Graphene, a single-atom-thick sheet of carbon atoms arranged in a hexagonal lattice, is renowned for its exceptional electrical conductivity, which surpasses even that of copper. This remarkable property of graphene has captured the attention of scientists, engineers, and technologists worldwide, as it holds immense potential for revolutionizing various industries, from electronics to energy storage.
Electrical Conductivity of Graphene
The electrical conductivity of graphene is primarily attributed to the unique electronic structure of the material. Graphene’s carbon atoms are arranged in a honeycomb-like structure, with each carbon atom forming three covalent bonds with its neighboring atoms. This arrangement leaves one electron per carbon atom free to move throughout the material, creating a delocalized electron system.
These delocalized electrons are responsible for graphene’s high electrical conductivity, which can be quantified using the following formula:
σ = n * e * μ
Where:
– σ
is the electrical conductivity of the material
– n
is the charge carrier concentration
– e
is the elementary charge of an electron
– μ
is the charge carrier mobility
In the case of graphene, the charge carrier concentration n
is typically high, and the charge carrier mobility μ
is exceptionally high, reaching values of up to 200,000 cm^2/V·s at room temperature. This combination of high charge carrier concentration and mobility results in an electrical conductivity that is approximately 70% higher than that of copper on a nanoscale.
Factors Affecting Graphene’s Electrical Conductivity
The electrical conductivity of graphene can be influenced by several factors, including:
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Purity: The presence of impurities or defects in the graphene structure can disrupt the flow of electrons, reducing the overall electrical conductivity.
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Doping: Introducing foreign atoms or molecules (known as dopants) into the graphene lattice can alter the charge carrier concentration, either increasing or decreasing the electrical conductivity.
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Environmental Conditions: The surrounding environment, such as temperature, pressure, and the presence of adsorbates, can affect the charge carrier mobility and concentration in graphene, thereby influencing its electrical conductivity.
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Structural Modifications: Techniques like chemical functionalization, strain engineering, or the creation of graphene nanostructures can be used to tailor the electronic properties of graphene, including its electrical conductivity.
Graphene’s Electrical Conductivity on a Macroscale
While graphene’s electrical conductivity is exceptional on a nanoscale, it is also essential to consider its performance on a macroscale. On a macroscale, graphene can achieve an electrical conductivity of up to 80 MS/m, which is significantly higher than that of copper (59.6 MS/m).
This high electrical conductivity of macroscale graphene enables several advantages, including:
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Efficiency Gains: The superior conductivity of graphene can lead to reduced energy losses and improved efficiency in various electrical and electronic applications.
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Weight and Volume Savings: Graphene’s high conductivity-to-weight ratio allows for the design of lighter and more compact electrical components, which is particularly important in applications such as electric vehicles and portable electronics.
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New Design Possibilities: The exceptional electrical properties of graphene open up new design possibilities for powertrains, motors, and other electrical systems, enabling more efficient and innovative solutions.
Thermal Conductivity of Graphene
In addition to its exceptional electrical conductivity, graphene also exhibits remarkable thermal conductivity. At room temperature, graphene can exhibit a thermal conductivity of up to 5000 W/m·K, which is significantly higher than that of copper (401 W/m·K).
The high thermal conductivity of graphene is attributed to the strong covalent bonds between the carbon atoms and the efficient transfer of phonons (lattice vibrations) through the material. This property makes graphene a promising material for thermal management applications, such as heat sinks, thermal interface materials, and thermal insulators.
Practical Applications of Graphene’s Electrical Conductivity
The exceptional electrical conductivity of graphene has led to its exploration and utilization in a wide range of practical applications, including:
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Electronics and Microelectronics: Graphene’s high carrier mobility and conductivity make it a promising material for high-speed electronic devices, such as transistors, interconnects, and radio-frequency (RF) components.
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Energy Storage and Conversion: Graphene’s conductivity and surface area make it an attractive material for use in energy storage devices like supercapacitors and lithium-ion batteries, as well as in fuel cells and solar cells.
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Sensors and Detectors: The sensitivity of graphene’s electrical properties to various stimuli, such as chemical, biological, and physical changes, enables its use in a wide range of sensor applications, including gas sensors, biosensors, and pressure sensors.
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Transparent Conductive Coatings: Graphene’s high electrical conductivity and optical transparency make it a suitable material for transparent conductive coatings, which can be used in applications like touch screens, displays, and solar cells.
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Electromagnetic Interference (EMI) Shielding: The high electrical conductivity of graphene allows it to effectively block and absorb electromagnetic radiation, making it a promising material for EMI shielding applications in electronic devices and systems.
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Flexible and Wearable Electronics: The combination of graphene’s electrical conductivity, flexibility, and mechanical strength enables its use in the development of flexible and wearable electronic devices, such as bendable displays, smart textiles, and conformable sensors.
Conclusion
Graphene’s exceptional electrical conductivity, which surpasses even that of copper, has positioned it as a revolutionary material with immense potential for transforming various industries. From electronics and energy storage to thermal management and sensor applications, the unique properties of graphene continue to inspire researchers and engineers to explore new frontiers in technology. As the understanding and control of graphene’s electrical characteristics continue to advance, the future holds exciting possibilities for the widespread adoption and integration of this remarkable material in a wide range of practical applications.
References:
- Nanografi – What is Graphene? The Ultimate Guide
- Bosch – Can Graphene Compete with Copper in Electrical Conductivity?
- Chemistry Stack Exchange – How is Graphene Electrically Conductive?
- Nature – Thermal and Electrical Conductivity of Pristine Graphene
- ACS Nano – Electrical Properties and Applications of Graphene
Hi, I’m Akshita Mapari. I have done M.Sc. in Physics. I have worked on projects like Numerical modeling of winds and waves during cyclone, Physics of toys and mechanized thrill machines in amusement park based on Classical Mechanics. I have pursued a course on Arduino and have accomplished some mini projects on Arduino UNO. I always like to explore new zones in the field of science. I personally believe that learning is more enthusiastic when learnt with creativity. Apart from this, I like to read, travel, strumming on guitar, identifying rocks and strata, photography and playing chess.