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Sergeyev D, Ashikov N, Zhanturina N. Electric Transport Properties of a Model Nanojunction “Graphene–Fullerene C60–Graphene”. INTERNATIONAL JOURNAL OF NANOSCIENCE 2020. [DOI: 10.1142/s0219581x21500071] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In the framework of the density functional theory and method of nonequilibrium Green functions (DFT [Formula: see text] NEGF), the electric transport properties of the model nanojunction “Graphene–Fullerene C[Formula: see text]–Graphene” were studied. The transmission spectra, the density of states, the current–voltage characteristic (CVC) and the differential conductivity of the nanojunction are determined. The appearance of a feature of the DOS nanotransition is revealed. This is due to the fact that the Lowest Unoccupied Molecular Orbital (LUMO) of C[Formula: see text] becomes closer to the Fermi level of metal substrates than its Highest Occupied Molecular Orbital (HOMO). It is shown that Coulomb stairs associated with the Coulomb blockade effect appear on the CVC of the nanotransition. The same changes are observed on the differential conductivity spectrum in the form of eight distinct peak structures arising with period [Formula: see text][Formula: see text]V. The comparison of the electric transport characteristics of single-fullerene nanodevices with various electrode materials (graphene, gold, platinum) are presented. It was found that the voltage period of Coulomb features [Formula: see text] in a nanodevice with graphene electrodes is less than in nanodevices with platinum and gold electrodes. It was revealed that the considered nanotransition has negative differential conductivity. The results obtained can be useful in calculating promising elements of single-electronics.
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Affiliation(s)
- D. Sergeyev
- Department of Physics, K. Zhubanov Aktobe Regional State University, 34 Moldagulova avenue, 030000 Aktobe, Kazakhstan
- Department of Radio Electronics, T. Begeldinov Aktobe Avation Institute, 39 Moldagulova avenue, 030012 Aktobe, Kazakhstan
| | - N. Ashikov
- Department of Radio Electronics, T. Begeldinov Aktobe Avation Institute, 39 Moldagulova avenue, 030012 Aktobe, Kazakhstan
| | - N. Zhanturina
- Department of Physics, K. Zhubanov Aktobe Regional State University, 34 Moldagulova avenue, 030000 Aktobe, Kazakhstan
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Kuperman M, Peskin U. Field-induced inversion of resonant tunneling currents through single molecule junctions and the directional photo-electric effect. J Chem Phys 2017. [DOI: 10.1063/1.4973891] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Maayan Kuperman
- Schulich Faculty of Chemistry, Technion—Israel Institute of Technology, Haifa 32000, Israel
| | - Uri Peskin
- Schulich Faculty of Chemistry, Technion—Israel Institute of Technology, Haifa 32000, Israel
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Li Y, Zolotavin P, Doak P, Kronik L, Neaton JB, Natelson D. Interplay of Bias-Driven Charging and the Vibrational Stark Effect in Molecular Junctions. NANO LETTERS 2016; 16:1104-1109. [PMID: 26814562 DOI: 10.1021/acs.nanolett.5b04340] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We observe large, reversible, bias driven changes in the vibrational energies of PCBM based on simultaneous transport and surface-enhanced Raman spectroscopy (SERS) measurements on PCBM-gold junctions. A combination of linear and quadratic shifts in vibrational energies with voltage is analyzed and compared with similar measurements involving C60-gold junctions. A theoretical model based on density functional theory (DFT) calculations suggests that both a vibrational Stark effect and bias-induced charging of the junction contribute to the shifts in vibrational energies. In the PCBM case, a linear vibrational Stark effect is observed due to the permanent electric dipole moment of PCBM. The vibrational Stark shifts shown here for PCBM junctions are comparable to or larger than the charging effects that dominate in C60 junctions.
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Affiliation(s)
- Yajing Li
- Department of Physics and Astronomy, MS 61, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Pavlo Zolotavin
- Department of Physics and Astronomy, MS 61, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Peter Doak
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831-6493, United States
| | - Leeor Kronik
- Department of Materials and Interfaces, Weizmann Institute of Science , Rehovoth 76100, Israel
| | - Jeffrey B Neaton
- Molecular Foundry, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
- Department of Physics, University of California at Berkeley , Berkeley, California 94720, United States
- Kavli Energy Nanosciences Institute at Berkeley , Berkeley, California 94720, United States
| | - Douglas Natelson
- Department of Physics and Astronomy, MS 61, Rice University , 6100 Main Street, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, MS 366, Rice University , Houston, Texas 77005, United States
- Department of Materials Science and Nanoengineering, MS 325, Rice University , Houston, Texas 77005, United States
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Dasari R, Zamborini FP. Surface Enhanced Raman Spectroscopy at Electrochemically Fabricated Silver Nanowire Junctions. Anal Chem 2015; 88:675-81. [DOI: 10.1021/acs.analchem.5b02343] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Radhika Dasari
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
| | - Francis P. Zamborini
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
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Natelson D, Li Y, Herzog JB. Nanogap structures: combining enhanced Raman spectroscopy and electronic transport. Phys Chem Chem Phys 2013; 15:5262-75. [PMID: 23385304 DOI: 10.1039/c3cp44142c] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Surface-enhanced Raman spectroscopy (SERS) is an experimental tool for accessing vibrational and chemical information, down to the single molecule level. SERS typically relies on plasmon excitations in metal nanostructures to concentrate the incident radiation and to provide an enhanced photon density of states to couple emitted radiation to the far field. Many common SERS platforms involve metal nanoparticles to generate the required electromagnetic enhancements. Here we concentrate on an alternative approach, in which the relevant plasmon excitations are supported at a truly nanoscale gap between extended electrodes, rather than discrete subwavelength nanoparticles. The ability to fabricate precise gaps on demand, and in some cases to tune the gap size in situ, combined with the additional capability of simultaneous electronic transport measurements of the nanogap, provides access to information not previously available in standard SERS. We summarize the rich plasmonic physics at work in these extended systems and highlight the recent state of the art including tip-enhanced Raman spectroscopy (TERS) and the application of mechanical break junctions and electromigrated junctions. We describe in detail how we have performed in situ gap-enhanced Raman measurements of molecular-scale junctions while simultaneously subjecting these structures to electronic transport. These extended electrode structures allow us to study the pumping of vibrational modes by the flow of tunneling electrons, as well as the shifting of vibrational energies due to the applied bias. These experiments extend SERS into a tool for examining fundamental processes of dissipation, and provide insight into the mechanisms behind SERS spectral diffusion. We conclude with a brief discussion of future directions.
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Affiliation(s)
- Douglas Natelson
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA.
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Affiliation(s)
- Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064;
| | - Zhenhuan Zhao
- State Key Laboratory of Crystal Materials, Center of Bio and Micro/Nano Functional Materials, Shandong University, Jinan, Shandong 250100, China;
| | - Hong Liu
- State Key Laboratory of Crystal Materials, Center of Bio and Micro/Nano Functional Materials, Shandong University, Jinan, Shandong 250100, China;
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100085, China
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Song H, Reed MA, Lee T. Single molecule electronic devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2011; 23:1583-1608. [PMID: 21290434 DOI: 10.1002/adma.201004291] [Citation(s) in RCA: 256] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Indexed: 05/30/2023]
Abstract
Single molecule electronic devices in which individual molecules are utilized as active electronic components constitute a promising approach for the ultimate miniaturization and integration of electronic devices in nanotechnology through the bottom-up strategy. Thus, the ability to understand, control, and exploit charge transport at the level of single molecules has become a long-standing desire of scientists and engineers from different disciplines for various potential device applications. Indeed, a study on charge transport through single molecules attached to metallic electrodes is a very challenging task, but rapid advances have been made in recent years. This review article focuses on experimental aspects of electronic devices made with single molecules, with a primary focus on the characterization and manipulation of charge transport in this regime.
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Affiliation(s)
- Hyunwook Song
- Department of Materials Science and Engineering, Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
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Phillips H, Prociuk A, Dunietz BD. Bias effects on the electronic spectrum of a molecular bridge. J Chem Phys 2011; 134:054708. [DOI: 10.1063/1.3531695] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Ward DR, Corley DA, Tour JM, Natelson D. Vibrational and electronic heating in nanoscale junctions. NATURE NANOTECHNOLOGY 2011; 6:33-8. [PMID: 21151112 DOI: 10.1038/nnano.2010.240] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Accepted: 11/08/2010] [Indexed: 05/22/2023]
Abstract
Understanding and controlling the flow of heat is a major challenge in nanoelectronics. When a junction is driven out of equilibrium by light or the flow of electric charge, the vibrational and electronic degrees of freedom are, in general, no longer described by a single temperature. Moreover, characterizing the steady-state vibrational and electronic distributions in situ is extremely challenging. Here, we show that surface-enhanced Raman emission may be used to determine the effective temperatures for both the vibrational modes and the electrons in the current in a biased metallic nanoscale junction decorated with molecules. Molecular vibrations show mode-specific pumping by both optical excitation and d.c. current, with effective temperatures exceeding several hundred kelvin. Anti-Stokes electronic Raman emission indicates that the effective electronic temperature at bias voltages of a few hundred millivolts can reach values up to three times the values measured when there is no current. The precise effective temperatures are model-dependent, but the trends as a function of bias conditions are robust, and allow direct comparisons with theories of nanoscale heating.
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Affiliation(s)
- Daniel R Ward
- Department of Physics and Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, USA
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Wang L, May V. Laser pulse induced transient currents through a single molecule. Phys Chem Chem Phys 2011; 13:8755-68. [DOI: 10.1039/c0cp02399j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Kizuka T, Kodama S, Matsuda T. Verification of unzipping models of electromigration in gold nanocontacts by in situ high-resolution transmission electron microscopy. NANOTECHNOLOGY 2010; 21:495706. [PMID: 21079293 DOI: 10.1088/0957-4484/21/49/495706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We observed in situ the electromigration process of gold (Au) nanocontacts (NCs) by high-resolution transmission electron microscopy. The structural dynamics of the interior and surfaces of the NCs were investigated at the atomic level. In particular, we directly verified the evidence of the unzipping model of electromigration with the in situ observation of surface-edge movement. The fundamental parameters of NCs, i.e., conductance and tensile force, were also measured during in situ lattice imaging of electromigration. Atoms migrating from the negative electrode accumulated at the most constricted regions of the NCs, leading to expansion. As a result, the NCs were compressed by the two electrodes. We demonstrated the magnitude of the force acting on the NCs during electromigration. The critical voltage of electromigration was approximately 80 mV, and the current density at the critical voltage was 60 TA m(-2). We found that Au nanogaps could be fabricated by applying this bias voltage to Au NCs.
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Affiliation(s)
- Tokushi Kizuka
- Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki, Japan.
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Ward DR, Hüser F, Pauly F, Cuevas JC, Natelson D. Optical rectification and field enhancement in a plasmonic nanogap. NATURE NANOTECHNOLOGY 2010; 5:732-736. [PMID: 20852641 DOI: 10.1038/nnano.2010.176] [Citation(s) in RCA: 171] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Accepted: 07/27/2010] [Indexed: 05/29/2023]
Abstract
Metal nanostructures act as powerful optical antennas because collective modes of the electron fluid in the metal are excited when light strikes the surface of the nanostructure. These excitations, known as plasmons, can have evanescent electromagnetic fields that are orders of magnitude larger than the incident electromagnetic field. The largest field enhancements often occur in nanogaps between plasmonically active nanostructures, but it is extremely challenging to measure the fields in such gaps directly. These enhanced fields have applications in surface-enhanced spectroscopies, nonlinear optics and nanophotonics. Here we show that nonlinear tunnelling conduction between gold electrodes separated by a subnanometre gap leads to optical rectification, producing a d.c. photocurrent when the gap is illuminated. Comparing this photocurrent with low-frequency conduction measurements, we determine the optical frequency voltage across the tunnelling region of the nanogap, and also the enhancement of the electric field in the tunnelling region, as a function of gap size. The measured field enhancements exceed 1,000, consistent with estimates from surface-enhanced Raman measurements. Our results highlight the need for more realistic theoretical approaches that are able to model the electromagnetic response of metal nanostructures on scales ranging from the free-space wavelength, λ, down to ∼λ/1,000, and for experiments with new materials, different wavelengths and different incident polarizations.
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Affiliation(s)
- Daniel R Ward
- Department of Physics and Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, USA
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Carstens C, Elbracht R, Gärtner C, Becker H. Opportunities and limits of cell-based assay miniaturization in drug discovery. Expert Opin Drug Discov 2010; 5:673-9. [DOI: 10.1517/17460441.2010.488264] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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