scholarly journals The Effect of Hydrogen on the Electrical Properties of the Graphene Nanomeshes

2020 ◽  
Vol 6 (2) ◽  
pp. 35
Author(s):  
Pavel V. Barkov ◽  
Michael M. Slepchenkov ◽  
Olga E. Glukhova
Keyword(s):  
Electrical Conductivity ◽  
Energy Gap ◽  
Electronic Conductivity ◽  
Electron Work Function ◽  
Current Transfer ◽  
Hydrogen Atoms ◽  
Turn On ◽  
Hydrogenated Graphene ◽  
In Silico Study ◽  
Graphene Nanomesh

This paper is devoted to the in silico study of the electronic properties and electrical conductivity of hydrogenated graphene nanomesh (GNM). It is found that the conductivity of GNM can be controlled by varying the type of hydrogenation. Due to the hydrogenation of the nanohole edges by one or two hydrogen atoms, the energy gap can be changed, the anisotropy of the electrical conductivity can be enhanced, and the electron work function can be controlled. By varying the type of hydrogenation, it is possible to form conductive and insulating paths on 2D GNM. Thus, a certain combination of the sp2- and sp3-topologies of the GNM edge atoms allows one to fully “turn off” the electronic conductivity in all directions or, conversely, “turn on” the desired direction for current transfer.

Regularities of Electrical Conductivity of Monolayer Graphene Nanomesh with Round Holes

2021 ◽  
Vol 23 (5) ◽  
pp. 231-237
Author(s):  
O.E. Glukhova ◽  
◽  
M.M. Slepchenkov ◽  
P.V. Barkov ◽  
◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Energy Gap ◽  
Monolayer Graphene ◽  
Current Transfer ◽  
Neck Width ◽  
Zigzag Direction ◽  
Circular Holes ◽  
Graphene Nanomesh ◽  
Density Of Electron States ◽  
Armchair Direction

This paper studies graphene nanomesh with different neck width is the smallest distance between two neighboring holes. The electrical properties of graphene nanomesh with circular holes were calculated in dependence on its neck width. For the considered structures energetical characteristics including energy gap (Egap), Fermi level (Ef), and density of electron states (DOS) were found. It was established that graphene nanomesh demonstrated both metallic and semiconductor types of conductivity when the neck width was increased along the zigzag direction. In the case of increasing the neck width along armchair direction, graphene nanomesh demonstrated only a metallic type of conductivity. It was observed the anisotropy of electrical conductivity depending on the direction along which the current transfer was carried out.

scholarly journals Holey Graphene: Topological Control of Electronic Properties and Electric Conductivity

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1074
Author(s):  
Pavel V. Barkov ◽  
Olga E. Glukhova
Keyword(s):  
Electrical Conductivity ◽  
Fermi Level ◽  
Electric Conductivity ◽  
Energy Gap ◽  
Local Density ◽  
Electronic States ◽  
Current Transfer ◽  
Neck Width ◽  
Density Of Electronic States ◽  
Semiconductor Type

This paper studies holey graphene with various neck widths (the smallest distance between two neighbor holes). For the considered structures, the energy gap, the Fermi level, the density of electronic states, and the distribution of the local density of electronic states (LDOS) were found. The electroconductive properties of holey graphene with round holes were calculated depending on the neck width. It was found that, depending on the neck width, holey graphene demonstrated a semiconductor type of conductivity with an energy gap varying in the range of 0.01–0.37 eV. It was also shown that by changing the neck width, it is possible to control the electrical conductivity of holey graphene. The anisotropy of holey graphene electrical conductivity was observed depending on the direction of the current transfer.

Revisiting the passivation of stainless steels and other passive CRAs

2018 ◽  
Vol 106 (1) ◽  
pp. 107 ◽  
Author(s):  
Jean- Louis Crolet
Keyword(s):  
Electrical Conductivity ◽  
Metal Ions ◽  
Base Metal ◽  
Stainless Steels ◽  
Electronic Conductivity ◽  
Transport Processes ◽  
General Knowledge ◽  
Inorganic Polymers ◽  
Faraday Cage

All that was said so far about passivity and passivation was indeed based on electrochemical prejudgments, and all based on unverified postulates. However, due the authors’ fame and for lack of anything better, the great many contradictions were carefully ignored. However, when resuming from raw experimental facts and the present general knowledge, it now appears that passivation always begins by the precipitation of a metallic hydroxide gel. Therefore, all the protectiveness mechanisms already known for porous corrosion layers apply, so that this outstanding protectiveness is indeed governed by the chemistry of transport processes throughout the entrapped water. For Al type passivation, the base metal ions only have deep and complete electronic shells, which precludes any electronic conductivity. Then protectiveness can only arise from gel thickening and densification. For Fe type passivation, an incomplete shell of superficial 3d electrons allows an early metallic or semimetallic conductivity in the gel skeleton, at the onset of the very first perfectly ordered inorganic polymers (- MII-O-MIII-O-)n. Then all depends on the acquisition, maintenance or loss of a sufficient electrical conductivity in this Faraday cage. But for both types of passive layers, all the known features can be explained by the chemistry of transport processes, with neither exception nor contradiction.

scholarly journals Fabrication of Graphene Nanomesh FET Terahertz Detector

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 641
Author(s):  
Yuan Zhai ◽  
Yi Xiang ◽  
Weiqing Yuan ◽  
Gang Chen ◽  
Jinliang Shi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Energy Gap ◽  
Coupling Efficiency ◽  
High Sensitivity ◽  
Fabrication Process ◽  
Monolayer Graphene ◽  
Terahertz Waves ◽  
Wet Process ◽  
Graphene Nanomesh ◽  
Thz Detector

High sensitivity detection of terahertz waves can be achieved with a graphene nanomesh as grating to improve the coupling efficiency of the incident terahertz waves and using a graphene nanostructure energy gap to enhance the excitation of plasmon. Herein, the fabrication process of the FET THz detector based on the rectangular GNM (r-GNM) is designed, and the THz detector is developed, including the CVD growth and the wet-process transfer of high quality monolayer graphene films, preparation of r-GNM by electron-beam lithography and oxygen plasma etching, and the fabrication of the gate electrodes on the Si3N4 dielectric layer. The problem that the conductive metal is easy to peel off during the fabrication process of the GNM THz device is mainly discussed. The photoelectric performance of the detector was tested at room temperature. The experimental results show that the sensitivity of the detector is 2.5 A/W (@ 3 THz) at room temperature.

Electrical Properties of Y0.06Sr0.94Ti0.6Fe0.4O3-δ-YSZ Composites as Electrode Materials

2016 ◽  
Vol 697 ◽  
pp. 327-330 ◽  
Author(s):  
Ke Shan ◽  
Xing Min Guo ◽  
Feng Rui Zhai ◽  
Zhong Zhou Yi
Keyword(s):  
Electrical Conductivity ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
Ionic Conductivities ◽  
Conductivity Measurement ◽  
Transference Numbers ◽  
Secondary Phases ◽  
Electrical Conductivity Measurement ◽  
Total Electrical Conductivity ◽  
Phase Compatibility

Y0.06Sr0.94Ti0.6Fe0.4O3-δ-YSZ composites were prepared by mixing Y, Fe co-doped SrTiO3 (Y0.06Sr0.94Ti0.6Fe0.4O3-δ known as YSTF) and 8 mol% Y2O3 stabilized ZrO2 (YSZ) in different weight fractions. The phase stability, phase compatibility, microstructure and mixed ionic-electronic conductivity of composites were investigated. Phase analysis by XRD showed no clearly detectable secondary phases. The electrical conductivity measurement on the YSTF-YSZ composites showed a drastic decrease in total electrical and ionic conductivities when more than 10 wt% of YSZ was used in the composites. The total electrical conductivity was 0.102 S/cm for Y0.06Sr0.94Ti0.6Fe0.4O3-δ and 0.043 S/cm for YSTF-20YSZ at 700 oC, respectively. The value at 700 oC is approximately 2.4 times higher than that of YSTF-20YSZ. The ionic conductivity of Y0.06Sr0.94Ti0.8Fe0.2O3-δ varies from 0.015S/cm at 700 oC to 0.02 S/cm at 800 oC, respectively. The value at 800°C is approximately 12.5 times higher than YSTF-20YSZ. The ion transference numbers of YSTF-YSZ composites vary from 0.14 to 0.28 at 800 °C.

scholarly journals 5-Methyl-1,3-phenylene bis[5-(dimethylamino)naphthalene-1-sulfonate]: crystal structure and DFT calculations

2019 ◽  
Vol 75 (7) ◽  
pp. 1079-1083
Author(s):  
Tanwawan Duangthongyou ◽  
Ramida Rattanakam ◽  
Kittipong Chainok ◽  
Songwut Suramitr ◽  
Thawatchai Tuntulani ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Energy Gap ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Hydrogen Atoms ◽  
Lumo Energy ◽  
Compound C ◽  
Dansyl Group ◽  
Weak Hydrogen Bonds ◽  
Homo Lumo

The title compound, C31H30N2S2O6, possesses crystallographically imposed twofold symmetry with the two C atoms of the central benzene ring and the C atom of its methyl substituent lying on the twofold rotation axis. The two dansyl groups are twisted away from the plane of methylphenyl bridging unit in opposite directions. The three-dimensional arrangement in the crystal is mainly stabilized by weak hydrogen bonds between the sulfonyl oxygen atoms and the hydrogen atoms from the N-methyl groups. Stacking of the dansyl group is not observed. From the DFT calculations, the HOMO–LUMO energy gap was found to be 2.99 eV and indicates n→π* and π→π* transitions within the molecule.

STUDYING MULTILAYERED GRAPHENES BY ELECTROPHYSICAL METHODS

2021 ◽  
pp. 100-107
Author(s):  
K. L. Levine ◽  
D. V. Ryabokon ◽  
S. D. Khanin ◽  
R. V. Gelamo ◽  
N. A. Nikonorova
Keyword(s):  
Electrical Conductivity ◽  
Chemical Composition ◽  
Electrical Properties ◽  
Work Function ◽  
Electron Work Function ◽  
Charge Storage ◽  
High Electrical Conductivity ◽  
Free Standing ◽  
Storage Devices

The paper studies multilayer graphenes in the form of free-standing films. The authors provide data about the morphology and electrical properties of films treated with plasma of various chemical composition. It is shown that it is possible to control the electrical properties of the surface and electron work function without significantly affecting its morphology. The obtained samples, combining mechanical flexibility with unreactiveness and high electrical conductivity, are promising for application in flexible charge storage devices.

Coordination polymer-based conductive materials: ionic conductivity vs. electronic conductivity

2019 ◽  
Vol 7 (42) ◽  
pp. 24059-24091 ◽  
Author(s):  
Hai-Ning Wang ◽  
Xing Meng ◽  
Long-Zhang Dong ◽  
Yifa Chen ◽  
Shun-Li Li ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Coordination Polymer ◽  
Coordination Polymers ◽  
Electronic Conductivity ◽  
Structural Factors ◽  
Conductive Materials ◽  
Recent Developments

This review summarizes recent developments of coordination polymers and their derivatives for ionic and electrical conductivity with the discussion about synthetic strategies and possible mechanisms to identify the key structural factors.

scholarly journals Transport Processes in TlI and in the AgI-TlI-System

1974 ◽  
Vol 29 (5) ◽  
pp. 782-785
Author(s):  
A. Sdiiraldi ◽  
A. Magistris ◽  
E. Pezzati
Keyword(s):  
Electrical Conductivity ◽  
Transport Properties ◽  
Electronic Conductivity ◽  
Ionic Transport ◽  
Transport Processes ◽  
Silver Ion ◽  
Transport Numbers ◽  
Bond Ionicity ◽  
High Electronic Conductivity ◽  
High Silver

Abstract The transport properties of TlI and of the system AgI -TlI were investigated by measuring the electrical conductivity, σ , and the electronic and ionic transport numbers. A particularly high electronic conductivity was detected in β-TlI, while the a phase showed a predominant anionic contribution, as in TlCl and TlBr. The intermediate compounds, AgTl2I3 and AgTlI2, are silver ion conductors, but they exhibit low σ values. A comparison with other poliiodides, with a high silver ion conductivity, is suggested on the basis of the crystal bond ionicity.

Amplifying fluorescent conjugated polymer sensor for singlet oxygen detection

2019 ◽  
Vol 55 (61) ◽  
pp. 8955-8958 ◽  
Author(s):  
Chun-Han Wang ◽  
Evgueni E. Nesterov
Keyword(s):  
Singlet Oxygen ◽  
Conjugated Polymer ◽  
Energy Gap ◽  
Fluorescent Sensor ◽  
Oxygen Detection ◽  
Turn On

A “higher energy gap” concept was used to design an efficient conjugated polymer turn-on amplifying fluorescent sensor for singlet oxygen.

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