scholarly journals Carbon tips for all-carbon single-molecule electronics

Nanoscale ◽  
2014 ◽  
Vol 6 (12) ◽  
pp. 6953-6958 ◽  
Author(s):  
Y. J. Dappe ◽  
C. González ◽  
J. C. Cuevas
Keyword(s):  
Ab Initio ◽  
Molecular Electronics ◽  
Single Molecule ◽  
Carbon Nanostructures ◽  
Molecular Junctions ◽  
Single Molecule Electronics ◽  
Single Molecule Junctions ◽  
Carbon Based

We present anab initiostudy of the use of carbon-based tips as electrodes in single-molecule junctions. We show that carbon tips can be combined with other carbon nanostructures to form all-carbon molecular junctions with molecules like benzene or C60. Results show that the use of carbon tips can lead to conductive molecular junctions and open new perspectives in all-carbon molecular electronics.

scholarly journals Understanding resonant charge transport through weakly coupled single-molecule junctions

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
James O. Thomas ◽  
Bart Limburg ◽  
Jakub K. Sowa ◽  
Kyle Willick ◽  
Jonathan Baugh ◽  
...  
Keyword(s):  
Charge Transport ◽  
Single Molecule ◽  
Local Environment ◽  
Single Mode ◽  
Molecular Junctions ◽  
Vibrational Coupling ◽  
Weakly Coupled ◽  
Single Molecule Electronics ◽  
Single Molecule Junctions ◽  
Quantitative Understanding

Abstract Off-resonant charge transport through molecular junctions has been extensively studied since the advent of single-molecule electronics and is now well understood within the framework of the non-interacting Landauer approach. Conversely, gaining a qualitative and quantitative understanding of the resonant transport regime has proven more elusive. Here, we study resonant charge transport through graphene-based zinc-porphyrin junctions. We experimentally demonstrate an inadequacy of non-interacting Landauer theory as well as the conventional single-mode Franck–Condon model. Instead, we model overall charge transport as a sequence of non-adiabatic electron transfers, with rates depending on both outer and inner-sphere vibrational interactions. We show that the transport properties of our molecular junctions are determined by a combination of electron–electron and electron-vibrational coupling, and are sensitive to interactions with the wider local environment. Furthermore, we assess the importance of nuclear tunnelling and examine the suitability of semi-classical Marcus theory as a description of charge transport in molecular devices.

Conductivity of carbon-based molecular junctions from ab-initio methods

2014 ◽  
Vol 9 (6) ◽  
pp. 748-759 ◽  
Author(s):  
Xiao-Fei Li ◽  
Yi Luo
Keyword(s):  
Ab Initio ◽  
Molecular Junctions ◽  
Ab Initio Methods ◽  
Carbon Based

Break junction under electrochemical gating: testbed for single-molecule electronics

2015 ◽  
Vol 44 (4) ◽  
pp. 889-901 ◽  
Author(s):  
Cancan Huang ◽  
Alexander V. Rudnev ◽  
Wenjing Hong ◽  
Thomas Wandlowski
Keyword(s):  
Single Molecule ◽  
Break Junction ◽  
Single Molecule Electronics ◽  
Single Molecule Junctions ◽  
Recent Developments ◽  
Electrochemical Gating

This tutorial review highlights recent developments using break junction techniques, and emphasizes the concept of “electrochemical gating” on single-molecule junctions.

scholarly journals Enhanced coupling through π-stacking in imidazole-based molecular junctions

2019 ◽  
Vol 10 (43) ◽  
pp. 9998-10002 ◽  
Author(s):  
Tianren Fu ◽  
Shanelle Smith ◽  
María Camarasa-Gómez ◽  
Xiaofang Yu ◽  
Jiayi Xue ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Single Molecule ◽  
Scanning Tunneling Microscope ◽  
Density Functional ◽  
Molecular Junctions ◽  
Scanning Tunneling ◽  
Break Junction ◽  
Functional Theory ◽  
Tunneling Microscope ◽  
Single Molecule Junctions

We demonstrate that imidazole based π–π stacked dimers form strong and efficient conductance pathways in single-molecule junctions using the scanning-tunneling microscope-break junction (STM-BJ) technique and density functional theory-based calculations.

scholarly journals Exploring antiaromaticity in single-molecule junctions formed from biphenylene derivatives

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20659-20666
Author(s):  
Markus Gantenbein ◽  
Xiaohui Li ◽  
Sara Sangtarash ◽  
Jie Bai ◽  
Gunnar Olsen ◽  
...  
Keyword(s):  
Charge Transport ◽  
Single Molecule ◽  
Molecular Junctions ◽  
Single Molecule Junctions

We report the synthesis of a series of oligophenylene-ethynylene (OPE) derivatives with biphenylene core units, designed to assess the effects of biphenylene antiaromaticity on charge transport in molecular junctions.

scholarly journals Charge transfer through single molecule contacts: How reliable are rate descriptions?

2011 ◽  
Vol 2 ◽  
pp. 416-426 ◽  
Author(s):  
Denis Kast ◽  
L Kecke ◽  
J Ankerhold
Keyword(s):  
Charge Transfer ◽  
Exact Solutions ◽  
Ab Initio ◽  
Molecular Electronics ◽  
Single Molecule ◽  
Building Blocks ◽  
Transport Processes ◽  
Intramolecular Electron Transfer ◽  
Transfer Rates ◽  
The Impact

Background: The trend for the fabrication of electrical circuits with nanoscale dimensions has led to impressive progress in the field of molecular electronics in the last decade. However, a theoretical description of molecular contacts as the building blocks of future devices is challenging, as it has to combine the properties of Fermi liquids in the leads with charge and phonon degrees of freedom on the molecule. Outside of ab initio schemes for specific set-ups, generic models reveal the characteristics of transport processes. Particularly appealing are descriptions based on transfer rates successfully used in other contexts such as mesoscopic physics and intramolecular electron transfer. However, a detailed analysis of this scheme in comparison with numerically exact solutions is still elusive. Results: We show that a formulation in terms of transfer rates provides a quantitatively accurate description even in domains of parameter space where strictly it is expected to fail, e.g., at lower temperatures. Typically, intramolecular phonons are distributed according to a voltage driven steady state that can only roughly be captured by a thermal distribution with an effective elevated temperature (heating). An extension of a master equation for the charge–phonon complex, to effectively include the impact of off-diagonal elements of the reduced density matrix, provides very accurate solutions even for stronger electron–phonon coupling. Conclusion: Rate descriptions and master equations offer a versatile model to describe and understand charge transfer processes through molecular junctions. Such methods are computationally orders of magnitude less expensive than elaborate numerical simulations that, however, provide exact solutions as benchmarks. Adjustable parameters obtained, e.g., from ab initio calculations allow for the treatment of various realizations. Even though not as rigorously formulated as, e.g., nonequilibrium Green’s function methods, they are conceptually simpler, more flexible for extensions, and from a practical point of view provide accurate results as long as strong quantum correlations do not modify the properties of the relevant subunits substantially.

scholarly journals Molecular Electronics: Light-Induced Switching of Tunable Single-Molecule Junctions (Adv. Sci. 5/2015)

2015 ◽  
Vol 2 (5) ◽  
Author(s):  
Torsten Sendler ◽  
Katharina Luka-Guth ◽  
Matthias Wieser ◽  
Lokamani ◽  
Jannic Wolf ◽  
...  
Keyword(s):  
Molecular Electronics ◽  
Single Molecule ◽  
Single Molecule Junctions

scholarly journals Role of solvents in the electronic transport properties of single-molecule junctions

2016 ◽  
Vol 7 ◽  
pp. 1055-1067 ◽  
Author(s):  
Katharina Luka-Guth ◽  
Sebastian Hambsch ◽  
Andreas Bloch ◽  
Philipp Ehrenreich ◽  
Bernd Michael Briechle ◽  
...  
Keyword(s):  
Molecular Electronics ◽  
Single Molecule ◽  
Current Voltage ◽  
Tunnel Barriers ◽  
Single Molecule Junctions ◽  
Level Model ◽  
Current Voltage Characteristics ◽  
Solvent Molecules ◽  
Narrow Gaps

We report on an experimental study of the charge transport through tunnel gaps formed by adjustable gold electrodes immersed into different solvents that are commonly used in the field of molecular electronics (ethanol, toluene, mesitylene, 1,2,4-trichlorobenzene, isopropanol, toluene/tetrahydrofuran mixtures) for the study of single-molecule contacts of functional molecules. We present measurements of the conductance as a function of gap width, conductance histograms as well as current–voltage characteristics of narrow gaps and discuss them in terms of the Simmons model, which is the standard model for describing transport via tunnel barriers, and the resonant single-level model, often applied to single-molecule junctions. One of our conclusions is that stable junctions may form from solvents as well and that both conductance–distance traces and current–voltage characteristics have to be studied to distinguish between contacts of solvent molecules and of molecules under study.

Single-molecule junctions for molecular electronics

2016 ◽  
Vol 4 (38) ◽  
pp. 8842-8858 ◽  
Author(s):  
Yuki Komoto ◽  
Shintaro Fujii ◽  
Madoka Iwane ◽  
Manabu Kiguchi
Keyword(s):  
Molecular Electronics ◽  
Single Molecule ◽  
Unique Structure ◽  
Nano Material ◽  
Single Molecule Junctions ◽  
Molecule Junction ◽  
Single Molecule Junction ◽  
Low Dimensional

A single-molecule junction shows novel functionalities caused by its unique structure of a low-dimensional nano-material with two metal–molecule interfaces.

scholarly journals Redox-addressable single-molecule junctions incorporating a persistent organic radical

2021 ◽  
Author(s):  
Saman Naghibi ◽  
Sara Sangtarash ◽  
Varshini J. Kumar ◽  
Jian-Zhong Wu ◽  
Martyna M. Judd ◽  
...  
Keyword(s):  
Molecular Electronics ◽  
Single Molecule ◽  
Closed Shell ◽  
Open Shell ◽  
Organic Radical ◽  
Molecular Junction ◽  
Ambient Conditions ◽  
Scanning Tunnelling Microscope ◽  
Ambient Temperatures ◽  
Single Molecule Junctions

The integration of radical (open-shell) species into single-molecule junctions at non-cryogenic temperatures is a key to unlocking the potential of molecular electronics in further applications. While many efforts have been devoted to this issue, in the absence of a chemical or electrochemical potential the open-shell character is lost when in contact with the metallic electrodes. Here, the organic 6-oxo-verdazyl radical, which is stable at ambient temperatures and atmosphere, has been functionalised by aurophilic 4-thioanisole groups at the 1,5-positions and fabricated into a molecular junction using the scanning tunnelling microscope break-junction technique. The verdazyl moiety retains open-shell character within the junction even at room temperature, and electrochemical gating permits in-situ reduction of the verdazyl to the closed-shell anionic state in a single-molecule transistor configuration. In addition, the bias-dependent alignment of the open-shell resonances with respect to the electrode Fermi levels gives rise to purely electronically-driven rectifying behaviour. The demonstration of a verdazyl-based molecular junction capable of integrating radical character, transistor-like switching behaviour, and rectification in a single molecular component under ambient conditions paves the way for further studies of the electronic, magnetic, and thermoelectric properties of open-shell species.

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