A Continuous Electrical Conductivity Model for Monolayer Graphene From Near Intrinsic to Far Extrinsic Region

2014 ◽  
Vol 61 (11) ◽  
pp. 3646-3653 ◽  
Author(s):  
Sitangshu Bhattacharya ◽  
Dipankar Saha ◽  
Aveek Bid ◽  
Santanu Mahapatra
Keyword(s):  
Electrical Conductivity ◽  
Monolayer Graphene ◽  
Conductivity Model

Simple and environment-friendly method for graphene synthesis by using ultrasound.

2021 ◽  
Vol 17 ◽  
Author(s):  
Irena Markovska ◽  
Dimitar Georgiev ◽  
Fila Yovkova ◽  
Miroslav Abrashev
Keyword(s):  
Electrical Conductivity ◽  
Raman Spectroscopy ◽  
Monolayer Graphene ◽  
Conductivity Measurements ◽  
Environment Friendly ◽  
Complex Processes ◽  
Graphene Synthesis ◽  
Pure Graphite ◽  
Ft Ir ◽  
Electrodes For Supercapacitors

Background: This paper proposes a technology for the production of monolayer graphene by an easy, accessible, and non-toxic method. Methods: For the preparation of graphene, a combination of chemical and physical (ultrasonic) treatment of the original graphite precursor (purity >99%) was applied. The precursor of graphite is placed in a beaker with a solution of KOH or H2SO4. The mixtures were homogenized well and sonicated for 4h. The applied ultrasound has a power of 120 W, frequency 40 kHz. Due to the effects of ultrasound, complex processes take place in the solutions, which leads to the formation of superfine graphene. Better results were obtained at samples treated with 2n H2SO4. The physicochemical properties of the resulting graphene were characterized mainly by Raman spectroscopy, FT-IR, TEM, SEM, and electrical conductivity measurements. Results: Our research was focused mainly on the field of nanotechnology, in particular on the synthesis of graphene, which could be used as a coating on electrodes for supercapacitors. In this connection, three series of samples were developed in which the pristine graphite was treated with 2n H2SO4, 4n H2SO4, and 6n H2SO4, respectively, and their electrical properties were measured. Conclusion: The obtained graphene shows electrical resistivity 2-3 times lower than that of the precursor of pure graphite.

scholarly journals An electrical conductivity model for fractal porous media

2015 ◽  
Vol 42 (12) ◽  
pp. 4833-4840 ◽  
Author(s):  
Wei Wei ◽  
Jianchao Cai ◽  
Xiangyun Hu ◽  
Qi Han
Keyword(s):  
Electrical Conductivity ◽  
Porous Media ◽  
Conductivity Model

scholarly journals Measurements of the Electrical Conductivity of Monolayer Graphene Flakes Using Conductive Atomic Force Microscopy

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2575
Author(s):  
Soomook Lim ◽  
Hyunsoo Park ◽  
Go Yamamoto ◽  
Changgu Lee ◽  
Ji Won Suk
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Monolayer Graphene ◽  
Synthesis Methods ◽  
Clear Understanding ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Flakes

The intrinsic electrical conductivity of graphene is one of the key factors affecting the electrical conductance of its assemblies, such as papers, films, powders, and composites. Here, the local electrical conductivity of the individual graphene flakes was investigated using conductive atomic force microscopy (C-AFM). An isolated graphene flake connected to a pre-fabricated electrode was scanned using an electrically biased tip, which generated a current map over the flake area. The current change as a function of the distance between the tip and the electrode was analyzed analytically to estimate the contact resistance as well as the local conductivity of the flake. This method was applied to characterize graphene materials obtained using two representative large-scale synthesis methods. Monolayer graphene flakes synthesized by chemical vapor deposition on copper exhibited an electrical conductivity of 1.46 ± 0.82 × 106 S/m. Reduced graphene oxide (rGO) flakes obtained by thermal annealing of graphene oxide at 300 and 600 °C exhibited electrical conductivities of 2.3 ± 1.0 and 14.6 ± 5.5 S/m, respectively, showing the effect of thermal reduction on the electrical conductivity of rGO flakes. This study demonstrates an alternative method to characterizing the intrinsic electrical conductivity of graphene-based materials, which affords a clear understanding of the local properties of individual graphene flakes.

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