1
|
Wang K, Vezzoli A, Grace IM, McLaughlin M, Nichols RJ, Xu B, Lambert CJ, Higgins SJ. Charge transfer complexation boosts molecular conductance through Fermi level pinning. Chem Sci 2019; 10:2396-2403. [PMID: 30881668 PMCID: PMC6385675 DOI: 10.1039/c8sc04199g] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 01/02/2019] [Indexed: 11/21/2022] Open
Abstract
Interference features in the transmission spectra can dominate charge transport in metal-molecule-metal junctions when they occur close to the contact Fermi energy (E F). Here, we show that by forming a charge-transfer complex with tetracyanoethylene (TCNE) we can introduce new constructive interference features in the transmission profile of electron-rich, thiophene-based molecular wires that almost coincide with E F. Complexation can result in a large enhancement of junction conductance, with very efficient charge transport even at relatively large molecular lengths. For instance, we report a conductance of 10-3 G 0 (∼78 nS) for the ∼2 nm long α-quaterthiophene:TCNE complex, almost two orders of magnitude higher than the conductance of the bare molecular wire. As the conductance of the complexes is remarkably independent of features such as the molecular backbone and the nature of the contacts to the electrodes, our results strongly suggest that the interference features are consistently pinned near to the Fermi energy of the metallic leads. Theoretical studies indicate that the semi-occupied nature of the charge-transfer orbital is not only important in giving rise to the latter effect, but also could result in spin-dependent transport for the charge-transfer complexes. These results therefore present a simple yet effective way to increase charge transport efficiency in long and poorly conductive molecular wires, with important repercussions in single-entity thermoelectronics and spintronics.
Collapse
Affiliation(s)
- Kun Wang
- Department of Physics and Astronomy & NanoSEC , University of Georgia , 220 Riverbend Road , Athens , GA 30602 , USA .
| | - Andrea Vezzoli
- Department of Chemistry , University of Liverpool , Crown Street , Liverpool L69 7ZD , UK .
| | - Iain M Grace
- Department of Physics , Lancaster University , Lancaster LA1 4YB , UK .
| | - Maeve McLaughlin
- Department of Chemistry , University of Liverpool , Crown Street , Liverpool L69 7ZD , UK .
| | - Richard J Nichols
- Department of Chemistry , University of Liverpool , Crown Street , Liverpool L69 7ZD , UK .
| | - Bingqian Xu
- Department of Physics and Astronomy & NanoSEC , University of Georgia , 220 Riverbend Road , Athens , GA 30602 , USA .
- College of Engineering & NanoSEC , University of Georgia , 220 Riverbend Road , Athens , GA 30602 , USA
| | - Colin J Lambert
- Department of Physics , Lancaster University , Lancaster LA1 4YB , UK .
| | - Simon J Higgins
- Department of Chemistry , University of Liverpool , Crown Street , Liverpool L69 7ZD , UK .
| |
Collapse
|
2
|
Al-Backri A, Zólyomi V, Lambert CJ. Electronic properties of linear carbon chains: Resolving the controversy. J Chem Phys 2014; 140:104306. [DOI: 10.1063/1.4867635] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
3
|
Oroszlány L, Zólyomi V, Lambert CJ. Carbon nanotube Archimedes screws. ACS NANO 2010; 4:7363-7366. [PMID: 21126086 DOI: 10.1021/nn1020242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Recently, nanomechanical devices composed of a long stationary inner carbon nanotube and a shorter, slowly rotating outer tube have been fabricated. In this paper, we study the possibility of using such devices as nanoscale transducers of motion into electricity. When the outer tube is chiral, we show that such devices act like quantum Archimedes screws, which utilize mechanical energy to pump electrons between reservoirs. We calculate the pumped charge from one end of the inner tube to the other, driven by the rotation of a chiral outer nanotube. We show that the pumped charge can be greater than one electron per 360° rotation, and consequently, such a device operating with a rotational frequency of 10 MHz, for example, would deliver a current of ≈1 pAmp.
Collapse
Affiliation(s)
- László Oroszlány
- Physics Department, Lancaster University, LA1 4YB Lancaster, United Kingdom.
| | | | | |
Collapse
|
4
|
Leary E, Höbenreich H, Higgins SJ, van Zalinge H, Haiss W, Nichols RJ, Finch CM, Grace I, Lambert CJ, McGrath R, Smerdon J. Single-molecule solvation-shell sensing. PHYSICAL REVIEW LETTERS 2009; 102:086801. [PMID: 19257766 DOI: 10.1103/physrevlett.102.086801] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Indexed: 05/27/2023]
Abstract
We present a new route to single-molecule sensing via solvation shells surrounding a current-carrying backbone molecule. As an example, we show that the presence of a water solvation shell "gates" the conductance of a family of oligothiophene-containing molecular wires, and that the longer the oligothiophene, the larger is the effect. For the longest example studied, the molecular conductance is over 2 orders of magnitude larger in the presence of a shell comprising just 10 water molecules. A first principles theoretical investigation of electron transport through the molecules, using the nonequilibrium Green's function method, shows that water molecules interact directly with the thiophene rings, significantly shifting transport resonances and greatly increasing the conductance. This reversible effect is confirmed experimentally through conductance measurements performed in the presence of moist air and dry argon.
Collapse
Affiliation(s)
- E Leary
- Department of Chemistry, Liverpool University, Liverpool, L69 7ZD, United Kingdom
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
|
6
|
Carton JP, Pichard JL, Zanon N. Many-channel conductance of d-dimensional pure and randomly layered materials. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3719/19/21/009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
7
|
|
8
|
Heinrichs J. Eigenstates for an Anderson model of an ordered-lattice-disordered-lattice junction. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:5295-5304. [PMID: 9976870 DOI: 10.1103/physrevb.50.5295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
9
|
Ryu CS, Oh GY, Lee MH. Electronic properties of a tight-binding and a Kronig-Penney model of the Thue-Morse chain. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:132-141. [PMID: 10006760 DOI: 10.1103/physrevb.48.132] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
10
|
Luck JM. Cantor spectra and scaling of gap widths in deterministic aperiodic systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 39:5834-5849. [PMID: 9949002 DOI: 10.1103/physrevb.39.5834] [Citation(s) in RCA: 154] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
11
|
The one dimensional anderson model with off diagonal disorder: band centre anomaly. ACTA ACUST UNITED AC 1988. [DOI: 10.1007/bf01312150] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|