaches of growing single molecules or molecular layers on the electrodes, the methods of constructing a complete molecular circuit are comprehensively grouped into three categories: 1) directly bridging one-molecule-electrode component with another electrode, 2) physically bridging two-molecule-electrode components, and 3) chemically bridging two-molecule-electrode components. Finally, the current state of molecular circuit integration and commercialization is discussed and perspectives are provided, hoping to encourage the community to accelerate the realization of fully scalable molecular electronics for a new era of integrated microsystems and applications.
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Affiliation(s)
- Tianming Li
- Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, 09126, Chemnitz, Germany
- Material Systems for Nanoelectronics, Chemnitz University of Technology, 09111, Chemnitz, Germany
| | - Vineeth Kumar Bandari
- Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, 09126, Chemnitz, Germany
- Material Systems for Nanoelectronics, Chemnitz University of Technology, 09111, Chemnitz, Germany
| | - Oliver G Schmidt
- Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, 09126, Chemnitz, Germany
- Material Systems for Nanoelectronics, Chemnitz University of Technology, 09111, Chemnitz, Germany
- Nanophysics, Dresden University of Technology, 01069, Dresden, Germany
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3
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Nguyen QV, Martin P, Lacroix JC. Probing the Effect of the Density of Active Molecules in Large-Area Molecular Junctions. J Phys Chem Lett 2022; 13:11990-11995. [PMID: 36537879 DOI: 10.1021/acs.jpclett.2c03027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The effect of the density of active molecules in molecular junctions (MJs) has been investigated by using a host/guest strategy. Mixed layers consisting of oligothiophene (BTB) encapsulated by β-cyclodextrin (BTB@β-CD) were generated. Cyclodextrins were then removed, and the pinholes generated were filled with BTB to obtain BTB@BTB films. MJs based on mixed BTB@β-CD and BTB@BTB layers, as well as single-component BTB MJs, were compared. The variation of ln J vs thickness is similar for all systems while the Jo of BTB@β-CD MJs is 20 times lower than that of BTB MJs. After β-cyclodextrin has been removed, and the pinholes filled, Jo increases and reaches the same value as for the BTB MJs, showing that the conductance scales with the number of active molecules. This strategy provides a unique method for investigating molecular interactions in direct tunneling MJs as well as the possibility of fabricating new functionalized MJs based on mixed layers.
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Affiliation(s)
- Quyen Van Nguyen
- Université Paris Cité, ITODYS, CNRS UMR 7086, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
- Department of Advanced Materials Science and Nanotechnology, University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, 11307 Cau Giay, Hanoi Vietnam
| | - Pascal Martin
- Université Paris Cité, ITODYS, CNRS UMR 7086, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Jean Christophe Lacroix
- Université Paris Cité, ITODYS, CNRS UMR 7086, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
- Department of Advanced Materials Science and Nanotechnology, University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, 11307 Cau Giay, Hanoi Vietnam
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Abstract
The field of molecular electronics has grown rapidly since its experimental realization in the late 1990s, with thousands of publications on how molecules can act as circuit components and the possibility of extending microelectronic miniaturization. Our research group developed molecular junctions (MJs) using conducting carbon electrodes and covalent bonding, which provide excellent temperature tolerance and operational lifetimes. A carbon-based MJ based on quantum mechanical tunneling for electronic music represents the world's first commercial application of molecular electronics, with >3000 units currently in consumer hands. The all-carbon MJ consisting of aromatic molecules and oligomers between vapor-deposited carbon electrodes exploits covalent, C-C bonding which avoids the electromigration problem of metal contacts. The high bias and temperature stability as well as partial transparency of the all-carbon MJ permit a wide range of experiments to determine charge transport mechanisms and observe photoeffects to both characterize and stimulate operating MJs. As shown in the Conspectus figure, our group has reported a variety of electronic functions, many of which do not have analogs in conventional semiconductors. Much of the described research is oriented toward the rational design of electronic functions, in which electronic characteristics are determined by molecular structure.In addition to the fabrication of molecular electronic devices with sufficient stability and operating life for practical applications, our approach was directed at two principal questions: how do electrons move through molecules that are components of an electronic circuit, and what can we do with molecules that we cannot do with existing semiconductor technology? The central component is the molecular junction consisting of a 1-20+ nm layer of covalently bonded oligomers between two electrodes of conducting, mainly sp2-hybridized carbon. In addition to describing the unique junction structure and fabrication methods, this Account summarizes the valuable insights available from photons used both as probes of device structure and dynamics and as prods to stimulate resonant transport through molecular orbitals.Short-range (<5 nm) transport by tunneling and its properties are discussed separately from the longer-range transport (5-60 nm) which bridges the gap between tunneling and transport in widely studied organic semiconductors. Most molecular electronic studies deal with the <5 nm thickness range, where coherent tunneling is generally accepted as the dominant transport mechanism. However, the rational design of devices in this range by changing molecular structure is frustrated by electronic interactions with the conducting contacts, resulting in weak structural effects on electronic behavior. When the molecular layer thickness exceeds 5 nm, transport characteristics change completely since molecular orbitals become the conduits for transport. Incident photons can stimulate transport, with the observed photocurrent tracking the absorption spectrum of the molecular layer. Low-temperature, activationless transport of photogenerated carriers is possible for up to at least 60 nm, with characteristics completely distinct from coherent tunneling and from the hopping mechanisms proposed for organic semiconductors. The Account closes with examples of phenomena and applications enabled by molecular electronics which may augment conventional microelectronics with chemical functions such as redox charge storage, orbital transport, and energy-selective photodetection.
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Affiliation(s)
- Richard L McCreery
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
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Shin J, Eo JS, Jeon T, Lee T, Wang G. Advances of Various Heterogeneous Structure Types in Molecular Junction Systems and Their Charge Transport Properties. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202399. [PMID: 35975456 PMCID: PMC9596861 DOI: 10.1002/advs.202202399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/11/2022] [Indexed: 05/31/2023]
Abstract
Molecular electronics that can produce functional electronic circuits using a single molecule or molecular ensemble remains an attractive research field because it not only represents an essential step toward realizing ultimate electronic device scaling but may also expand our understanding of the intrinsic quantum transports at the molecular level. Recently, in order to overcome the difficulties inherent in the conventional approach to studying molecular electronics and developing functional device applications, this field has attempted to diversify the electrical characteristics and device architectures using various types of heterogeneous structures in molecular junctions. This review summarizes recent efforts devoted to functional devices with molecular heterostructures. Diverse molecules and materials can be combined and incorporated in such two- and three-terminal heterojunction structures, to achieve desirable electronic functionalities. The heterojunction structures, charge transport mechanisms, and possible strategies for implementing electronic functions using various hetero unit materials are presented sequentially. In addition, the applicability and merits of molecular heterojunction structures, as well as the anticipated challenges associated with their implementation in device applications are discussed and summarized. This review will contribute to a deeper understanding of charge transport through molecular heterojunction, and it may pave the way toward desirable electronic functionalities in molecular electronics applications.
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Affiliation(s)
- Jaeho Shin
- KU‐KIST Graduate School of Converging Science and TechnologyKorea UniversitySeoul02841Korea
- Department of ChemistryRice University6100 Main StreetHoustonTexas77005United States
| | - Jung Sun Eo
- KU‐KIST Graduate School of Converging Science and TechnologyKorea UniversitySeoul02841Korea
| | - Takgyeong Jeon
- KU‐KIST Graduate School of Converging Science and TechnologyKorea UniversitySeoul02841Korea
| | - Takhee Lee
- Department of Physics and AstronomyInstitute of Applied PhysicsSeoul National UniversitySeoul08826Korea
| | - Gunuk Wang
- KU‐KIST Graduate School of Converging Science and TechnologyKorea UniversitySeoul02841Korea
- Department of Integrative Energy EngineeringKorea UniversitySeoul02841Korea
- Center for Neuromorphic EngineeringKorea Institute of Science and TechnologySeoul02792Korea
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6
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Plasmonic phenomena in molecular junctions: principles and applications. Nat Rev Chem 2022; 6:681-704. [PMID: 37117494 DOI: 10.1038/s41570-022-00423-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2022] [Indexed: 11/08/2022]
Abstract
Molecular junctions are building blocks for constructing future nanoelectronic devices that enable the investigation of a broad range of electronic transport properties within nanoscale regions. Crossing both the nanoscopic and mesoscopic length scales, plasmonics lies at the intersection of the macroscopic photonics and nanoelectronics, owing to their capability of confining light to dimensions far below the diffraction limit. Research activities on plasmonic phenomena in molecular electronics started around 2010, and feedback between plasmons and molecular junctions has increased over the past years. These efforts can provide new insights into the near-field interaction and the corresponding tunability in properties, as well as resultant plasmon-based molecular devices. This Review presents the latest advancements of plasmonic resonances in molecular junctions and details the progress in plasmon excitation and plasmon coupling. We also highlight emerging experimental approaches to unravel the mechanisms behind the various types of light-matter interactions at molecular length scales, where quantum effects come into play. Finally, we discuss the potential of these plasmonic-electronic hybrid systems across various future applications, including sensing, photocatalysis, molecular trapping and active control of molecular switches.
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7
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Gupta R, Jash P, Sachan P, Bayat A, Singh V, Mondal PC. Electrochemical Potential‐Driven High‐Throughput Molecular Electronic and Spintronic Devices: From Molecules to Applications. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202104724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ritu Gupta
- Department of Chemistry Indian Institute of Technology Kanpur Uttar Pradesh 208016 India
| | - Priyajit Jash
- Department of Chemistry Indian Institute of Technology Kanpur Uttar Pradesh 208016 India
| | - Pradeep Sachan
- Department of Chemistry Indian Institute of Technology Kanpur Uttar Pradesh 208016 India
| | - Akhtar Bayat
- Laboratoire Photonique Numérique et Nanosciences, UMR 5298 Université de Bordeaux 33400 Talence France
| | - Vikram Singh
- Department of Chemistry and National Science Research Institute Korea Advanced Institute of Science and Technology 291 Daehak-ro, Yuseong-gu Daejeon 34141 Republic of Korea
| | - Prakash Chandra Mondal
- Department of Chemistry Indian Institute of Technology Kanpur Uttar Pradesh 208016 India
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8
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Gupta R, Jash P, Sachan P, Bayat A, Singh V, Mondal PC. Electrochemical Potential-Driven High-Throughput Molecular Electronic and Spintronic Devices: From Molecules to Applications. Angew Chem Int Ed Engl 2021; 60:26904-26921. [PMID: 34313372 DOI: 10.1002/anie.202104724] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Indexed: 01/25/2023]
Abstract
Molecules are fascinating candidates for constructing tunable and electrically conducting devices by the assembly of either a single molecule or an ensemble of molecules between two electrical contacts followed by current-voltage (I-V) analysis, which is often termed "molecular electronics". Recently, there has been also an upsurge of interest in spin-based electronics or spintronics across the molecules, which offer additional scope to create ultrafast responsive devices with less power consumption and lower heat generation using the intrinsic spin property rather than electronic charge. Researchers have been exploring this idea of utilizing organic molecules, organometallics, coordination complexes, polymers, and biomolecules (proteins, enzymes, oligopeptides, DNA) in integrating molecular electronics and spintronics devices. Although several methods exist to prepare molecular thin-films on suitable electrodes, the electrochemical potential-driven technique has emerged as highly efficient. In this Review we describe recent advances in the electrochemical potential driven growth of nanometric various molecular films on technologically relevant substrates, including non-magnetic and magnetic electrodes to investigate the stimuli-responsive charge and spin transport phenomena.
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Affiliation(s)
- Ritu Gupta
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, 208016, India
| | - Priyajit Jash
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, 208016, India
| | - Pradeep Sachan
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, 208016, India
| | - Akhtar Bayat
- Laboratoire Photonique Numérique et Nanosciences, UMR 5298, Université de Bordeaux, 33400, Talence, France
| | - Vikram Singh
- Department of Chemistry and National Science Research Institute, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Prakash Chandra Mondal
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, 208016, India
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9
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Gorenskaia E, Turner KL, Martín S, Cea P, Low PJ. Fabrication of metallic and non-metallic top electrodes for large-area molecular junctions. NANOSCALE 2021; 13:9055-9074. [PMID: 34042128 DOI: 10.1039/d1nr00917f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Molecular junctions have proven invaluable tools through which to explore the electronic properties of molecules and molecular monolayers. In seeking to develop a viable molecular electronics based technology it becomes essential to be able to reliably create larger area molecular junctions by contacting molecular monolayers to both bottom and top electrodes. The assembly of monolayers onto a conducting substrate by self-assembly, Langmuir-Blodgett and other methods is well established. However, the deposition of top-contact electrodes without film penetration or damage from the growing electrode material has proven problematic. This Review highlights the challenges of this area, and presents a selective overview of methods that have been used to solve these issues.
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Affiliation(s)
- Elena Gorenskaia
- School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
| | - Kelly L Turner
- School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
| | - Santiago Martín
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain and Departamento de Química Física, Facultad de Ciencias, Universidad de Zaragoza, 50009, Zaragoza, Spain and Laboratorio de Microscopias Avanzadas (LMA). Universidad de Zaragoza, Edificio I+D+i. 50018, Zaragoza, Spain
| | - Pilar Cea
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain and Departamento de Química Física, Facultad de Ciencias, Universidad de Zaragoza, 50009, Zaragoza, Spain and Laboratorio de Microscopias Avanzadas (LMA). Universidad de Zaragoza, Edificio I+D+i. 50018, Zaragoza, Spain
| | - Paul J Low
- School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
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10
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Saxena SK, Tefashe UM, Supur M, McCreery RL. Evaluation of Carbon Based Molecular Junctions as Practical Photosensors. ACS Sens 2021; 6:513-522. [PMID: 33315386 DOI: 10.1021/acssensors.0c02183] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molecular junctions with partially transparent top contacts permit monitoring photocurrents as probes of transport mechanism and potentially could act as photosensors with characteristics determined by the molecular layer inside the device. Previously reported molecular junctions containing nitroazobenzene (NAB) oligomers and oligomers of two different aromatic molecules in bilayers were evaluated for sensitivity, dark signal, responsivity, and limits of detection, in order to determine the device parameters which have the largest effects on photodetection performance. The long-range transport of photogenerated charge carriers permits the use of molecular layers thick enough to absorb a large fraction of the light incident on the layer. Thick layers also reduce the dark current and its associated noise, thus improving the limit of detection to a few nanowatts on a detector area of 0.00125 cm2. Since the photocurrents have much lower activation energy than dark currents do, lowering the detector temperature significantly improves the limit of detection, although the present experiments were limited by environmental and instrumentation noise rather than detector noise. The highest specific detectivity (D*) for the current molecular devices was 3 × 107 cm s1/2 /W (∼109, if only shot noise is considered) at 407 nm in a carbon/NAB/carbon junction with a molecular layer thickness of 28 nm. Although this is in the low end of the 106-1012 range for commonly used photodetectors, improvements in device design based on the current results should increase D* by 3-4 orders of magnitude, while preserving the wavelength selectivity and tunability associated with molecular absorbers. In addition, operation outside the 300-1000 nm range of silicon detectors and very low dark currents may be possible with molecular junctions.
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Affiliation(s)
- Shailendra K. Saxena
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton, Alberta T6G 2G2, Canada
| | - Ushula M. Tefashe
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton, Alberta T6G 2G2, Canada
| | - Mustafa Supur
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton, Alberta T6G 2G2, Canada
| | - Richard L. McCreery
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton, Alberta T6G 2G2, Canada
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11
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Jarošová R, Bhardwaj K, Swain GM. Temperature dependence of the heterogeneous electron-transfer rate constant for ferrocene carboxylic acid in room temperature ionic liquids at microstructurally distinct carbon electrodes. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.114744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Nanofabrication Techniques in Large-Area Molecular Electronic Devices. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10176064] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The societal impact of the electronics industry is enormous—not to mention how this industry impinges on the global economy. The foreseen limits of the current technology—technical, economic, and sustainability issues—open the door to the search for successor technologies. In this context, molecular electronics has emerged as a promising candidate that, at least in the short-term, will not likely replace our silicon-based electronics, but improve its performance through a nascent hybrid technology. Such technology will take advantage of both the small dimensions of the molecules and new functionalities resulting from the quantum effects that govern the properties at the molecular scale. An optimization of interface engineering and integration of molecules to form densely integrated individually addressable arrays of molecules are two crucial aspects in the molecular electronics field. These challenges should be met to establish the bridge between organic functional materials and hard electronics required for the incorporation of such hybrid technology in the market. In this review, the most advanced methods for fabricating large-area molecular electronic devices are presented, highlighting their advantages and limitations. Special emphasis is focused on bottom-up methodologies for the fabrication of well-ordered and tightly-packed monolayers onto the bottom electrode, followed by a description of the top-contact deposition methods so far used.
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Saxena SK, Tefashe UM, McCreery RL. Photostimulated Near-Resonant Charge Transport over 60 nm in Carbon-Based Molecular Junctions. J Am Chem Soc 2020; 142:15420-15430. [DOI: 10.1021/jacs.0c06764] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shailendra K. Saxena
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Ushula M. Tefashe
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Richard L. McCreery
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
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14
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Nguyen TP, McCreery RL, McDermott MT. Evaluation of the electroanalytical performance of carbon-on-gold films prepared by electron-beam evaporation. Analyst 2020; 145:5041-5052. [PMID: 32555909 DOI: 10.1039/d0an00409j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon film electrodes can often be used without pretreatment, and their fabrication allows for flexibility in size and shape and for mass production. In this work, we are exploring layered structures comprised of thin films of carbon on gold (eC/Au) prepared by electron-beam evaporation. These extremely flat films are not pyrolyzed and are comprised of mainly amorphous carbon but still exhibit reasonable conductivity due to the underlying gold layer. eC/Au electrodes, without any pretreatment, yield similar heterogeneous electron-transfer rates for benchmark redox systems and significantly lower background current in comparison with polished glassy carbon. Interestingly, they show insignificant adsorption of quinones, which is uncommon for most carbon electrode materials. However, eC/Au is still prone to adsorption of airborne hydrocarbons when exposed to ambient air like most graphitic materials. With reproducibly fast electron transfer kinetics, low background current, negligible adsorption, and ultraflat surface, eC/Au films are a promising candidate for electrochemical and sensor applications.
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Affiliation(s)
- Thuy P Nguyen
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2N4, Canada.
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15
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Supur M, Saxena SK, McCreery RL. Ion-Assisted Resonant Injection and Charge Storage in Carbon-Based Molecular Junctions. J Am Chem Soc 2020; 142:11658-11662. [DOI: 10.1021/jacs.0c03943] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mustafa Supur
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| | - Shailendra K. Saxena
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
| | - Richard L. McCreery
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2R3, Canada
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16
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Karuppannan S, Neoh EHL, Vilan A, Nijhuis CA. Protective Layers Based on Carbon Paint To Yield High-Quality Large-Area Molecular Junctions with Low Contact Resistance. J Am Chem Soc 2020; 142:3513-3524. [PMID: 31951129 PMCID: PMC7307901 DOI: 10.1021/jacs.9b12424] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Indexed: 12/20/2022]
Abstract
A major obstacle for transforming large-area molecular junctions into a viable technology is the deposition of a top, metallic contact over the self-assembled monolayer (SAM) without chemically damaging the molecules and preventing an interface-limited charge transport. Often a thin conducting layer is softly deposited over the SAM to protect it during the deposition of the metal electrode which requires conditions under which organic molecules are not stable. We report a new protective layer based on carbon paint which is highly conductive and has metallic-like behavior. Junctions made of SAMs of n-alkanethiolates supported by Au were characterized with both dc and ac techniques, revealing that carbon paint protective layers provide a solution to three well-known challenges in molecular junctions: series resistance of the leads, poor interface conductance, and low effective contact area related to the roughness of the interfaces. Transport is constant with coherent tunneling down to 10 K, indicating the carbon paint does not add spurious thermally activated components. The junctions have both high reproducibility and good stability against bias stressing. Finally, normalized differential conductance analysis of the tunneling characteristics of the junctions as a function of molecular length reveals that the scaling voltage changes with molecular length, indicating a significant voltage drop on the molecules rather than on the molecule-electrode interface. There is a clear inverse dependence of the scaling voltage on length, which we deduced has a tunneling barrier height of close to 2 eV. The paper establishes the reliability of carbon paint protective layers and provides a procedure for discriminating genuine molecular effects from interfacial contributions.
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Affiliation(s)
- Senthil
Kumar Karuppannan
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Esther Hui Lin Neoh
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Ayelet Vilan
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, Rehovot 76100, Israel
| | - Christian A. Nijhuis
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- Centre
for Advanced 2D Materials, National University
of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
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17
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Sachan P, Mondal PC. Versatile electrochemical approaches towards the fabrication of molecular electronic devices. Analyst 2020; 145:1563-1582. [DOI: 10.1039/c9an01948k] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We highlight state-of-the-art electrochemical approaches for diazonium electroreduction on various electrodes that may be suitable for flexible molecular electronic junctions.
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Affiliation(s)
- Pradeep Sachan
- Department of Chemistry
- Indian Institute of Technology
- Kanpur
- India
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18
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Santos A, Tefashe UM, McCreery RL, Bueno PR. Introducing mesoscopic charge transfer rates into molecular electronics. Phys Chem Chem Phys 2020; 22:10828-10832. [DOI: 10.1039/d0cp01621g] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
It has been demonstrated that the concept of mesoscopic rate is able to establish a bridge between electrochemical and molecular electronic concepts.
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Affiliation(s)
- Adriano Santos
- Institute of Chemistry
- São Paulo State University (UNESP)
- Araraquara
- Brazil
| | | | | | - Paulo R. Bueno
- Institute of Chemistry
- São Paulo State University (UNESP)
- Araraquara
- Brazil
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19
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Najarian AM, McCreery RL. Long-Range Activationless Photostimulated Charge Transport in Symmetric Molecular Junctions. ACS NANO 2019; 13:867-877. [PMID: 30604970 DOI: 10.1021/acsnano.8b08662] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Molecular electronic junctions consisting of nitroazobenzene oligomers covalently bonded to a conducting carbon surface using an established "all-carbon" device design were illuminated with UV-vis light through a partially transparent top electrode. Monitoring junction conductance with a DC bias imposed permitted observation of photocurrents while varying the incident wavelength, light intensity, molecular layer thickness, and temperature. The photocurrent spectrum tracked the in situ absorption spectrum of nitroazobenzene, increased linearly with light intensity, and depended exponentially on applied bias. The electronic characteristics of the photocurrent differed dramatically from those of the same device in the dark, with orders of magnitude higher conductance and very weak attenuation with molecular layer thickness (β = 0.14 nm-1 for thickness above 5 nm). The temperature dependence of the photocurrent was opposite that of the dark current, with a 35% decrease in conductance between 80 and 450 K, while the dark current increased by a factor of 4.5 over the same range. The photocurrent was similar to the dark current for thin molecular layers but greatly exceeded the dark current for low bias and thick molecular layers. We conclude that the light and dark mechanisms are additive, with photoexcited carriers transported without thermal activation for a thickness range of 5-10 nm. The inverse temperature dependence is likely due to scattering or recombination events, both of which increase with temperature and in turn decrease the photocurrent. Photostimulated resonant transport potentially widens the breadth of conceivable molecular electronic devices and may have immediate value for wavelength-specific photodetection.
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Affiliation(s)
| | - Richard L McCreery
- Department of Chemistry , University of Alberta , Edmonton , Canada T6G 2R3
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20
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Hayashida M, Cui K, Najarian AM, McCreery R, Jehanathan N, Pawlowicz C, Motoki S, Kawasaki M, Konyuba Y, Malac M. Hole free phase plate tomography for materials sciences samples. Micron 2019; 116:54-60. [DOI: 10.1016/j.micron.2018.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 10/28/2022]
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21
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Chen R, Najarian AM, Kurapati N, Balla RJ, Oleinick A, Svir I, Amatore C, McCreery RL, Amemiya S. Self-Inhibitory Electron Transfer of the Co(III)/Co(II)-Complex Redox Couple at Pristine Carbon Electrode. Anal Chem 2018; 90:11115-11123. [PMID: 30118206 DOI: 10.1021/acs.analchem.8b03023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Applications of conducting carbon materials for highly efficient electrochemical energy devices require a greater fundamental understanding of heterogeneous electron-transfer (ET) mechanisms. This task, however, is highly challenging experimentally, because an adsorbing carbon surface may easily conceal its intrinsic reactivity through adventitious contamination. Herein, we employ nanoscale scanning electrochemical microscopy (SECM) and cyclic voltammetry to gain new insights into the interplay between heterogeneous ET and adsorption of a Co(III)/Co(II)-complex redox couple at the contamination-free surface of electron-beam-deposited carbon (eC). Specifically, we investigate the redox couple of tris(1,10-phenanthroline)cobalt(II), Co(phen)32+, as a promising mediator for dye-sensitized solar cells and redox flow batteries. A pristine eC surface overlaid with KCl is prepared in vacuum, protected from contamination in air, and exposed to an ultrapure aqueous solution of Co(phen)32+ by the dissolution of the protective KCl layer. We employ SECM-based nanogap voltammetry to quantitatively demonstrate that Co(phen)32+ is adsorbed on the pristine eC surface to electrostatically self-inhibit outer-sphere ET of nonadsorbed Co(phen)33+ and Co(phen)32+. Strong electrostatic repulsion among Co(phen)32+ adsorbates is also demonstrated by SECM-based nanogap voltammetry and cyclic voltammetry. Quantitatively, self-inhibitory ET is characterized by a linear decrease in the standard rate constant of Co(phen)32+ oxidation with a higher surface concentration of Co(phen)32+ at the formal potential. This unique relationship is consistent not with the Frumkin model of double layer effects, but with the Amatore model of partially blocked electrodes as extended for self-inhibitory ET. Significantly, the complicated coupling of electron transfer and surface adsorption is resolved by combining nanoscale and macroscale voltammetric methods.
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Affiliation(s)
- Ran Chen
- Department of Chemistry , University of Pittsburgh , 219 Parkman Avenue , Pittsburgh , Pennsylvania 15260 , United States
| | - Amin Morteza Najarian
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2R3 , Canada
| | - Niraja Kurapati
- Department of Chemistry , University of Pittsburgh , 219 Parkman Avenue , Pittsburgh , Pennsylvania 15260 , United States
| | - Ryan J Balla
- Department of Chemistry , University of Pittsburgh , 219 Parkman Avenue , Pittsburgh , Pennsylvania 15260 , United States
| | - Alexander Oleinick
- PASTEUR, Département de Chimie , École Normale Supérieure, PSL Université, Sorbonne Université , CNRS, 75005 Paris , France
| | - Irina Svir
- PASTEUR, Département de Chimie , École Normale Supérieure, PSL Université, Sorbonne Université , CNRS, 75005 Paris , France
| | - Christian Amatore
- PASTEUR, Département de Chimie , École Normale Supérieure, PSL Université, Sorbonne Université , CNRS, 75005 Paris , France.,State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering , Xiamen University , Xiamen , 361005 , China
| | - Richard L McCreery
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2R3 , Canada
| | - Shigeru Amemiya
- Department of Chemistry , University of Pittsburgh , 219 Parkman Avenue , Pittsburgh , Pennsylvania 15260 , United States
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22
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Meng L, Bian R, Guo C, Xu B, Liu H, Jiang L. Aligning Ag Nanowires by a Facile Bioinspired Directional Liquid Transfer: Toward Anisotropic Flexible Conductive Electrodes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1706938. [PMID: 29707831 DOI: 10.1002/adma.201706938] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 02/22/2018] [Indexed: 05/15/2023]
Abstract
Recent years have witnessed the booming development of transparent flexible electrodes (TFEs) for their applications in electronics and optoelectronic devices. Various strategies have thus been developed for preparing TFEs with higher flexibility and conductivity. However, little work has focused on TFEs with anisotropic conductivity. Here, a facile strategy of directional liquid transfer is proposed, guided by a conical fibers array (CFA), based on which silver nanowires (AgNWs) are aligned on a soft poly(ethylene terephthalate) substrate in large scale. After further coating a second thin layer of the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), a TFE with notable anisotropic conductivity and excellent optical transmittance of 95.2% is prepared. It is proposed that the CFA enables fine control over the receding of the three-phase contact line during the dewetting process, where AgNWs are guided and aligned by the as-generated directional stress. Moreover, anisotropic electrochemical deposition is enabled where the Cu nanoparticles deposit only on the oriented AgNWs, leading to a surface with anisotropic wetting behavior. Importantly, the approach enables alignment of AgNWs via multiple directions at one step. It is envisioned that the as-developed approach will provide an optional approach for simple and low-cost preparation of TFE with various functions.
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Affiliation(s)
- Lili Meng
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, No. 37 Xueyuan Road, Haidian district, Beijing, 100191, P. R. China
| | - Ruixin Bian
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, No. 37 Xueyuan Road, Haidian district, Beijing, 100191, P. R. China
| | - Cheng Guo
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, No. 37 Xueyuan Road, Haidian district, Beijing, 100191, P. R. China
| | - Bojie Xu
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, No. 37 Xueyuan Road, Haidian district, Beijing, 100191, P. R. China
| | - Huan Liu
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, No. 37 Xueyuan Road, Haidian district, Beijing, 100191, P. R. China
- Beijing Advanced Innovation Center for Biomedical Engineering and International Research Institute for Multidisciplinary Science, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, 100191, P. R. China
| | - Lei Jiang
- Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, No. 37 Xueyuan Road, Haidian district, Beijing, 100191, P. R. China
- Beijing Advanced Innovation Center for Biomedical Engineering and International Research Institute for Multidisciplinary Science, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, 100191, P. R. China
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23
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Xie Z, Bâldea I, Frisbie CD. Why one can expect large rectification in molecular junctions based on alkane monothiols and why rectification is so modest. Chem Sci 2018; 9:4456-4467. [PMID: 29896387 PMCID: PMC5956982 DOI: 10.1039/c8sc00938d] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/07/2018] [Indexed: 11/23/2022] Open
Abstract
Many attempts to obtain high current rectification ratios (RRs) in molecular electronics are triggered by a potentiometer rule argument, which predicts that a strongly asymmetric location of the dominant molecular orbital yields large RR-values. Invoking this argument, molecular junctions based on alkane monothiols (CnT) can be expected to exhibit high RRs; the HOMO of these molecules is localized on the thiol terminal group bonded to one electrode. The extensive current-voltage (I-V) results for CP-AFM (conducting probe atomic force microscope) CnT junctions of various molecular lengths (n = 7, 8, 9, 10, and 12) and different metallic contacts (Ag, Au, and Pt) are consistent with conduction dominated by the HOMO, but the measured RR ∼ 1.5 is much smaller than that predicted by the potentiometer rule framework. Further, the linear shift in the HOMO position with applied bias, γ, which gives rise to rectification, is also smaller than expected, and critically, γ has the opposite sign from potentiometer rule predictions. Companion ab initio OVGF (outer valence Green's function) quantum chemical calculations provide important insight. Namely, a linear Stark shift γm is calculated for the HOMO of CnT molecules for electric field strengths (106-107 V cm-1) typical of molecular junctions, and the sign of γm matches the sign of the experimental γ for junctions derived from transport measurements, suggesting that the Stark effect plays an important role. However, the magnitude of the measured γ is only 10-15% of the computed value γm. We propose that this implies that the contacts are far from optimal; they substantially screen the effect of the applied bias, possibly via molecule-electrode interface states. We predict that, with optimized contacts, the rectification ratios in CnT-based junctions can reach reasonably high values (RR ≈ 500). We believe that Stark shifts and limited current rectification due to non-ideal contacts discussed here for the specific case of alkane monothiol junctions are issues of general interest for molecular electronics that deserve further consideration.
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Affiliation(s)
- Zuoti Xie
- Department of Chemical Engineering and Materials Science , Department of Chemistry , University of Minnesota , Minneapolis , Minnesota 55455 , USA .
| | - Ioan Bâldea
- Theoretische Chemie , Universität Heidelberg , INF 229 , D-69120 Heidelberg , Germany .
| | - C Daniel Frisbie
- Department of Chemical Engineering and Materials Science , Department of Chemistry , University of Minnesota , Minneapolis , Minnesota 55455 , USA .
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24
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Chandra Mondal P, Tefashe UM, McCreery RL. Internal Electric Field Modulation in Molecular Electronic Devices by Atmosphere and Mobile Ions. J Am Chem Soc 2018; 140:7239-7247. [DOI: 10.1021/jacs.8b03228] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
| | - Ushula M. Tefashe
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Richard L. McCreery
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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25
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Morteza Najarian A, Bayat A, McCreery RL. Orbital Control of Photocurrents in Large Area All-Carbon Molecular Junctions. J Am Chem Soc 2018; 140:1900-1909. [DOI: 10.1021/jacs.7b12577] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Amin Morteza Najarian
- Department
of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G 2R3
- National
Institute for Nanotechnology, National Research Council Canada, Edmonton, Alberta, Canada, T6G 2G2
| | - Akhtar Bayat
- Department
of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G 2R3
- National
Institute for Nanotechnology, National Research Council Canada, Edmonton, Alberta, Canada, T6G 2G2
| | - Richard L. McCreery
- Department
of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G 2R3
- National
Institute for Nanotechnology, National Research Council Canada, Edmonton, Alberta, Canada, T6G 2G2
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26
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Steffenhagen M, Latus A, Trinh TMN, Nierengarten I, Lucas IT, Joiret S, Landoulsi J, Delavaux-Nicot B, Nierengarten JF, Maisonhaute E. A Rotaxane Scaffold Bearing Multiple Redox Centers: Synthesis, Surface Modification and Electrochemical Properties. Chemistry 2018; 24:1701-1708. [PMID: 29207203 DOI: 10.1002/chem.201705245] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Indexed: 12/24/2022]
Abstract
A rotaxane scaffold incorporating two dithiolane anchoring units for the modification of gold surfaces has been functionalized with multiple copies of a redox unit, namely ferrocene. Surface modification has been first assessed at the single molecule level by atomic force microscopy (AFM) and scanning tunneling microscopy (STM) imaging, while tip enhanced Raman spectroscopy (TERS) provided the local vibrational signature of the ferrocenyl subunits of the rotaxanes grafted onto the gold surface. Finally, oxidation of the redox moieties within a rotaxane scaffold grafted onto gold microelectrodes has been investigated by ultrafast cyclic voltammetry. Intramolecular electron hopping is indeed extremely fast in this system. Moreover, the kinetics of charge injection depends on the molecular coverage due to the influence of intermolecular contacts on molecular motions.
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Affiliation(s)
- Marie Steffenhagen
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8235, Laboratoire Interfaces et Systèmes Electrochimiques, 75005, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, UMR 7197, Laboratoire de Réactivité de Surfaces, 75005, Paris, France
| | - Alina Latus
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8235, Laboratoire Interfaces et Systèmes Electrochimiques, 75005, Paris, France
| | - Thi Minh Nguyet Trinh
- Laboratoire de Chimie des Matériaux Moléculaires, Université de Strasbourg et CNRS (UMR 7509), Ecole Européenne de Chimie, Polymères et Matériaux, 25 rue Becquerel, 67087, Strasbourg Cedex 2, France
| | - Iwona Nierengarten
- Laboratoire de Chimie des Matériaux Moléculaires, Université de Strasbourg et CNRS (UMR 7509), Ecole Européenne de Chimie, Polymères et Matériaux, 25 rue Becquerel, 67087, Strasbourg Cedex 2, France
| | - Ivan T Lucas
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8235, Laboratoire Interfaces et Systèmes Electrochimiques, 75005, Paris, France
| | - Suzanne Joiret
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8235, Laboratoire Interfaces et Systèmes Electrochimiques, 75005, Paris, France
| | - Jessem Landoulsi
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7197, Laboratoire de Réactivité de Surfaces, 75005, Paris, France
| | - Béatrice Delavaux-Nicot
- Laboratoire de Chimie de Coordination du CNRS (UPR 8241), Université de Toulouse (UPS, INPT), 205 route de Narbonne, BP 44099, 31077, Toulouse Cedex 4, France
| | - Jean-François Nierengarten
- Laboratoire de Chimie des Matériaux Moléculaires, Université de Strasbourg et CNRS (UMR 7509), Ecole Européenne de Chimie, Polymères et Matériaux, 25 rue Becquerel, 67087, Strasbourg Cedex 2, France
| | - Emmanuel Maisonhaute
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8235, Laboratoire Interfaces et Systèmes Electrochimiques, 75005, Paris, France
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27
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James DD, Bayat A, Smith SR, Lacroix JC, McCreery RL. Nanometric building blocks for robust multifunctional molecular junctions. NANOSCALE HORIZONS 2018; 3:45-52. [PMID: 32254109 DOI: 10.1039/c7nh00109f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Much of the motivation for developing molecular electronic devices is the prospect of achieving novel electronic functions by varying molecular structure. We describe a "building block" approach for molecular junctions resulting in one, two or three nanometer-thick molecular layers in a commercially proven junction design. A single layer of anthraquinone between carbon electrodes provides a tunnel device with applications in electronic music, and a second layer of a thiophene derivative yields a molecular rectifier with quite different audio characteristics. A third layer of lithium benzoate produces a redox-active device with possible applications in non-volatile memory devices or on-chip energy storage. The building block approach forms a basis for "rational design" of electronic functions, in which layers of varying structure produce distinct and desirable electronic behaviours.
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Affiliation(s)
- David D James
- National Institute for Nanotechnology, University of Alberta, 11421 Saskatchewan Dr Edmonton, AB T6G 2M9, Canada.
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28
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Morteza Najarian A, Chen R, Balla RJ, Amemiya S, McCreery RL. Ultraflat, Pristine, and Robust Carbon Electrode for Fast Electron-Transfer Kinetics. Anal Chem 2017; 89:13532-13540. [PMID: 29132207 DOI: 10.1021/acs.analchem.7b03903] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electron-beam (e-beam) deposition of carbon on a gold substrate yields a very flat (0.43 nm of root-mean-square roughness), amorphous carbon film consisting of a mixture of sp2- and sp3-hybridized carbon with sufficient conductivity to avoid ohmic potential error. E-beam carbon (eC) has attractive properties for conventional electrochemistry, including low background current and sufficient transparency for optical spectroscopy. A layer of KCl deposited by e-beam to the eC surface without breaking vacuum protects the surface from the environment after fabrication until dissolved by an ultrapure electrolyte solution. Nanogap voltammetry using scanning electrochemical microscopy (SECM) permits measurement of heterogeneous standard electron-transfer rate constants (k°) in a clean environment without exposure of the electrode surface to ambient air. The ultraflat eC surface permitted nanogap voltammetry with very thin electrode-to-substrate gaps, thus increasing the diffusion limit for k° measurement to >14 cm/s for a gap of 44 nm. Ferrocene trimethylammonium as the redox mediator exhibited a diffusion-limited k° for the previously KCl-protected eC surface, while k° was 1.45 cm/s for unprotected eC. The k° for Ru(NH3)63+/2+ increased from 1.7 cm/s for unprotected eC to above the measurable limit of 6.9 cm/s for a KCl-protected eC electrode.
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Affiliation(s)
- Amin Morteza Najarian
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2R3, Canada.,National Institute for Nanotechnology, National Research Council Canada , Edmonton, Alberta T6G 2G2, Canada
| | - Ran Chen
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Ryan J Balla
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Shigeru Amemiya
- Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Richard L McCreery
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2R3, Canada.,National Institute for Nanotechnology, National Research Council Canada , Edmonton, Alberta T6G 2G2, Canada
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29
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Meded V, Knorr N, Neumann T, Nelles G, Wenzel W, von Wrochem F. Structural origins of the cohesive energy in metal-terpyridine oligomer thin-films. Phys Chem Chem Phys 2017; 19:27952-27959. [PMID: 28949351 DOI: 10.1039/c7cp05488b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
FeII-terpyridine based oligomers have attracted considerable interest as key constituents for the realization of highly robust, ultra-thin ordered layers of metal center oligomers (MCOs) for organic electronics applications. By using molecular simulations and nanotribology investigations, we report on the origins of the surprisingly high mechanical and thermal stability in this type of MCO layers, which finds its expression in nanowear resistance values of up to 1.5 μN for the MCO films, as well as in a thermal stability of two-terminal MCO junctions to temperatures up to ∼100 °C under electrical load. A theoretical analysis of the fundamental cohesive forces among the constituents within the context of an electrostatic model reveal that the cohesive energy is essentially based on Coulomb interactions among the ionic constituents of the oligomers, leading to an estimated cohesive energy per molar mass of 0.0132 eV mol g-1 for MCO layers that advantageously compare to the 0.0061 eV mol g-1 reported for pentacene crystals.
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Affiliation(s)
- Velimir Meded
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany.
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30
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Nguyen QV, Martin P, Frath D, Della Rocca ML, Lafolet F, Barraud C, Lafarge P, Mukundan V, James D, McCreery RL, Lacroix JC. Control of Rectification in Molecular Junctions: Contact Effects and Molecular Signature. J Am Chem Soc 2017; 139:11913-11922. [DOI: 10.1021/jacs.7b05732] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Quyen van Nguyen
- Université Paris Diderot, Sorbonne Paris
Cité, ITODYS, UMR 7086 CNRS, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
- Department
of Advanced Materials Science and Nanotechnology, University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
| | - Pascal Martin
- Université Paris Diderot, Sorbonne Paris
Cité, ITODYS, UMR 7086 CNRS, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Denis Frath
- Université Paris Diderot, Sorbonne Paris
Cité, ITODYS, UMR 7086 CNRS, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Maria Luisa Della Rocca
- Laboratoire
Matériaux et Phénomènes Quantiques (MPQ), Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France
| | - Frederic Lafolet
- Université Paris Diderot, Sorbonne Paris
Cité, ITODYS, UMR 7086 CNRS, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Clément Barraud
- Laboratoire
Matériaux et Phénomènes Quantiques (MPQ), Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France
| | - Philippe Lafarge
- Laboratoire
Matériaux et Phénomènes Quantiques (MPQ), Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex 13, France
| | - Vineetha Mukundan
- University of Alberta, National Institute
for Nanotechnology, 11421
Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
| | - David James
- University of Alberta, National Institute
for Nanotechnology, 11421
Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
| | - Richard L. McCreery
- University of Alberta, National Institute
for Nanotechnology, 11421
Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
| | - Jean-Christophe Lacroix
- Université Paris Diderot, Sorbonne Paris
Cité, ITODYS, UMR 7086 CNRS, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
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31
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Jeong H, Kim D, Xiang D, Lee T. High-Yield Functional Molecular Electronic Devices. ACS NANO 2017; 11:6511-6548. [PMID: 28578582 DOI: 10.1021/acsnano.7b02967] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An ultimate goal of molecular electronics, which seeks to incorporate molecular components into electronic circuit units, is to generate functional molecular electronic devices using individual or ensemble molecules to fulfill the increasing technical demands of the miniaturization of traditional silicon-based electronics. This review article presents a summary of recent efforts to pursue this ultimate aim, covering the development of reliable device platforms for high-yield ensemble molecular junctions and their utilization in functional molecular electronic devices, in which distinctive electronic functionalities are observed due to the functional molecules. In addition, other aspects pertaining to the practical application of molecular devices such as manufacturing compatibility with existing complementary metal-oxide-semiconductor technology, their integration, and flexible device applications are also discussed. These advances may contribute to a deeper understanding of charge transport characteristics through functional molecular junctions and provide a desirable roadmap for future practical molecular electronics applications.
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Affiliation(s)
- Hyunhak Jeong
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University , Seoul 08826, Korea
| | - Dongku Kim
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University , Seoul 08826, Korea
| | - Dong Xiang
- Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China
| | - Takhee Lee
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University , Seoul 08826, Korea
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32
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Supur M, Smith SR, McCreery RL. Characterization of Growth Patterns of Nanoscale Organic Films on Carbon Electrodes by Surface Enhanced Raman Spectroscopy. Anal Chem 2017; 89:6463-6471. [DOI: 10.1021/acs.analchem.7b00362] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Mustafa Supur
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Scott R. Smith
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Richard L. McCreery
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
- National
Institute for Nanotechnology, National Research Council Canada, 11421
Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
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33
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Tefashe UM, Nguyen QV, Lafolet F, Lacroix JC, McCreery RL. Robust Bipolar Light Emission and Charge Transport in Symmetric Molecular Junctions. J Am Chem Soc 2017; 139:7436-7439. [DOI: 10.1021/jacs.7b02563] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Ushula M. Tefashe
- Department
of Chemistry, University of Alberta, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
| | - Quyen Van Nguyen
- Université Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR
7086 CNRS, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Frederic Lafolet
- Université Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR
7086 CNRS, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Jean-Christophe Lacroix
- Université Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR
7086 CNRS, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Richard L. McCreery
- Department
of Chemistry, University of Alberta, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
- National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
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Morteza Najarian A, McCreery RL. Structure Controlled Long-Range Sequential Tunneling in Carbon-Based Molecular Junctions. ACS NANO 2017; 11:3542-3552. [PMID: 28238263 DOI: 10.1021/acsnano.7b00597] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Carbon-based molecular junctions consisting of aromatic oligomers between conducting sp2 hybridized carbon electrodes exhibit structure-dependent current densities (J) when the molecular layer thickness (d) exceeds ∼5 nm. All four of the molecular structures examined exhibit an unusual, nonlinear ln J vs bias voltage (V) dependence which is not expected for conventional coherent tunneling or activated hopping mechanisms. All molecules exhibit a weak temperature dependence, with J increasing typically by a factor of 2 over the range of 200-440 K. Fluorene and anthraquinone show linear plots of ln J vs d with nearly identical J values for the range d = 3-10 nm, despite significant differences in their free-molecule orbital energy levels. The observed current densities for anthraquinone, fluorene, nitroazobenzene, and bis-thienyl benzene for d = 7-10 nm show no correlation with occupied (HOMO) or unoccupied (LUMO) molecular orbital energies, contrary to expectations for transport mechanisms based on the offset between orbital energies and the electrode Fermi level. UV-vis absorption spectroscopy of molecular layers bonded to carbon electrodes revealed internal energy levels of the chemisorbed films and also indicated limited delocalization in the film interior. The observed current densities correlate well with the observed UV-vis absorption maxima for the molecular layers, implying a transport mechanism determined by the HOMO-LUMO energy gap. We conclude that transport in carbon-based aromatic molecular junctions is consistent with multistep tunneling through a barrier defined by the HOMO-LUMO gap, and not by charge transport at the electrode interfaces. In effect, interfacial "injection" at the molecule/electrode interfaces is not rate limiting due to relatively strong electronic coupling, and transport is controlled by the "bulk" properties of the molecular layer interior.
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Affiliation(s)
- Amin Morteza Najarian
- Department of Chemistry, University of Alberta , Edmonton,Alberta T6G 2R3, Canada
- National Institute for Nanotechnology, National Research Council Canada , Ottawa, Ontario T6G 2G2, Canada
| | - Richard L McCreery
- Department of Chemistry, University of Alberta , Edmonton,Alberta T6G 2R3, Canada
- National Institute for Nanotechnology, National Research Council Canada , Ottawa, Ontario T6G 2G2, Canada
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