1
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Nguyen AT, Louis-Goff T, Ortiz-Garcia JJ, Pham TKN, Quardokus RC, Lee EC, Brown JJ, Hyvl J, Lee W. Cluster Formation of Self-Assembled Triarylbismuthanes and Charge Transport Characterizations of Gold-Triarylbismuthane-Gold Junctions. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38981101 DOI: 10.1021/acsami.4c04294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Organometallic molecules are promising for molecular electronic devices due to their potential to improve electrical conductance through access to complex orbital covalency that is not available to light-element organic molecules. However, studies of the formation of organometallic monolayers and their charge transport properties are scarce. Here, we report the cluster formation and charge transport properties of gold-triarylbismuthane-gold molecular junctions. We found that triarylbismuthane molecules with -CN anchoring groups form clusters during the creation of self-assembled submonolayers. This clustering is attributed to strong interactions between the bismuth (Bi) center and the nitrogen atom in the -CN group of adjacent molecules. Examination of the influence of -NH2 and -CN anchoring groups on junction conductance revealed that, despite a stronger binding energy between the -NH2 group and gold, the conductance per molecular unit (i.e., molecule for the -NH2 group and cluster for the -CN group) is higher with the -CN anchoring group. Further analysis showed that an increase in the number of -CN groups from one to three within the junctions leads to a decrease in conductance while increasing the size of the cluster. This demonstrates the significant effects of different anchoring groups and the impact of varying the number of -CN groups on both the charge transport and cluster formation. This study highlights the importance of selecting the appropriate anchoring group in the design of molecular junctions. Additionally, controlling the size and formation of clusters can be a strategic approach to engineering charge transport in molecular junctions.
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Affiliation(s)
- Anh Tuan Nguyen
- Department of Mechanical Engineering, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
| | - Thomas Louis-Goff
- Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
| | - José J Ortiz-Garcia
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Thi Kieu Ngan Pham
- Department of Mechanical Engineering, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
| | - Rebecca C Quardokus
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Eun-Cheol Lee
- Department of Nanoscience and Technology, Graduate School and Department of Physics, Gachon University, Gyeonggi 13120, Republic of Korea
| | - Joseph J Brown
- Department of Mechanical Engineering, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
| | - Jakub Hyvl
- Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
| | - Woochul Lee
- Department of Mechanical Engineering, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
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2
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Hamedian A, Vakili M, Brandán SA, Akbari M, Kanaani A, Darugar V. Theoretical study on the structure, spectroscopic, and current-voltage behavior of 11-Cis and Trans retinal isomers in rhodopsin. Sci Rep 2024; 14:12452. [PMID: 38816529 PMCID: PMC11140004 DOI: 10.1038/s41598-024-63249-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 05/27/2024] [Indexed: 06/01/2024] Open
Abstract
In this study, the electronic transport properties of 11-Cis and Trans retinal, components of rhodopsin, were investigated as optical molecular switches using the nonequilibrium Green's function (NEGF) formalism combined with first-principles density functional theory (DFT). These isomers, which can be reversibly converted into each other, were examined in detail. The structural and spectroscopic properties, including infrared (IR), Raman, nuclear magnetic resonance (NMR), and ultraviolet (UV) spectra, were analyzed using the hybrid B3LYP/6-311 + + G** level of theory. Complete vibrational assignments were performed for both forms utilizing the scaled quantum mechanical force field (SQMFF) methodology. To evaluate the conductivity of these molecules, we utilized current-voltage (I-V) characteristics, transmission spectra, molecular projected self-consistent Hamiltonian (MPSH), HOMO-LUMO gap, and second-order interaction energies (E2). The trendline extrapolation of the current-voltage plots confirmed our findings. We investigated the effect of different electrodes (Ag, Au, Pt) and various connection sites (hollow, top, bridge) on conductivity. The Ag electrode with the hollow site exhibited the highest efficiency. Our results indicate that the Cis form has higher conductivity than the Trans form.
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Affiliation(s)
- Amin Hamedian
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, 91775-1436, Iran
| | - Mohammad Vakili
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, 91775-1436, Iran.
| | - Silvia A Brandán
- Cátedra de Química General, Instituto de Química, Inorgánica Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, 4000, Tucumán, Argentina
| | - Mahmood Akbari
- UNESCO‑UNISA-ITL Africa Chair in Nanoscience and Nanotechnology (U2ACN2), College of Graduate Studies, University of South Africa (UNISA), Pretoria, South Africa
| | - Ayoub Kanaani
- School of Chemistry, Damghan University, Damghan, 36716-41167, Iran
| | - Vahidreza Darugar
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, 91775-1436, Iran
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3
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Medhi B, Nath U, Sarma M. Revisiting fulgide photochromism: Mechanistic decoding and electron transport from computational exploration. J Chem Phys 2024; 160:154308. [PMID: 38634497 DOI: 10.1063/5.0203307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 04/01/2024] [Indexed: 04/19/2024] Open
Abstract
The photochromic behavior of the fulgide molecule relies on ring-closure and ring-opening processes involving conical intersections during excited state transformation between isomers. The precise location and topography of these conical intersections significantly shape the decay process and fluorescence phenomena inherent to the molecule. This work combines electronic structure theory calculations using the density functional theory and wavefunction methods, as well as surface hopping simulation to analyze the photochemical behavior of an experimentally synthesized fulgide molecule, (E)-p-methylacetophenylisopropylidenesuccinic anhydride (1E). Our study reveals the conical intersection between the first excited state (S1) and the ground electronic state (S0), which emerges beyond the S1 minimum of 1E to the ring-closing side. The distinctive topography of this conical intersection appears to be sloped. These findings suggest a reduced quantum yield for the formation of the closed isomer, indicating a higher likelihood of reformation of the open isomer(s). The surface hopping simulation further supports this observation, revealing a mere ∼8% quantum yield for the formation of the closed isomer. In addition, the photoisomerization of the fulgide molecule initiates a cascade of conduction switching and holds great potential for applications in molecular electronics. Delving into the realm of molecular electronics, we have further examined the electron transport properties, disclosing the higher conductivity of the closed isomer.
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Affiliation(s)
- Biman Medhi
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India
| | - Upasana Nath
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India
| | - Manabendra Sarma
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India
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4
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Ornago L, Zwick P, van der Poel S, Brandl T, El Abbassi M, Perrin ML, Dulić D, van der Zant HSJ, Mayor M. Influence of Peripheral Alkyl Groups on Junction Configurations in Single-Molecule Electronics. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2024; 128:1413-1422. [PMID: 38293692 PMCID: PMC10823531 DOI: 10.1021/acs.jpcc.3c06970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 12/28/2023] [Accepted: 12/28/2023] [Indexed: 02/01/2024]
Abstract
The addition of a lateral alkyl chain is a well-known strategy to reduce π-stacked ensembles of molecules in solution, with the intention to minimize the interactions between the molecules' backbones. In this paper, we study whether this concept generalizes to single-molecule junctions by using a combination of mechanically controllable break junction (MCBJ) measurements and clustering-based data analysis with two small series of model compounds decorated with various bulky groups. The systematic study suggests that introducing alkyl side chains also favors the formation of electrode-molecule configurations that are not observed in their absence, thereby inducing broadening of the conductance peak in the one-dimensional histograms. Thus, the introduction of alkyl chains in aromatic compounds for molecular electronics must be carefully designed and optimized for the specific purpose, balancing between increased solubility and the possibility of additional junction configurations.
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Affiliation(s)
- Luca Ornago
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Patrick Zwick
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Sebastiaan van der Poel
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Thomas Brandl
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Maria El Abbassi
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Mickael L. Perrin
- Transport
at Nanoscale Interfaces Laboratory, Empa,
Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
- Department
of Information Technology and Electrical Engineering, ETH Zürich, 8092 Zürich, Switzerland
- Quantum
Center, ETH Zürich, 8093 Zürich, Switzerland
| | - Diana Dulić
- Department
of Physics and Department of Electrical Engineering, Faculty of Physical
and Mathematical Sciences, University of
Chile, Avenida Blanco
Encalada 2008, Santiago 8330015, Chile
| | - Herre S. J. van der Zant
- Kavli
Institute of Nanoscience, Delft University
of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Marcel Mayor
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
- Institute
for Nanotechnology (INT), Karlsruhe Institute
of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe, Germany
- Lehn
Institute of Functional Materials (LIFM), School of Chemistry, Sun Yat-Sen University (SYSU), Guangzhou 510275, China
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5
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Kaur R, Kaur S, Randhawa DKK, Sharma R, Kaur P. Mechanism of rectification and negative differential resistance in single-molecule junctions with asymmetric anchoring groups: a DFT study. J Mol Model 2023; 29:340. [PMID: 37840050 DOI: 10.1007/s00894-023-05747-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 10/03/2023] [Indexed: 10/17/2023]
Abstract
CONTEXT This study aims to investigate the electronic transport properties of tetracene molecule connected to gold (Au) electrodes with asymmetric anchoring groups. More specifically, we investigate the effect of asymmetric electrode coupling on the rectification ratio of tetracene-based molecular device. To introduce coupling asymmetry in these junctions, one end of the tetracene molecule is terminated with thiol (-SH) or isocyanide (-NC) while the other end with amine (-NH2) or nitro (-NO2) anchoring group. The results indicate that the electronic transport behavior is affected by the nature of molecule-electrode coupling, and the rectification ratio can be modulated by a proper choice of the anchoring groups. We reveal that the tetracene molecule when connected with isocyanide and amine combination exhibits remarkable rectifying performance (with a rectification ratio of 74) in contrast with other configurations. Furthermore, a prominent negative differential resistance (NDR) feature is observed when the molecule is connected with thiol as one of the anchors. Our present findings with excellent rectifying performance and negative differential resistance pave a new roadmap for designing multifunctional molecular devices. METHODS By applying non-equilibrium Green's function (NEGF) formalism combined with density functional theory (DFT) Atomistic Tool Kit software package, the electronic transport properties of tetracene molecule connected to gold electrodes with asymmetric anchoring groups have been investigated. The calculations were performed using the Perdew-Burke-Ernzerhof (PBE) parameterization of DFT within generalized gradient approximation (GGA) exchange-correlation functional. To improve calculation precision and save computational efforts, the molecule and anchor groups were double-ζ (DZ) polarized, while single-ζ (SZ) polarized basis set was used for gold electrodes.
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Affiliation(s)
- Rupendeep Kaur
- Department of Electronics Technology, Guru Nanak Dev University, Amritsar, 143005, India
| | - Sukhdeep Kaur
- Department of Electronics Technology, Guru Nanak Dev University, Amritsar, 143005, India.
| | - Deep Kamal Kaur Randhawa
- Department of Engineering and Technology, Guru Nanak Dev University Regional Campus, Jalandhar, 144007, India
| | - Rahul Sharma
- Department of Electronics and Communication Engineering, Lovely Professional University, Phagwara, 144411, India
| | - Pawandeep Kaur
- Department of Electronics Technology, Guru Nanak Dev University, Amritsar, 143005, India
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6
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First-principle study of the current–voltage on the β-diketones with alkyl and methoxy groups at the beta position as molecular switches. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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7
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Alam S, Augustine S, Narayan T, Luong JHT, Malhotra BD, Khare SK. A Chemosensor Based on Gold Nanoparticles and Dithiothreitol (DTT) for Acrylamide Electroanalysis. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2610. [PMID: 34685051 PMCID: PMC8540553 DOI: 10.3390/nano11102610] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 09/22/2021] [Accepted: 10/01/2021] [Indexed: 02/01/2023]
Abstract
Rapid and simple electroanalysis of acrylamide (ACR) was feasible by a gold electrode modified with gold nanoparticles (AuNPs) and dithiothreitol (DTT) with enhanced detection sensitivity and selectivity. The roughness of bare gold (Au) increased from 0.03 μm to 0.04 μm when it was decorated with AuNPs. The self-assembly between DTT and AuNPs resulted in a surface roughness of 0.09 μm. The DTT oxidation occurred at +0.92 V. The Au/AuNPs/DTT surface exhibited a surface roughness of 0.24 μm after its exposure to ACR with repeated analysis. SEM imaging illustrated the formation of a polymer layer on the Au/AuNPs/DTT surface. Surface plasmon resonance analysis confirmed the presence of AuNPs and DTT on the gold electrode and the binding of ACR to the electrode's active surface area. The peak area obtained by differential pulse voltammetry was inversely proportional to the ACR concentrations. The limit of detection (LOD) and the limit of quantitation (LOQ) were estimated to be 3.11 × 10-9 M and 1 × 10-8 M, respectively, with wide linearity ranging from 1 × 10-8 M to 1 × 10-3 M. The estimated levels of ACR in potato chips and coffee samples by the sensor were in agreement with those of high-performance liquid chromatography.
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Affiliation(s)
- Shahenvaz Alam
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India;
| | - Shine Augustine
- Nanobioelectronic Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana, New Delhi 110042, India; (S.A.); (T.N.); (B.D.M.)
| | - Tarun Narayan
- Nanobioelectronic Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana, New Delhi 110042, India; (S.A.); (T.N.); (B.D.M.)
| | - John H. T. Luong
- School of Chemistry, University College Cork, T12 YN60 Cork, Ireland; or
| | - Bansi Dhar Malhotra
- Nanobioelectronic Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana, New Delhi 110042, India; (S.A.); (T.N.); (B.D.M.)
| | - Sunil K. Khare
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India;
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8
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Zwick P, Dulić D, van der Zant HSJ, Mayor M. Porphyrins as building blocks for single-molecule devices. NANOSCALE 2021; 13:15500-15525. [PMID: 34558586 PMCID: PMC8485416 DOI: 10.1039/d1nr04523g] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 08/19/2021] [Indexed: 05/23/2023]
Abstract
Direct measurement of single-molecule electrical transparency by break junction experiments has become a major field of research over the two last decades. This review specifically and comprehensively highlights the use of porphyrins as molecular components and discusses their potential use for the construction of future devices. Throughout the review, the features provided by porphyrins, such as low level misalignments and very low attenuation factors, are shown with numerous examples, illustrating the potential and limitations of these molecular junctions, as well as differences emerging from applied integration/investigation techniques.
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Affiliation(s)
- Patrick Zwick
- Department of Chemistry, University of Basel, St Johanns-Ring 19, 4056 Basel, Switzerland.
| | - Diana Dulić
- Department of Physics and Department of Electrical Engineering, Faculty of Physical and Mathematical Sciences, University of Chile, Avenida Blanco Encalada 2008, Santiago 8330015, Chile
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Marcel Mayor
- Department of Chemistry, University of Basel, St Johanns-Ring 19, 4056 Basel, Switzerland.
- Institute for Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), P. O. Box 3640, 76021 Karlsruhe, Germany
- Lehn Institute of Functional Materials (LIFM), School of Chemistry, Sun Yat-Sen University (SYSU), 510275 Guangzhou, China
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9
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Darugar V, Vakili M, Tayyari SF. Voltage–current behavior of 4-phenylamino-3-penten-2-one and its derivatives molecular switch: a first-principles study. MOLECULAR SIMULATION 2021. [DOI: 10.1080/08927022.2021.1917767] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Vahidreza Darugar
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Mohammad Vakili
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
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10
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Wang X, Ismael A, Almutlg A, Alshammari M, Al-Jobory A, Alshehab A, Bennett TLR, Wilkinson LA, Cohen LF, Long NJ, Robinson BJ, Lambert C. Optimised power harvesting by controlling the pressure applied to molecular junctions. Chem Sci 2021; 12:5230-5235. [PMID: 34163759 PMCID: PMC8179551 DOI: 10.1039/d1sc00672j] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 02/22/2021] [Indexed: 11/21/2022] Open
Abstract
A major potential advantage of creating thermoelectric devices using self-assembled molecular layers is their mechanical flexibility. Previous reports have discussed the advantage of this flexibility from the perspective of facile skin attachment and the ability to avoid mechanical deformation. In this work, we demonstrate that the thermoelectric properties of such molecular devices can be controlled by taking advantage of their mechanical flexibility. The thermoelectric properties of self-assembled monolayers (SAMs) fabricated from thiol terminated molecules were measured with a modified AFM system, and the conformation of the SAMs was controlled by regulating the loading force between the organic thin film and the probe, which changes the tilt angle at the metal-molecule interface. We tracked the thermopower shift vs. the tilt angle of the SAM and showed that changes in both the electrical conductivity and Seebeck coefficient combine to optimize the power factor at a specific angle. This optimization of thermoelectric performance via applied pressure is confirmed through the use of theoretical calculations and is expected to be a general method for optimising the power factor of SAMs.
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Affiliation(s)
- Xintai Wang
- Physics Department, Lancaster University Lancaster LA1 4YB UK
- The Blackett Laboratory, Imperial College London, South Kensington Campus London SW7 2AZ UK
| | - Ali Ismael
- Physics Department, Lancaster University Lancaster LA1 4YB UK
- Department of Physics, College of Education for Pure Science, Tikrit University Tikrit Iraq
| | - Ahmad Almutlg
- Physics Department, Lancaster University Lancaster LA1 4YB UK
| | | | - Alaa Al-Jobory
- Physics Department, Lancaster University Lancaster LA1 4YB UK
- Department of Physics, College of Science, University of Anbar Anbar Iraq
| | | | - Troy L R Bennett
- Department of Chemistry, Imperial College London, MSRH White City London W12 0BZ UK
| | - Luke A Wilkinson
- Department of Chemistry, Imperial College London, MSRH White City London W12 0BZ UK
- Department of Chemistry, University of York Heslington York YO10 5DD UK
| | - Lesley F Cohen
- The Blackett Laboratory, Imperial College London, South Kensington Campus London SW7 2AZ UK
| | - Nicholas J Long
- Department of Chemistry, Imperial College London, MSRH White City London W12 0BZ UK
| | | | - Colin Lambert
- Physics Department, Lancaster University Lancaster LA1 4YB UK
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11
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Balliou A, Bouroushian M, Douvas AM, Skoulatakis G, Kennou S, Glezos N. Size-dependent single electron transfer and semi-metal-to-insulator transitions in molecular metal oxide electronics. NANOTECHNOLOGY 2018; 29:275204. [PMID: 29648551 DOI: 10.1088/1361-6528/aabdc3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
All-inorganic self-arranged molecular transition metal oxide hyperstructures based on polyoxometalate molecules (POMs) are fabricated and tested as electronically tunable components in emerging electronic devices. POM hyperstructures reveal great potential as charging nodes of tunable charging level for molecular memories and as enhancers of interfacial electron/hole injection for photovoltaic stacks. STM, UPS, UV-vis spectroscopy and AFM measurements show that this functionality stems from the films' ability to structurally tune their HOMO-LUMO levels and electron localization length at room temperature. By adapting POM nanocluster size in solution, self-doping and current modulation of four orders of magnitude is monitored on a single nanocluster on SiO2 at voltages as low as 3 Volt. Structurally driven insulator-to-semi-metal transitions and size-dependent current regulation through single electron tunneling are demonstrated and examined with respect to the stereochemical and electronic structure of the molecular entities. This extends the value of self-assembly as a tool for correlation length and electronic properties tuning and demonstrate POM hyperstructures' plausibility for on-chip molecular electronics operative at room temperature.
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Affiliation(s)
- Angelika Balliou
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Agia Paraskevi Attikis, Athens 15310, Greece. School of Chemical Engineering, National Technical University of Athens, Zografos Campus, 15773, Greece
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12
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Hoy EP, Mazziotti DA, Seideman T. Development and application of a 2-electron reduced density matrix approach to electron transport via molecular junctions. J Chem Phys 2018; 147:184110. [PMID: 29141419 DOI: 10.1063/1.4986804] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Can an electronic device be constructed using only a single molecule? Since this question was first asked by Aviram and Ratner in the 1970s [Chem. Phys. Lett. 29, 277 (1974)], the field of molecular electronics has exploded with significant experimental advancements in the understanding of the charge transport properties of single molecule devices. Efforts to explain the results of these experiments and identify promising new candidate molecules for molecular devices have led to the development of numerous new theoretical methods including the current standard theoretical approach for studying single molecule charge transport, i.e., the non-equilibrium Green's function formalism (NEGF). By pairing this formalism with density functional theory (DFT), a wide variety of transport problems in molecular junctions have been successfully treated. For some systems though, the conductance and current-voltage curves predicted by common DFT functionals can be several orders of magnitude above experimental results. In addition, since density functional theory relies on approximations to the exact exchange-correlation functional, the predicted transport properties can show significant variation depending on the functional chosen. As a first step to addressing this issue, the authors have replaced density functional theory in the NEGF formalism with a 2-electron reduced density matrix (2-RDM) method, creating a new approach known as the NEGF-RDM method. 2-RDM methods provide a more accurate description of electron correlation compared to density functional theory, and they have lower computational scaling compared to wavefunction based methods of similar accuracy. Additionally, 2-RDM methods are capable of capturing static electron correlation which is untreatable by existing NEGF-DFT methods. When studying dithiol alkane chains and dithiol benzene in model junctions, the authors found that the NEGF-RDM predicts conductances and currents that are 1-2 orders of magnitude below those of B3LYP and M06 DFT functionals. This suggests that the NEGF-RDM method could be a viable alternative to NEGF-DFT for molecular junction calculations.
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Affiliation(s)
- Erik P Hoy
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA
| | - David A Mazziotti
- Department of Chemistry and The James Frank Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - Tamar Seideman
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA
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13
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Lo KC, Hau KI, Chan WK. Photoconductivity enhancement and charge transport properties in ruthenium-containing block copolymer/carbon nanotube hybrids. NANOSCALE 2018; 10:6474-6486. [PMID: 29569662 DOI: 10.1039/c7nr09670d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Functional polymer/carbon nanotube (CNT) hybrid materials can serve as a good model for light harvesting systems based on CNTs. This paper presents the synthesis of block copolymer/CNT hybrids and the characterization of their photocurrent responses by both experimental and computational approaches. A series of functional diblock copolymers was synthesized by reversible addition-fragmentation chain transfer polymerizations for the dispersion and functionalization of CNTs. The block copolymers contain photosensitizing ruthenium complexes and modified pyrene-based anchoring units. The photocurrent responses of the polymer/CNT hybrids were measured by photoconductive atomic force microscopy (PCAFM), from which the experimental data were analyzed by vigorous statistical models. The difference in photocurrent response among different hybrids was correlated to the conformations of the hybrids, which were elucidated by molecular dynamics simulations, and the electronic properties of polymers. The photoresponse of the block copolymer/CNT hybrids can be enhanced by introducing an electron-accepting block between the photosensitizing block and the CNT. We have demonstrated that the application of a rigorous statistical methodology can unravel the charge transport properties of these hybrid materials and provide general guidelines for the design of molecular light harvesting systems.
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Affiliation(s)
- Kin Cheung Lo
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - King In Hau
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Wai Kin Chan
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
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14
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Dou KP, Kaun CC, Zhang RQ. Selective interface transparency in graphene nanoribbon based molecular junctions. NANOSCALE 2018; 10:4861-4864. [PMID: 29473924 DOI: 10.1039/c7nr08564h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A clear understanding of electrode-molecule interfaces is a prerequisite for the rational engineering of future generations of nanodevices that will rely on single-molecule coupling between components. With a model system, we reveal a peculiar dependence on interfaces in all graphene nanoribbon-based carbon molecular junctions. The effect can be classified into two types depending on the intrinsic feature of the embedded core graphene nanoflake (GNF). For metallic GNFs with |NA - NB| = 1, good/poor contact transparency occurs when the core device aligns with the center/edge of the electrode. The situation is reversed when a semiconducting GNF is the device, where NA = NB. These results may shed light on the design of real connecting components in graphene-based nanocircuits.
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Affiliation(s)
- K P Dou
- Department of Physics, City University of Hong Kong, Hong Kong SAR, China.
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15
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Isshiki Y, Fujii S, Nishino T, Kiguchi M. Fluctuation in Interface and Electronic Structure of Single-Molecule Junctions Investigated by Current versus Bias Voltage Characteristics. J Am Chem Soc 2018; 140:3760-3767. [DOI: 10.1021/jacs.7b13694] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuji Isshiki
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Shintaro Fujii
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Tomoaki Nishino
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Manabu Kiguchi
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
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16
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Xie Z, Bâldea I, Demissie AT, Smith CE, Wu Y, Haugstad G, Frisbie CD. Exceptionally Small Statistical Variations in the Transport Properties of Metal–Molecule–Metal Junctions Composed of 80 Oligophenylene Dithiol Molecules. J Am Chem Soc 2017; 139:5696-5699. [DOI: 10.1021/jacs.7b01918] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
| | - Ioan Bâldea
- Theoretical
Chemistry, Heidelberg University, INF 229, D-69120 Heidelberg, Germany
- Institute of Space Sciences, NILPRP, RO 077125 Bucharest-Măgurele, Romania
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17
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Tsutsui M, Yokota K, Morikawa T, Taniguchi M. Roles of vacuum tunnelling and contact mechanics in single-molecule thermopower. Sci Rep 2017; 7:44276. [PMID: 28281684 PMCID: PMC5345045 DOI: 10.1038/srep44276] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 02/06/2017] [Indexed: 11/26/2022] Open
Abstract
Molecular junction is a chemically-defined nanostructure whose discrete electronic states are expected to render enhanced thermoelectric figure of merit suitable for energy-harvesting applications. Here, we report on geometrical dependence of thermoelectricity in metal-molecule-metal structures. We performed simultaneous measurements of the electrical conductance and thermovoltage of aromatic molecules having different anchoring groups at room temperature in vacuum. We elucidated the mutual contributions of vacuum tunnelling on thermoelectricity in the short molecular bridges. We also found stretching-induced thermoelectric voltage enhancement in thiol-linked single-molecule bridges along with absence of the pulling effects in diamine counterparts, thereby suggested that the electromechanical effect would be a rather universal phenomenon in Au-S anchored molecular junctions that undergo substantial metal-molecule contact elongation upon stretching. The present results provide a novel concept for molecular design to achieve high thermopower with single-molecule junctions.
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Affiliation(s)
- Makusu Tsutsui
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Kazumichi Yokota
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Takanori Morikawa
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Masateru Taniguchi
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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18
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Partovi-Azar P, Kaghazchi P. Time-dependent density functional theory study on direction-dependent electron and hole transfer processes in molecular systems. J Comput Chem 2017; 38:698-703. [DOI: 10.1002/jcc.24730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/10/2016] [Accepted: 12/19/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Pouya Partovi-Azar
- Institute of Chemistry and Biochemistry, Physical and Theoretical Chemistry, Freie Universität Berlin; Takustr. 3 Berlin 14195 Germany
| | - Payam Kaghazchi
- Institute of Chemistry and Biochemistry, Physical and Theoretical Chemistry, Freie Universität Berlin; Takustr. 3 Berlin 14195 Germany
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19
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Zhang Q, Liu L, Tao S, Wang C, Zhao C, González C, Dappe YJ, Nichols RJ, Yang L. Graphene as a Promising Electrode for Low-Current Attenuation in Nonsymmetric Molecular Junctions. NANO LETTERS 2016; 16:6534-6540. [PMID: 27668518 DOI: 10.1021/acs.nanolett.6b03180] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We have measured the single-molecule conductance of 1,n-alkanedithiol molecular bridges (n = 4, 6, 8, 10, 12) on a graphene substrate using scanning tunneling microscopy (STM)-formed electrical junctions. The conductance values of this homologous series ranged from 2.3 nS (n = 12) to 53 nS (n = 4), with a decay constant βn of 0.40 per methylene (-CH2) group. This result is explained by a combination of density functional theory (DFT) and Keldysh-Green function calculations. The obtained decay, which is much lower than the one obtained for symmetric gold junctions, is related to the weak coupling at the molecule-graphene interface and the electronic structure of graphene. As a consequence, we show that using graphene nonsymmetric junctions and appropriate anchoring groups may lead to a much-lower decay constant and more-conductive molecular junctions at longer lengths.
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Affiliation(s)
- Qian Zhang
- Department of Chemistry, University of Liverpool , Liverpool, L69 7ZD U.K
| | - Longlong Liu
- Department of Chemistry and Chemical Engineering, Chongqing University , Chongqing, 400030, China
| | - Shuhui Tao
- Department of Chemistry, University of Liverpool , Liverpool, L69 7ZD U.K
| | | | | | - César González
- SPEC, CEA, CNRS, Université Paris-Saclay , CEA Saclay 91191 Gif-sur-Yvette Cedex, France
- Departamento de Electrónica y Tecnología de Computadores, Universidad de Granada , Campus de Fuente Nueva & CITIC, Campus de Aynadamar 18071, Granada, Spain
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay , CEA Saclay 91191 Gif-sur-Yvette Cedex, France
| | - Richard J Nichols
- Department of Chemistry, University of Liverpool , Liverpool, L69 7ZD U.K
| | - Li Yang
- Department of Chemistry, University of Liverpool , Liverpool, L69 7ZD U.K
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20
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Yamada A, Feng Q, Hoskins A, Fenk KD, Dunietz BD. Achieving Predictive Description of Molecular Conductance by Using a Range-Separated Hybrid Functional. NANO LETTERS 2016; 16:6092-6098. [PMID: 27636328 DOI: 10.1021/acs.nanolett.6b02241] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The conductance of molecular bridges tends to be overestimated by computational studies in comparison to measured values. While this well-established trend may be related to difficulties for achieving robust bridges, the employed computational scheme can also contribute to this tendency. In particular, caveats of the traditional functionals employed in first-principles-based calculations can lead to discrepancies reflected in exaggerated conductance. Here, we show that by employing a range-separated hybrid functional the calculated values are within the same order as the measured conductance for all four considered cases. On the other hand, with B3LYP, which is a widely used functional, the calculated values greatly overestimate the conductance (by about 1-2 orders of magnitude). The improved description of the conductance with a RSH functional builds on achieving a physically meaningful treatment of the quasi particles associated with the frontier orbitals.
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Affiliation(s)
- Atsushi Yamada
- Department of Chemistry and Biochemistry, Kent State University , Kent, Ohio 44242, United States
| | - Qingguo Feng
- Department of Chemistry and Biochemistry, Kent State University , Kent, Ohio 44242, United States
| | - Austin Hoskins
- Department of Chemistry and Biochemistry, Kent State University , Kent, Ohio 44242, United States
| | - Kevin D Fenk
- Department of Chemistry and Biochemistry, Kent State University , Kent, Ohio 44242, United States
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry, Kent State University , Kent, Ohio 44242, United States
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21
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Size evolution relativistic DFT-QTAIM study on the gold cluster complexes Au4-S-CnH2n-S′-Au4′ (n = 2–5). Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.08.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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22
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Kaur RP, Sawhney RS, Engles D. Effect of gold electrode crystallographic orientations on charge transport through aromatic molecular junctions. Mol Phys 2016. [DOI: 10.1080/00268976.2016.1197431] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Rupan Preet Kaur
- Department of Electronics Technology, Guru Nanak Dev University, Amritsar, India
| | | | - Derick Engles
- Department of Electronics Technology, Guru Nanak Dev University, Amritsar, India
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23
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Liu R, Wang CK, Li ZL. A method to study electronic transport properties of molecular junction: one-dimension transmission combined with three-dimension correction approximation (OTCTCA). Sci Rep 2016; 6:21946. [PMID: 26911451 PMCID: PMC4766509 DOI: 10.1038/srep21946] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 02/03/2016] [Indexed: 11/09/2022] Open
Abstract
Based on the ab initio calculation, a method of one-dimension transmission combined with three-dimension correction approximation (OTCTCA) is developed to investigate electron-transport properties of molecular junctions. The method considers that the functional molecule provides a spatial distribution of effective potential field for the electronic transport. The electrons are injected from one electrode by bias voltage, then transmit through the potential field around the functional molecule, at last are poured into the other electrode with a specific transmission probability which is calculated from one-dimension Schrödinger equation combined with three-dimension correction. The electron-transport properties of alkane diamines and 4, 4′-bipyridine molecular junctions are studied by applying OTCTCA method. The numerical results show that the conductance obviously exponentially decays with the increase of molecular length. When stretching molecular junctions, steps with a certain width are presented in conductance traces. Especially, in stretching process of 4, 4′-bipyridine molecular junction, if the terminal N atom is broken from flat part of electrode tip and exactly there is a surface Au atom on the tip nearby the N atom, the molecule generally turns to absorb on the surface Au atom, which further results in another lower conductance step in the traces as the experimental probing.
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Affiliation(s)
- Ran Liu
- School of Physics and Electronics, Shandong Normal University, Jinan, 250014, China
| | - Chuan-Kui Wang
- School of Physics and Electronics, Shandong Normal University, Jinan, 250014, China
| | - Zong-Liang Li
- School of Physics and Electronics, Shandong Normal University, Jinan, 250014, China
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24
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Fingerprinting Electronic Molecular Complexes in Liquid. Sci Rep 2016; 6:19009. [PMID: 26743542 PMCID: PMC4705545 DOI: 10.1038/srep19009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 12/02/2015] [Indexed: 01/14/2023] Open
Abstract
Predicting the electronic framework of an organic molecule under practical conditions is essential if the molecules are to be wired in a realistic circuit. This demands a clear description of the molecular energy levels and dynamics as it adapts to the feedback from its evolving chemical environment and the surface topology. Here, we address this issue by monitoring in real-time the structural stability and intrinsic molecular resonance states of fullerene (C60)-based hybrid molecules in the presence of the solvent. Energetic levels of C60 hybrids are resolved by in situ scanning tunnelling spectroscopy with an energy resolution in the order of 0.1 eV at room-temperature. An ultra-thin organic spacer layer serves to limit contact metal-molecule energy overlap. The measured molecular conductance gap spread is statistically benchmarked against first principles electronic structure calculations and used to quantify the diversity in electronic species within a standard population of molecules. These findings provide important progress towards understanding conduction mechanisms at a single-molecular level and in serving as useful guidelines for rational design of robust nanoscale devices based on functional organic molecules.
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25
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Controlling single-molecule junction conductance by molecular interactions. Sci Rep 2015; 5:11796. [PMID: 26135251 PMCID: PMC4488765 DOI: 10.1038/srep11796] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 06/05/2015] [Indexed: 11/08/2022] Open
Abstract
For the rational design of single-molecular electronic devices, it is essential to understand environmental effects on the electronic properties of a working molecule. Here we investigate the impact of molecular interactions on the single-molecule conductance by accurately positioning individual molecules on the electrode. To achieve reproducible and precise conductivity measurements, we utilize relatively weak π-bonding between a phenoxy molecule and a STM-tip to form and cleave one contact to the molecule. The anchoring to the other electrode is kept stable using a chalcogen atom with strong bonding to a Cu(110) substrate. These non-destructive measurements permit us to investigate the variation in single-molecule conductance under different but controlled environmental conditions. Combined with density functional theory calculations, we clarify the role of the electrostatic field in the environmental effect that influences the molecular level alignment.
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26
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Tsutsui M, Morikawa T, He Y, Arima A, Taniguchi M. High thermopower of mechanically stretched single-molecule junctions. Sci Rep 2015; 5:11519. [PMID: 26112999 PMCID: PMC4481826 DOI: 10.1038/srep11519] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 05/29/2015] [Indexed: 11/10/2022] Open
Abstract
Metal-molecule-metal junction is a promising candidate for thermoelectric applications that utilizes quantum confinement effects in the chemically defined zero-dimensional atomic structure to achieve enhanced dimensionless figure of merit ZT. A key issue in this new class of thermoelectric nanomaterials is to clarify the sensitivity of thermoelectricity on the molecular junction configurations. Here we report simultaneous measurements of the thermoelectric voltage and conductance on Au-1,4-benzenedithiol (BDT)-Au junctions mechanically-stretched in-situ at sub-nanoscale. We obtained the average single-molecule conductance and thermopower of 0.01 G0 and 15 μV/K, respectively, suggesting charge transport through the highest occupied molecular orbital. Meanwhile, we found the single-molecule thermoelectric transport properties extremely-sensitive to the BDT bridge configurations, whereby manifesting the importance to design the electrode-molecule contact motifs for optimizing the thermoelectric performance of molecular junctions.
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Affiliation(s)
- Makusu Tsutsui
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Takanori Morikawa
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Yuhui He
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Akihide Arima
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Masateru Taniguchi
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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27
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Adak O, Rosenthal E, Meisner J, Andrade EF, Pasupathy AN, Nuckolls C, Hybertsen MS, Venkataraman L. Flicker Noise as a Probe of Electronic Interaction at Metal-Single Molecule Interfaces. NANO LETTERS 2015; 15:4143-9. [PMID: 25942441 DOI: 10.1021/acs.nanolett.5b01270] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Charge transport properties of metal-molecule interfaces depend strongly on the character of molecule-electrode interactions. Although through-bond coupled systems have attracted the most attention, through-space coupling is important in molecular systems when, for example, through-bond coupling is suppressed due to quantum interference effects. To date, a probe that clearly distinguishes these two types of coupling has not yet been demonstrated. Here, we investigate the origin of flicker noise in single molecule junctions and demonstrate how the character of the molecule-electrode coupling influences the flicker noise behavior of single molecule junctions. Importantly, we find that flicker noise shows a power law dependence on conductance in all junctions studied with an exponent that can distinguish through-space and through-bond coupling. Our results provide a new and powerful tool for probing and understanding coupling at the metal-molecule interface.
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Affiliation(s)
| | | | | | | | | | | | - Mark S Hybertsen
- ∥Center for Functional Nanomaterials, Brookhaven National Laboratories, Upton, New York 11973, United States
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28
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Liu H, He Y, Zhang J, Zhao J, Chen L. A theoretical study of asymmetric electron transport through linearly aromatic molecules. Phys Chem Chem Phys 2015; 17:4558-68. [PMID: 25583004 DOI: 10.1039/c4cp03887h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electron transport through a series of polyacene molecules connected via a π-conjugated bridge (an anthracene molecule) was investigated theoretically by using the nonequilibrium Green's function formalism combined with density functional theory. The results have shown that the asymmetric current-voltage characteristics can be achieved by tuning the position of a side π-bridge linked to the main conjugated backbone. The detailed analyses of the spatial distribution of molecular orbitals as well as the current density interpret how the location of π-bridge strongly affects the intramolecular electronic coupling. The rectification in the molecular junction arises from the localization of the molecular orbitals near the Fermi level and the asymmetric shift of molecule orbital energy levels under positive and negative bias. The rectification ratio decreases with increasing the length of the π-bridge which improves intramolecular electronic coupling between aromatic rings. Furthermore, the rectification properties of conjugated molecules are just slightly affected by the anchoring positions of thiol groups. These results demonstrated that the location and the length of π-bridge, which induce the asymmetric intramolecular coupling, play key roles in the rectification of the linearly aromatic molecules.
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Affiliation(s)
- Hongmei Liu
- Institute of Condensed Matter Physics, Linyi University, Shuangling Road, Linyi 276000, P. R. China
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29
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Berritta M, Manrique DZ, Lambert CJ. Interplay between quantum interference and conformational fluctuations in single-molecule break junctions. NANOSCALE 2015; 7:1096-1101. [PMID: 25479372 DOI: 10.1039/c4nr05316h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We theoretically explored the combined role of conformational fluctuations and quantum interference in determining the electrical conductance of single-molecule break junctions. In particular we computed the conductance of a family of methylsulfide-functionalized trans-α,ω-diphenyloligoene molecules, with terminal phenyl rings containing meta or para linkages, for which (at least in the absence of fluctuations) destructive interference in the former is expected to decrease their electrical conductance compared with the latter. We compared the predictions of density functional theory (DFT), in which fluctuational effects are absent, with results for the conformationally-averaged conductance obtained from an ensemble of conformations obtained from classical molecular dynamics. We found that junctions formed from these molecules exhibit distinct transport regimes during junction evolution and the signatures of quantum interference in these molecules survive the effect of conformational fluctuations. Furthermore, the agreement between theory and experiment is significantly improved by including conformational averaging.
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Affiliation(s)
- Marco Berritta
- Department of Physics and Astronomy, Uppsala University, Box 516, S-75120 Uppsala, Sweden
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30
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Khoo KH, Chen Y, Li S, Quek SY. Length dependence of electron transport through molecular wires – a first principles perspective. Phys Chem Chem Phys 2015; 17:77-96. [DOI: 10.1039/c4cp05006a] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The length dependence of coherent electron transport through molecular wires is discussed in the context of a survey of state-of-the-art first principles calculation methods.
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Affiliation(s)
- Khoong Hong Khoo
- Department of Physics
- Faculty of Science
- National University of Singapore
- Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre
| | - Yifeng Chen
- Department of Physics
- Faculty of Science
- National University of Singapore
- Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre
| | - Suchun Li
- Department of Physics
- Faculty of Science
- National University of Singapore
- Singapore
- Institute of High Performance Computing
| | - Su Ying Quek
- Department of Physics
- Faculty of Science
- National University of Singapore
- Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre
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31
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Quek SY, Khoo KH. Predictive DFT-based approaches to charge and spin transport in single-molecule junctions and two-dimensional materials: successes and challenges. Acc Chem Res 2014; 47:3250-7. [PMID: 24933289 DOI: 10.1021/ar4002526] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CONSPECTUS: The emerging field of flexible electronics based on organics and two-dimensional (2D) materials relies on a fundamental understanding of charge and spin transport at the molecular and nanoscale. It is desirable to make predictions and shine light on unexplained experimental phenomena independently of experimentally derived parameters. Indeed, density functional theory (DFT), the workhorse of first-principles approaches, has been used extensively to model charge/spin transport at the nanoscale. However, DFT is essentially a ground state theory that simply guarantees correct total energies given the correct charge density, while charge/spin transport is a nonequilibrium phenomenon involving the scattering of quasiparticles. In this Account, we critically assess the validity and applicability of DFT to predict charge/spin transport at the nanoscale. We also describe a DFT-based approach, DFT+Σ, which incorporates corrections to Kohn-Sham energy levels based on many-electron calculations. We focus on single-molecule junctions and then discuss how the important considerations for DFT descriptions of transport can differ in 2D materials. We conclude that when used appropriately, DFT and DFT-based approaches can play an important role in making predictions and gaining insight into transport in these materials. Specifically, we shall focus on the low-bias quasi-equilibrium regime, which is also experimentally most relevant for single-molecule junctions. The next question is how well can the scattering of DFT Kohn-Sham particles approximate the scattering of true quasiparticles in the junction? Quasiparticles are electrons (holes) that are surrounded by a constantly changing cloud of holes (electrons), but Kohn-Sham particles have no physical significance. However, Kohn-Sham particles can often be used as a qualitative approximation to quasiparticles. The errors in standard DFT descriptions of transport arise primarily from errors in the Kohn-Sham energy levels (self-energy errors). These errors are small in the strong-coupling regime where the molecular levels are significantly broadened at the Fermi level but are large in the coherent off-resonant tunneling regime where DFT overestimates conductance by orders of magnitude. The DFT+Σ approach uses a physically motivated, parameter free estimate of the self-energy corrections to correct the energy levels in DFT, giving conductance in quantitative agreement with experiment for a large but nonexhaustive class of single-molecule junctions. In 2D materials, the self-energy error is relatively small, and critical issues stem instead from the large length scales in experiments, which make it necessary to consider band-bending within the 2D material, as well as scattering due to electron-phonon interactions, spin-flip interactions, defects, etc.
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Affiliation(s)
- Su Ying Quek
- Department of Physics, Graphene Research Centre, and Centre for Computational Science and Engineering, National University of Singapore, 2 Science Drive 3, Singapore 117551
- Institute of High
Performance Computing, Agency for Science Technology and Research, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632
| | - Khoong Hong Khoo
- Department of Physics, Graphene Research Centre, and Centre for Computational Science and Engineering, National University of Singapore, 2 Science Drive 3, Singapore 117551
- Institute of High
Performance Computing, Agency for Science Technology and Research, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632
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32
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Saraiva-Souza A, Smeu M, Zhang L, Souza Filho AG, Guo H, Ratner MA. Molecular Spintronics: Destructive Quantum Interference Controlled by a Gate. J Am Chem Soc 2014; 136:15065-71. [DOI: 10.1021/ja508537n] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Aldilene Saraiva-Souza
- Centre
for the Physics of Materials and Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada
| | - Manuel Smeu
- Departamento
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Lei Zhang
- Centre
for the Physics of Materials and Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada
| | | | - Hong Guo
- Centre
for the Physics of Materials and Department of Physics, McGill University, Montreal, QC H3A 2T8, Canada
| | - Mark A. Ratner
- Departamento
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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33
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Batra A, Kladnik G, Gorjizadeh N, Meisner J, Steigerwald M, Nuckolls C, Quek SY, Cvetko D, Morgante A, Venkataraman L. Trimethyltin-Mediated Covalent Gold–Carbon Bond Formation. J Am Chem Soc 2014; 136:12556-9. [DOI: 10.1021/ja5061406] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Gregor Kladnik
- CNR-IOM Laboratorio Nazionale TASC, I-34012 Trieste, Italy
- Department
of Physics, University of Trieste, I-34127 Trieste, Italy
| | - Narjes Gorjizadeh
- Department of Physics, National University of Singapore, 117551 Singapore
- Institute of High
Performance Computing, Agency for Science, Technology and Research−A*STAR, 138632 Singapore
| | | | | | | | - Su Ying Quek
- Department of Physics, National University of Singapore, 117551 Singapore
- Institute of High
Performance Computing, Agency for Science, Technology and Research−A*STAR, 138632 Singapore
| | - Dean Cvetko
- Department
of Physics, University of Ljubljana, SI-1000 Ljubljana, Slovenia
- CNR-IOM Laboratorio Nazionale TASC, I-34012 Trieste, Italy
| | - Alberto Morgante
- CNR-IOM Laboratorio Nazionale TASC, I-34012 Trieste, Italy
- Department
of Physics, University of Trieste, I-34127 Trieste, Italy
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34
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Quantifying thiol-gold interactions towards the efficient strength control. Nat Commun 2014; 5:4348. [PMID: 25000336 DOI: 10.1038/ncomms5348] [Citation(s) in RCA: 390] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 06/09/2014] [Indexed: 12/25/2022] Open
Abstract
The strength of the thiol-gold interactions provides the basis to fabricate robust self-assembled monolayers for diverse applications. Investigation on the stability of thiol-gold interactions has thus become a hot topic. Here we use atomic force microscopy to quantify the stability of individual thiol-gold contacts formed both by isolated single thiols and in self-assembled monolayers on gold surface. Our results show that the oxidized gold surface can enhance greatly the stability of gold-thiol contacts. In addition, the shift of binding modes from a coordinate bond to a covalent bond with the change in environmental pH and interaction time has been observed experimentally. Furthermore, isolated thiol-gold contact is found to be more stable than that in self-assembled monolayers. Our findings revealed mechanisms to control the strength of thiol-gold contacts and will help guide the design of thiol-gold contacts for a variety of practical applications.
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35
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Yan S, Long M, Zhang X, He J, Xu H, Chen K. Effects of the magnetic anchoring groups on spin-dependent transport properties of Ni(dmit)2 device. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.05.060] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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36
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Ramos-Berdullas N, Mandado M. Revisiting the Calculation of I/V Profiles in Molecular Junctions Using the Uncertainty Principle. J Phys Chem A 2014; 118:3827-3834. [PMID: 24689867 DOI: 10.1021/jp501485a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nicolás Ramos-Berdullas
- Department
of Physical Chemistry, University of Vigo, Lagoas-Marcosende s/n, 36310 Vigo, Spain
| | - Marcos Mandado
- Department
of Physical Chemistry, University of Vigo, Lagoas-Marcosende s/n, 36310 Vigo, Spain
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37
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Long XJ, Zhu J, Hao YJ, Xiang G, Liang XC, Chen LQ. Orientation effect on the electronic transport properties of C6 cluster. COMPUT THEOR CHEM 2014. [DOI: 10.1016/j.comptc.2013.12.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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38
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Huang MJ, Hsu LY, Fu MD, Chuang ST, Tien FW, Chen CH. Conductance of Tailored Molecular Segments: A Rudimentary Assessment by Landauer Formulation. J Am Chem Soc 2014; 136:1832-41. [DOI: 10.1021/ja4088538] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Min-Jie Huang
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan 10617
| | - Liang-Yan Hsu
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan 10617
| | - Ming-Dung Fu
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan 10617
| | - Su-Ting Chuang
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan 10617
| | - Fang-Wei Tien
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan 10617
| | - Chun-hsien Chen
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan 10617
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39
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Pires E, Macdonald JE, Elliott M. Chain length and temperature dependence of alkanedithiol molecular conductance under ultra high vacuum. NANOSCALE 2013; 5:9397-9403. [PMID: 23959150 DOI: 10.1039/c3nr03682k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report scanning tunnelling microscope (STM) measurements of the single molecule conductance of α,ω-alkanedithiols for a large range of molecular chain lengths (N = 3-10) and temperatures (180-390 K) under ultra high vacuum. Two STM-based measurement techniques were employed on molecules trapped between tip and substrate: (i) the well established current-distance or I(z) technique and (ii) a new I(V,z) technique in which the current-voltage characteristics are determined as the tip-substrate distance z is varied. Low, medium, and high conductance groups were observed for each molecular length, which were temperature independent over the range examined, consistent with off-resonance tunnelling. For N > 4 the current-voltage characteristics and conductance trend with chain length is well described using a simple rectangular tunnel barrier model with parameters in excellent agreement with previously reported values. However, both 1,3-propanedithiol (N = 3) and 1,4-butanedithiol (N = 4) show an anomalous behaviour which is qualitatively similar to, but much less pronounced than, that reported by Haiss et al. (Phys. Chem. Chem. Phys., 2009, 11, 10831) for measurements performed under air and nitrogen gas.
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Affiliation(s)
- Ellis Pires
- School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, UK.
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40
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Szyja BM, Nguyen HC, Kosov D, Doltsinis NL. Erratum to: Conformation-dependent conductance through a molecular break junction. J Mol Model 2013. [DOI: 10.1007/s00894-013-1973-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Hsieh SC, Mai FD, Jang S, Tang HY, Li FY. Geometric Effects on Conductance in Single Molecule Electron Transport Junctions. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200900173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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42
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Dell EJ, Capozzi B, DuBay KH, Berkelbach TC, Moreno JR, Reichman DR, Venkataraman L, Campos LM. Impact of Molecular Symmetry on Single-Molecule Conductance. J Am Chem Soc 2013; 135:11724-7. [DOI: 10.1021/ja4055367] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emma J. Dell
- Department of Chemistry, Columbia University, New York, New York 10027, United
States
| | - Brian Capozzi
- Department of Applied
Physics
and Mathematics, Columbia University, New
York, New York 10027, United States
| | - Kateri H. DuBay
- Department of Chemistry, Columbia University, New York, New York 10027, United
States
| | - Timothy C. Berkelbach
- Department of Chemistry, Columbia University, New York, New York 10027, United
States
| | - Jose Ricardo Moreno
- Department of Chemistry, Columbia University, New York, New York 10027, United
States
| | - David R. Reichman
- Department of Chemistry, Columbia University, New York, New York 10027, United
States
| | - Latha Venkataraman
- Department of Applied
Physics
and Mathematics, Columbia University, New
York, New York 10027, United States
| | - Luis M. Campos
- Department of Chemistry, Columbia University, New York, New York 10027, United
States
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43
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French WR, Iacovella CR, Rungger I, Souza AM, Sanvito S, Cummings PT. Atomistic simulations of highly conductive molecular transport junctions under realistic conditions. NANOSCALE 2013; 5:3654-3659. [PMID: 23552959 DOI: 10.1039/c3nr00459g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report state-of-the-art atomistic simulations combined with high-fidelity conductance calculations to probe structure-conductance relationships in Au-benzenedithiolate (BDT)-Au junctions under elongation. Our results demonstrate that large increases in conductance are associated with the formation of monatomic chains (MACs) of Au atoms directly connected to BDT. An analysis of the electronic structure of the simulated junctions reveals that enhancement in the s-like states in Au MACs causes the increases in conductance. Other structures also result in increased conductance but are too short-lived to be detected in experiment, while MACs remain stable for long simulation times. Examinations of thermally evolved junctions with and without MACs show negligible overlap between conductance histograms, indicating that the increase in conductance is related to this unique structural change and not thermal fluctuation. These results, which provide an excellent explanation for a recently observed anomalous experimental result [Bruot et al., Nat. Nanotechnol., 2012, 7, 35-40], should aid in the development of mechanically responsive molecular electronic devices.
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Affiliation(s)
- William R French
- Department of Chemical and Biomolecular Engineering, Nashville, TN, USA
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44
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Li B, Levy TJ, Swenson DWH, Rabani E, Miller WH. A Cartesian quasi-classical model to nonequilibrium quantum transport: The Anderson impurity model. J Chem Phys 2013; 138:104110. [DOI: 10.1063/1.4793747] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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45
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Ballesteros LM, Martín S, Cortés J, Marqués-González S, Higgins SJ, Nichols RJ, Low PJ, Cea P. Controlling the Structural and Electrical Properties of Diacid Oligo(Phenylene Ethynylene) Langmuir-Blodgett Films. Chemistry 2013; 19:5352-63. [DOI: 10.1002/chem.201203261] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 12/23/2012] [Indexed: 11/10/2022]
Affiliation(s)
- Luz Marina Ballesteros
- Departamento de Química Física, Facultad de Ciencias, Universidad de Zaragoza, Zaragoza 50009, Spain
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46
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Ramos-Berdullas N, Mandado M. Electronic Properties ofp-Xylylene andp-Phenylene Chains Subjected to Finite Bias Voltages: A New Highly Conducting Oligophenyl Structure. Chemistry 2013; 19:3646-54. [DOI: 10.1002/chem.201203324] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 11/26/2012] [Indexed: 11/09/2022]
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47
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George C, Szleifer I, Ratner M. Multiple-time-scale motion in molecularly linked nanoparticle arrays. ACS NANO 2013. [PMID: 23199199 DOI: 10.1021/nn303320w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We explore the transport of electrons between electrodes that encase a two-dimensional array of metallic quantum dots linked by molecular bridges (such as α,ω alkaline dithiols). Because the molecules can move at finite temperatures, the entire transport structure comprising the quantum dots and the molecules is in dynamical motion while the charge is being transported. There are then several physical processes (physical excursions of molecules and quantum dots, electronic migration, ordinary vibrations), all of which influence electronic transport. Each can occur on a different time scale. It is therefore not appropriate to use standard approaches to this sort of electron transfer problem. Instead, we present a treatment in which three different theoretical approaches-kinetic Monte Carlo, classical molecular dynamics, and quantum transport-are all employed. In certain limits, some of the dynamical effects are unimportant. But in general, the transport seems to follow a sort of dynamic bond percolation picture, an approach originally introduced as formal models and later applied to polymer electrolytes. Different rate-determining steps occur in different limits. This approach offers a powerful scheme for dealing with multiple time scale transport problems, as will exist in many situations with several pathways through molecular arrays or even individual molecules that are dynamically disordered.
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Affiliation(s)
- Christopher George
- Department of Chemistry, Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA
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48
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Pal PP, Dunietz BD. On the suppression and significance of ghost transmission in electron transport modeling of single molecule junctions. J Chem Phys 2012. [DOI: 10.1063/1.4767344] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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49
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Mota AJ, Álvarez de Cienfuegos L, Morcillo SP, Fuentes N, Miguel D, Rodríguez-Bolívar S, Gómez-Campos FM, Cárdenas DJ, Cuerva JM. Thermally Driven Nanofuses Based on Organometallic Rotors. Chemphyschem 2012; 13:3857-65. [DOI: 10.1002/cphc.201200544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/17/2012] [Indexed: 11/07/2022]
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50
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Xu Y, Wang BJ, Ke SH, Yang W, Alzahrani AZ. Highly tunable spin-dependent electron transport through carbon atomic chains connecting two zigzag graphene nanoribbons. J Chem Phys 2012; 137:104107. [PMID: 22979850 DOI: 10.1063/1.4752197] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Yuehua Xu
- Key Laboratory of Advanced Microstructured Materials, MOE, Department of Physics, Tongji University, 1239 Siping Road, Shanghai 200092, People's Republic of China
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