1
|
Electronic and transport properties of graphene nanoflakes with the protrusion of different widths. J Mol Model 2020; 26:229. [PMID: 32785788 DOI: 10.1007/s00894-020-04496-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 08/03/2020] [Indexed: 10/23/2022]
Abstract
Theoretical investigation on the transport properties of graphene nanoflakes (GNFs) with protrusions has been performed with density-functional calculations by considering the influence of the structural symmetry. It is found that GNFs with different widths of protrusions exhibit distinctly different transport properties, depending on whether they are mirror symmetric with respect to the midplane (σ) between the two edges. For the symmetric models, electrons primarily pass through the edges of the GNFs with a small transmission probability. On the contrary, the electrons prefer to transit along one side of the GNFs with a high probability in the asymmetric models. Therefore, the conductivity of asymmetric models is greater than that of symmetric models.
Collapse
|
2
|
First principle approach to elucidate transport properties through L-glutamic acid-based molecular devices using symmetrical electrodes. J Mol Model 2020; 26:74. [PMID: 32146585 DOI: 10.1007/s00894-020-4323-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 02/23/2020] [Indexed: 10/24/2022]
Abstract
Protein-based electronics is one of the emerging technology in which inventive electronic devices are being adduced and developed based on the selective actions of specific proteins. The explicit actions can be predicted if the building blocks of proteins (i.e., amino acids) are studied decorously. We emphasize our work on electronic transport properties of L-glutamic acid (i.e., L-amino acid) stringed to gold, silver, and copper electrodes, respectively, to form three distinct devices. For our calculations, we employ NEGF-DFT approach using self-consistent function. Electronic coupling and tunneling barriers between the molecule and the electrodes have been emphasized with an inception of delocalization of molecular orbitals within the device. We observe strong correlation between tunneling barrier and Mulliken charge transfer between molecule and electrodes. The asymmetrical carbon chain (-CH2) within the molecule exhibits negative differential resistance (NDR) and rectification ratio. The device using molecule with copper electrodes exhibits the highest peak to valley current ratio of 1.84. The rectification ratio of the device with gold, silver, and copper electrodes is 2.35, 2.25, and 15.62, respectively, at finite bias. These results yield fresh insight on the potential of L-glutamic acid like bio-molecule in the emerging field of proteotronics.
Collapse
|
3
|
Cheng N, Chen F, Durkan C, Wang N, He Y, Zhao J. Electron transport behavior of quinoidal heteroacene-based junctions: effective electron-transport pathways and quantum interference. Phys Chem Chem Phys 2018; 20:28860-28870. [PMID: 30420983 DOI: 10.1039/c8cp05901b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electron transport behavior through a series of molecular junctions composed of tetracene (TC) and S/O substituted-TC (S/O-TC) has been studied using density functional theory (DFT) combined with the non-equilibrium Green's function (NEGF) method. The unique transport behavior has been interpreted using correlated quantum interference and electron transport pathway models. In the TC system, two dominant electron transfer channels exist as demonstrated by a detailed transmission pathway analysis. In the substituted S/O-TC systems, the electron transport behavior is regulated through either constructive or destructive quantum interference due to the existence of additional p-electrons, leading to a significant diversity of current-voltage curves. Compared to the TC molecule in the bias region from 0 to 1.0 V, an α-connected molecular junction exhibits a greater current, whereas a β-connected molecular junction shows a smaller current. The substitution with O and S atoms shows a minor effect on the conductance of the molecular junctions. In order to clarify the role of heteroatoms, a series of artificial models designed by removing specific sulfur and carbon atoms in α-S-TC have been investigated in detail. The results have demonstrated that only the S heteroatom on one side of the molecule contributes to the junction conductivity through constructive quantum interference. It has also been observed that current exchange occurs between the two electron transfer channels.
Collapse
Affiliation(s)
- Na Cheng
- College of Material and Textile Engineering, China-Australia Institute for Advanced Materials and Manufacturing, Jiaxing University, Jiaxing 314001, China.
| | | | | | | | | | | |
Collapse
|
4
|
Cheng JF, Yan Q, Zhou L, Han Q, Gao L. The electron and spin polarized transport in wide-voltage-ranges through colbaltporphyrin-based molecular junctions. J Chem Phys 2016; 144:084707. [PMID: 26931718 DOI: 10.1063/1.4942923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The electron and spin polarized transport properties of Co benzene-porphyrin-benzene (BPB) molecule coupled to gold (Au) nanowires in a wide voltage range (0-3.0 V) are investigated. By successively removing the front-end Au atoms, we construct Au nanowires with different molecule-electrode contact symmetries. Multiple negative differential resistance (NDR) peaks emerge at different bias voltage regions. It is found that the low-voltage NDR effect at 0.4 V can only be found in the junctions with S-Au top bindings. High-bias NDR effects intrinsic to central molecule at 2.8 V are observed in all the six structures. In particular, both the electron and spin polarized current-voltage (I-V) curves depend strongly on the contact configurations between Co-BPB molecule and the Au electrodes. And the top-binding may result in spin dependent transport properties and will be the priority selection in the design of molecular devices.
Collapse
Affiliation(s)
- Jue-Fei Cheng
- College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
| | - Qiang Yan
- College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
| | - Liping Zhou
- College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
| | - Qin Han
- College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
| | - Lei Gao
- College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
| |
Collapse
|
5
|
Horsley JR, Yu J, Abell AD. The Correlation of Electrochemical Measurements and Molecular Junction Conductance Simulations in β-Strand Peptides. Chemistry 2015; 21:5926-33. [DOI: 10.1002/chem.201406451] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Indexed: 01/14/2023]
|
6
|
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.
Collapse
Affiliation(s)
- Hongmei Liu
- Institute of Condensed Matter Physics, Linyi University, Shuangling Road, Linyi 276000, P. R. China
| | | | | | | | | |
Collapse
|
7
|
Abstract
Looking for single molecule electronic devices, we have investigated the charge transport properties of individual tetra-phenylporphyrin molecules on different substrates by ultrahigh-vacuum scanning tunneling microscopy and spectroscopy and by first-principles calculations. The tetra-phenylporphyrins with a Co atom (Co-TPP) or 2 hydrogens (H2-TPP) in the central macrocycle when deposited on Cu3Au(100) substrates showed a diode-like behavior with p and n type character, respectively. After removing the central hydrogens of H2-TPP molecule with the STM tip an ohmic behavior was measured. The rectifying effect was understood from the theoretical point of view by assuming for Co-TPP HOMO conduction and for H2-TPP LUMO conduction, both selectively elected by the hybridization of states between molecule and substrate surface.
Collapse
|
8
|
Lan TN. Electronic transport properties of molecular junctions based on the direct binding of aromatic ring to electrodes. Chem Phys 2014. [DOI: 10.1016/j.chemphys.2013.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
9
|
Weng T, DeBrincat D, Arcisauskaite V, McGrady JE. In search of structure–function relationships in transition-metal based rectifiers. Inorg Chem Front 2014. [DOI: 10.1039/c4qi00038b] [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
Using the paramagnetic moment of transition metal ions to tune the transparency of molecule–electrode heterojunctions holds the key to controlling current rectification.
Collapse
Affiliation(s)
- Tingting Weng
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei, China
| | | | | | | |
Collapse
|
10
|
Liu H, Wang H, Zhao J, Kiguchi M. Molecular rectification in triangularly shaped graphene nanoribbons. J Comput Chem 2013; 34:360-5. [PMID: 23081769 DOI: 10.1002/jcc.23142] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 08/16/2012] [Accepted: 09/11/2012] [Indexed: 11/08/2022]
Abstract
We present a theoretical study of electron transport in tailored zigzag graphene nanoribbons (ZGNRs) with triangular structure using density functional theory together with the nonequilibrium Green's function formalism. We find significant rectification with a favorite electron transfer direction from the vertex to the right edge. The triangular ZGNR connecting to the electrode with one thiol group at each terminal shows an average rectification ratio of 8.4 over the bias range from -1.0 to 1.0 V. This asymmetric electron transport property originates from nearly zero band gap of triangular ZGNR under negative bias, whereas a band gap opens under positive bias. When the molecule is connected to the electrode by multithiol groups, the current is enhanced due to strong interfacial coupling; however, the rectification ratio decreases. The simulation results indicate that the unique electronic states of triangular ZGNR are responsible for rectification, rather than the asymmetric anchoring groups.
Collapse
Affiliation(s)
- Hongmei Liu
- Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210008, People's Republic of China
| | | | | | | |
Collapse
|
11
|
Liu H, Wang N, Li P, Yin X, Yu C, Gao N, Zhao J. Theoretical investigation into molecular diodes integrated in series using the non-equilibrium Green's function method. Phys Chem Chem Phys 2011; 13:1301-6. [DOI: 10.1039/c0cp00118j] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
12
|
Gao N, Liu H, Yu C, Wang N, Zhao J, Xie H. Asymmetric electron transport through a conjugated–saturated hydrocarbon molecular wire. COMPUT THEOR CHEM 2011. [DOI: 10.1016/j.comptc.2010.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
13
|
Zhou KG, Zhang YH, Wang LJ, Xie KF, Xiong YQ, Zhang HL, Wang CW. Can azulene-like molecules function as substitution-free molecular rectifiers? Phys Chem Chem Phys 2011; 13:15882-90. [DOI: 10.1039/c0cp02693j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
14
|
Liu H, Yu C, Gao N, Zhao J. The diversity of electron-transport behaviors of molecular junctions: correlation with the electron-transport pathway. Chemphyschem 2010; 11:1895-902. [PMID: 20379983 DOI: 10.1002/cphc.201000092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We report the electron-transport behaviors of a number of molecular junctions composed of pi-conjugated molecular wires. From calculations performed by using density functional theory (DFT) combined with the non-equilibrium Green's function (NEGF) method, we found that the length-conductivity relations are diverse, depending on the particular molecular structures. The results reveal that the conductance-length dependence follows an exponential law for many conjugated molecules with a single channel, such as oligothiophene, oligopyrrole and oligophenylene. Therefore, a quantitative relation between the energy gap (E(g))(infinity) of the molecular wire and the attenuation factor beta can be defined. However, when the molecular wires have multichannels, the decay of conductance does not follow the exponential relation. For example, the conductance of porphyrin-based oligomers and fused thiophene decays almost linearly. The diversity of electron-transport behaviors of molecular junctions is directly dominated by the electron-transport pathway.
Collapse
Affiliation(s)
- Hongmei Liu
- Key laboratory of Analytical Chemistry for Life Science (Ministry of Education), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210008, PR China
| | | | | | | |
Collapse
|