1
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Mejía L, Cossio P, Franco I. Microscopic theory, analysis, and interpretation of conductance histograms in molecular junctions. Nat Commun 2023; 14:7646. [PMID: 37996422 PMCID: PMC10667247 DOI: 10.1038/s41467-023-43169-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 11/02/2023] [Indexed: 11/25/2023] Open
Abstract
Molecular electronics break-junction experiments are widely used to investigate fundamental physics and chemistry at the nanoscale. Reproducibility in these experiments relies on measuring conductance on thousands of freshly formed molecular junctions, yielding a broad histogram of conductance events. Experiments typically focus on the most probable conductance, while the information content of the conductance histogram has remained unclear. Here we develop a microscopic theory for the conductance histogram by merging the theory of force-spectroscopy with molecular conductance. The procedure yields analytical equations that accurately fit the conductance histogram of a wide range of molecular junctions and augments the information content that can be extracted from them. Our formulation captures contributions to the conductance dispersion due to conductance changes during the mechanical elongation inherent to the experiments. In turn, the histogram shape is determined by the non-equilibrium stochastic features of junction rupture and formation. The microscopic parameters in the theory capture the junction's electromechanical properties and can be isolated from separate conductance and rupture force (or junction-lifetime) measurements. The predicted behavior can be used to test the range of validity of the theory, understand the conductance histograms, design molecular junction experiments with enhanced resolution and molecular devices with more reproducible conductance properties.
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Affiliation(s)
- Leopoldo Mejía
- Department of Chemistry, University of Rochester, Rochester, NY, 14627, USA.
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| | - Pilar Cossio
- Center for Computational Mathematics, Flatiron Institute, New York City, NY, 10010, USA
- Center for Computational Biology, Flatiron Institute, New York City, NY, 10010, USA
- Biophysics of Tropical Diseases Max Planck Tandem Group, University of Antioquia, 050010, Medellín, Colombia
| | - Ignacio Franco
- Department of Chemistry, University of Rochester, Rochester, NY, 14627, USA.
- Department of Physics, University of Rochester, Rochester, NY, 14627, USA.
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2
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Liu H, Chen L, Zhang H, Yang Z, Ye J, Zhou P, Fang C, Xu W, Shi J, Liu J, Yang Y, Hong W. Single-molecule photoelectron tunnelling spectroscopy. NATURE MATERIALS 2023; 22:1007-1012. [PMID: 37349394 DOI: 10.1038/s41563-023-01591-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 05/25/2023] [Indexed: 06/24/2023]
Abstract
Experimental mapping of transmission is essential for understanding and controlling charge transport through molecular devices and materials. Here we developed a single-molecule photoelectron tunnelling spectroscopy approach for mapping transmission beyond the HOMO-LUMO gap of the single diketopyrrolopyrrole molecule junction using an ultrafast-laser combined scanning tunnelling microscope-based break junction set-up at room temperature. Two resonant transport channels of ultrafast photocurrent are found by our photoelectron tunnelling spectroscopy, ranging from 1.31 eV to 1.77 eV, consistent with the LUMO + 1 and LUMO + 2 in the transmission spectrum obtained by density functional theory calculations. Moreover, we observed the modulation of resonant peaks by varying bias voltages, which demonstrates the ability to quantitatively characterize the effect of the electric field on frontier molecular orbitals. Our single-molecule photoelectron tunnelling spectroscopy offers an avenue that allows us to explore the nature of energy-dependent charge transport through single-molecule junctions.
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Affiliation(s)
- Haojie Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Lijue Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Hao Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Zhangqiang Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Jingyao Ye
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Ping Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Chao Fang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Wei Xu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Jia Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Junyang Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Ye Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, China.
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3
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Deffner M, Weise MP, Zhang H, Mücke M, Proppe J, Franco I, Herrmann C. Learning Conductance: Gaussian Process Regression for Molecular Electronics. J Chem Theory Comput 2023; 19:992-1002. [PMID: 36692968 DOI: 10.1021/acs.jctc.2c00648] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Experimental studies of charge transport through single molecules often rely on break junction setups, where molecular junctions are repeatedly formed and broken while measuring the conductance, leading to a statistical distribution of conductance values. Modeling this experimental situation and the resulting conductance histograms is challenging for theoretical methods, as computations need to capture structural changes in experiments, including the statistics of junction formation and rupture. This type of extensive structural sampling implies that even when evaluating conductance from computationally efficient electronic structure methods, which typically are of reduced accuracy, the evaluation of conductance histograms is too expensive to be a routine task. Highly accurate quantum transport computations are only computationally feasible for a few selected conformations and thus necessarily ignore the rich conformational space probed in experiments. To overcome these limitations, we investigate the potential of machine learning for modeling conductance histograms, in particular by Gaussian process regression. We show that by selecting specific structural parameters as features, Gaussian process regression can be used to efficiently predict the zero-bias conductance from molecular structures, reducing the computational cost of simulating conductance histograms by an order of magnitude. This enables the efficient calculation of conductance histograms even on the basis of computationally expensive first-principles approaches by effectively reducing the number of necessary charge transport calculations, paving the way toward their routine evaluation.
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Affiliation(s)
- Michael Deffner
- Institute of Inorganic and Applied Chemistry, University of Hamburg, Hamburg22761, Germany.,The Hamburg Centre for Ultrafast Imaging, Hamburg22761, Germany
| | - Marc Philipp Weise
- Institute of Inorganic and Applied Chemistry, University of Hamburg, Hamburg22761, Germany
| | - Haitao Zhang
- Institute of Inorganic and Applied Chemistry, University of Hamburg, Hamburg22761, Germany
| | - Maike Mücke
- Institute of Physical Chemistry, Georg-August University, Göttingen37077, Germany
| | - Jonny Proppe
- Institute of Physical and Theoretical Chemistry, TU Braunschweig, Braunschweig38106, Germany
| | - Ignacio Franco
- Departments of Chemistry and Physics, University of Rochester, Rochester, New York14627-0216, United States
| | - Carmen Herrmann
- Institute of Inorganic and Applied Chemistry, University of Hamburg, Hamburg22761, Germany.,The Hamburg Centre for Ultrafast Imaging, Hamburg22761, Germany
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4
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Xiao B, Dong J, Wang Z, Wang X, Sun M, Guo J, Qian G, Li Y, Chang S. Conductance modulation of metal-molecule-metal junction via extra acid addition and its mechanism investigation. Chemphyschem 2022; 23:e202100833. [PMID: 35138016 DOI: 10.1002/cphc.202100833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/29/2022] [Indexed: 11/10/2022]
Abstract
The advance of single molecular device fabrication strongly relies on the understanding of the metal-molecule-metal junction that can response to the external stimulus. A model Lewis basic molecule DBP which can react with Lewis acid and protic acid was synthesized, then the molecular conducting behavior of the original molecule and the resulted Lewis acid-base pair were researched. Allowing for their identical physical paths for charge conducting, these results indicated that adjusting the molecular electronic structure, even not directly changing the conductive molecular backbone, could also tune the charge transporting ability by nearly one order of magnitude. Furthermore, the addition of another Lewis base - Triethylamine to Lewis acid-base pair brought the electrical properties back to that of single DBP junction, which establishs a basic understanding in the design and construction of reversible and controllable molecular device based on pyridine derived molecule.
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Affiliation(s)
- Bohuai Xiao
- Wuhan University of Science and Technology, College of Material and Metallurgy, CHINA
| | - Jianqiao Dong
- Wuhan University of Science and Technology, School of Chemistry and Chemical Engineering, 947 Heping Avenue, Qingshan District, Wuhan, CHINA
| | - Zhiye Wang
- Wuhan University of Science and Technology, College of Material and Metallurgy, CHINA
| | - Xu Wang
- Wuhan University of Science and Technology, College of Material and Metallurgy, CHINA
| | - Mingjun Sun
- Wuhan University of Science and Technology, College of Material and Metallurgy, CHINA
| | - Jing Guo
- Wuhan University of Science and Technology, College of Material and Metallurgy, CHINA
| | - Gongming Qian
- Wuhan University of Science and Technology, College of Resources and Environment, CHINA
| | - Yunchuan Li
- Wuhan University of Science and Technology, College of Material and Metallurgy, 947 Heping Avenue, Qingshan District, 430081, Wuhan, CHINA
| | - Shuai Chang
- Wuhan University of Science and Technology, College of Material and Metallurgy, CHINA
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5
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Ochoa MA, Zwolak M. Optimal in situ electromechanical sensing of molecular species. J Chem Phys 2020; 152:034109. [PMID: 31968951 DOI: 10.1063/1.5132581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigate protocols for optimal molecular detection with electromechanical nanoscale sensors under ambient conditions. Our models are representative of suspended graphene nanoribbons, which due to their piezoelectric and electronic properties provide responsive and versatile sensors. In particular, we analytically account for the corrections in the electronic transmission function and signal-to-noise ratio originating in environmental perturbations, such as thermal fluctuations and solvation effects. We also investigate the role of the sampling time in the current statistics. As a result, we formulate a protocol for optimal sensing based on the modulation of the Fermi level at a fixed bias and provide approximate forms for the current, linear susceptibility, and current fluctuations. We show how the algebraic tails in the thermally broadened transmission function affect the behavior of the signal-to-noise ratio and optimal sensing. These results provide further insights into the operation of graphene deflectometers and other techniques for electromechanical sensing.
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Affiliation(s)
- Maicol A Ochoa
- Biophysics Group, Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Michael Zwolak
- Biophysics Group, Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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6
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Analytical modeling of the junction evolution in single-molecule break junctions: towards quantitative characterization of the time-dependent process. Sci China Chem 2019. [DOI: 10.1007/s11426-019-9493-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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7
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Ochoa MA, Zwolak M. Generalized Voigt broadening due to thermal fluctuations of electromechanical nanosensors and molecular electronic junctions. J Chem Phys 2019; 150:141102. [PMID: 30981273 PMCID: PMC6611703 DOI: 10.1063/1.5081140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Graphene and other 2D materials give a platform for electromechanical sensing of biomolecules in aqueous, room temperature environments. The electronic current changes in response to mechanical deflection, indicating the presence of forces due to interactions with, e.g., molecular species. We develop illustrative models of these sensors in order to give explicit, compact expressions for the current and signal-to-noise ratio. Electromechanical structures have an electron transmission function that follows a generalized Voigt profile, with thermal fluctuations giving a Gaussian smearing analogous to thermal Doppler broadening in solution/gas-phase spectroscopic applications. The Lorentzian component of the profile comes from the contact to the electrodes. After providing an accurate approximate form of this profile, we calculate the mechanical susceptibility for a representative two-level bridge and the current fluctuations for electromechanical detection. These results give the underlying mechanics of electromechanical sensing in more complex scenarios, such as graphene deflectometry.
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Affiliation(s)
- Maicol A. Ochoa
- Biophysics Group, Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899
- Maryland Nanocenter, University of Maryland, College Park, MD 20742
| | - Michael Zwolak
- Biophysics Group, Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899
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8
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Liu J, Zhao X, Zheng J, Huang X, Tang Y, Wang F, Li R, Pi J, Huang C, Wang L, Yang Y, Shi J, Mao BW, Tian ZQ, Bryce MR, Hong W. Transition from Tunneling Leakage Current to Molecular Tunneling in Single-Molecule Junctions. Chem 2019. [DOI: 10.1016/j.chempr.2018.11.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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9
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The effect of nitrogen lone-pair interaction on the conduction in a single-molecule junction with amine-Au bonding. Sci Rep 2018; 8:5222. [PMID: 29588454 PMCID: PMC5869721 DOI: 10.1038/s41598-018-22893-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 03/01/2018] [Indexed: 11/18/2022] Open
Abstract
We have applied our previously developed three-dimensional dynamic probe method to analyze the conductance in a Au-/1,4-benzenediamine (BDA)/Au single molecule junction. This structure is a typically used example to demonstrate the high performance of the break junction (BJ) method for measuring conductance with small variations, however, details of the interaction of the nitrogen (N) lone-pair in the amine group with a Au electrode, which is considered to have a fundamental role in determining the conductance of the single molecule junction with the amine, have not yet been clarified and still remain an important issue to be resolved. In this study, we have succeeded, for the first time, in observing the site-dependent change in conductance of this system while the molecular conformation was accurately controlled, and the results were well reproduced by a simulation taking account of the effect of the N lone-pair in an amine bonding with a Au electrode.
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10
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Albrecht T, Slabaugh G, Alonso E, Al-Arif SMMR. Deep learning for single-molecule science. NANOTECHNOLOGY 2017; 28:423001. [PMID: 28762339 DOI: 10.1088/1361-6528/aa8334] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Exploring and making predictions based on single-molecule data can be challenging, not only due to the sheer size of the datasets, but also because a priori knowledge about the signal characteristics is typically limited and poor signal-to-noise ratio. For example, hypothesis-driven data exploration, informed by an expectation of the signal characteristics, can lead to interpretation bias or loss of information. Equally, even when the different data categories are known, e.g., the four bases in DNA sequencing, it is often difficult to know how to make best use of the available information content. The latest developments in machine learning (ML), so-called deep learning (DL) offer interesting, new avenues to address such challenges. In some applications, such as speech and image recognition, DL has been able to outperform conventional ML strategies and even human performance. However, to date DL has not been applied much in single-molecule science, presumably in part because relatively little is known about the 'internal workings' of such DL tools within single-molecule science as a field. In this Tutorial, we make an attempt to illustrate in a step-by-step guide how one of those, a convolutional neural network (CNN), may be used for base calling in DNA sequencing applications. We compare it with a SVM as a more conventional ML method, and discuss some of the strengths and weaknesses of the approach. In particular, a 'deep' neural network has many features of a 'black box', which has important implications on how we look at and interpret data.
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Affiliation(s)
- Tim Albrecht
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom
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11
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Liu J, Zhao X, Al-Galiby Q, Huang X, Zheng J, Li R, Huang C, Yang Y, Shi J, Manrique DZ, Lambert CJ, Bryce MR, Hong W. Radical-Enhanced Charge Transport in Single-Molecule Phenothiazine Electrical Junctions. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201707710] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Junyang Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Xiaotao Zhao
- Department of Chemistry; Durham University; Durham DH1 3LE UK
| | - Qusiy Al-Galiby
- Department of Physics; Lancaster University; Lancaster LA1 4YB UK
- Department of Physics; College of Education; University of Al-Qadisiyah, Al-Qadisiyah; Diwaniya city 58002 Iraq
| | - Xiaoyan Huang
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Jueting Zheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Ruihao Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Cancan Huang
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Yang Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Jia Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - David Zsolt Manrique
- Department of Physics; Lancaster University; Lancaster LA1 4YB UK
- Department of Electronic & Electrical Engineering; University College London; Torrington Place London WC1E 7JE UK
| | - Colin J. Lambert
- Department of Physics; Lancaster University; Lancaster LA1 4YB UK
| | - Martin R. Bryce
- Department of Chemistry; Durham University; Durham DH1 3LE UK
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
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12
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Liu J, Zhao X, Al-Galiby Q, Huang X, Zheng J, Li R, Huang C, Yang Y, Shi J, Manrique DZ, Lambert CJ, Bryce MR, Hong W. Radical-Enhanced Charge Transport in Single-Molecule Phenothiazine Electrical Junctions. Angew Chem Int Ed Engl 2017; 56:13061-13065. [DOI: 10.1002/anie.201707710] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Junyang Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Xiaotao Zhao
- Department of Chemistry; Durham University; Durham DH1 3LE UK
| | - Qusiy Al-Galiby
- Department of Physics; Lancaster University; Lancaster LA1 4YB UK
- Department of Physics; College of Education; University of Al-Qadisiyah, Al-Qadisiyah; Diwaniya city 58002 Iraq
| | - Xiaoyan Huang
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Jueting Zheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Ruihao Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Cancan Huang
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3 3012 Bern Switzerland
| | - Yang Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - Jia Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
| | - David Zsolt Manrique
- Department of Physics; Lancaster University; Lancaster LA1 4YB UK
- Department of Electronic & Electrical Engineering; University College London; Torrington Place London WC1E 7JE UK
| | - Colin J. Lambert
- Department of Physics; Lancaster University; Lancaster LA1 4YB UK
| | - Martin R. Bryce
- Department of Chemistry; Durham University; Durham DH1 3LE UK
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces; Department of Chemical and Biochemical Engineering; College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, iChEM; Xiamen University; Xiamen 361005 China
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13
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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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14
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Abstract
Extensive evidence has shown that long-range charge transport can occur along double helical DNA, but active control (switching) of single-DNA conductance with an external field has not yet been demonstrated. Here we demonstrate conductance switching in DNA by replacing a DNA base with a redox group. By applying an electrochemical (EC) gate voltage to the molecule, we switch the redox group between the oxidized and reduced states, leading to reversible switching of the DNA conductance between two discrete levels. We further show that monitoring the individual conductance switching allows the study of redox reaction kinetics and thermodynamics at single molecular level using DNA as a probe. Our theoretical calculations suggest that the switch is due to the change in the energy level alignment of the redox states relative to the Fermi level of the electrodes. Thanks to its base stacking structure, DNA can behave as an electric wire, but external control of its electronic properties has not been achieved yet. Here, the authors show that DNA conductance can be switched electrochemically when a DNA base is replaced by the redox molecule anthraquinone.
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15
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Tschudi SE, Reuter MG. Estimating the Landauer-Büttiker transmission function from single molecule break junction experiments. NANOTECHNOLOGY 2016; 27:425203. [PMID: 27623441 DOI: 10.1088/0957-4484/27/42/425203] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
When investigating the electronic response properties of molecules, experiments often measure conductance whereas computation predicts the transmission probability. Although Landauer-Büttiker theory usually relates the two, comparison between experiment and computation remains difficult because experimental data (specifically those from break junctions) are statistical and computational results are deterministic. In this work we develop tools to quantitatively estimate-with error bars-the shape of the Landauer-Büttiker transmission function directly from experimental statistics on conductance and thermopower (if the latter is also available). We subsequently apply these tools to existing data, demonstrating a rigorous statistical comparison between experimental and computational results on molecular electron transport.
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Affiliation(s)
- Stephen E Tschudi
- Department of Applied Mathematics & Statistics and Institute for Advanced Computational Science, Stony Brook University, Stony Brook, NY 11794, USA
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16
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Lemmer M, Inkpen MS, Kornysheva K, Long NJ, Albrecht T. Unsupervised vector-based classification of single-molecule charge transport data. Nat Commun 2016; 7:12922. [PMID: 27694904 PMCID: PMC5063956 DOI: 10.1038/ncomms12922] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/16/2016] [Indexed: 01/04/2023] Open
Abstract
The stochastic nature of single-molecule charge transport measurements requires collection of large data sets to capture the full complexity of a molecular system. Data analysis is then guided by certain expectations, for example, a plateau feature in the tunnelling current distance trace, and the molecular conductance extracted from suitable histogram analysis. However, differences in molecular conformation or electrode contact geometry, the number of molecules in the junction or dynamic effects may lead to very different molecular signatures. Since their manifestation is a priori unknown, an unsupervised classification algorithm, making no prior assumptions regarding the data is clearly desirable. Here we present such an approach based on multivariate pattern analysis and apply it to simulated and experimental single-molecule charge transport data. We demonstrate how different event shapes are clearly separated using this algorithm and how statistics about different event classes can be extracted, when conventional methods of analysis fail.
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Affiliation(s)
- Mario Lemmer
- Department of Chemistry, Imperial College London, Imperial College Road, London SW7 2AZ, UK
| | - Michael S. Inkpen
- Department of Chemistry, Imperial College London, Imperial College Road, London SW7 2AZ, UK
| | - Katja Kornysheva
- Institute for Cognitive Neuroscience, University College London, Alexandra House, 17-19 Queen Square, London WC1N 3AR, UK
| | - Nicholas J. Long
- Department of Chemistry, Imperial College London, Imperial College Road, London SW7 2AZ, UK
| | - Tim Albrecht
- Department of Chemistry, Imperial College London, Imperial College Road, London SW7 2AZ, UK
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17
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Xiang L, Hines T, Palma JL, Lu X, Mujica V, Ratner MA, Zhou G, Tao N. Non-exponential Length Dependence of Conductance in Iodide-Terminated Oligothiophene Single-Molecule Tunneling Junctions. J Am Chem Soc 2016; 138:679-87. [DOI: 10.1021/jacs.5b11605] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Limin Xiang
- Center
for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
- School
of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Thomas Hines
- Center
for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
| | - Julio L. Palma
- Center
for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
- School
of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Xuefeng Lu
- Laboratory
of Advanced Materials, Fudan University, Shanghai 200438, P.R. China
| | - Vladimiro Mujica
- School
of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Mark A. Ratner
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Gang Zhou
- Laboratory
of Advanced Materials, Fudan University, Shanghai 200438, P.R. China
| | - Nongjian Tao
- Center
for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
- School
of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287, United States
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