Top 50 Graphene Manufacturers

Here is an expanded list of 50 notable graphene manufacturers and suppliers worldwide, reflecting the industry’s landscape as of 2025. These companies are recognized for their contributions to graphene production, innovation, and application development across various sectors.

Top 50 Graphene Manufacturers (2025)

United States

Carbon Rivers – Specializes in graphene-enhanced composites and coatings.
MATEXCEL – Offers graphene and other advanced materials for research and industrial use.
NanoIntegris Technologies, Inc. – Provides high-purity graphene materials, including single-layer graphene and graphene oxide.
Alfa Chemistry – Supplies a wide range of graphene products for various applications.
Goodfellow – Offers graphene materials for research and development purposes.
Nanotech Energy – Develops graphene-based energy storage solutions, including batteries and supercapacitors.
Reade Advanced Materials – Provides a variety of graphene materials for industrial applications.
Graphene Supermarket – Specializes in producing various graphene products, including graphene oxide and nanoplatelets.
GrapheneCA – Develops eco-friendly and cost-effective graphene solutions for industries like concrete, filtration, and energy storage.
Graphene Laboratories Inc. – Offers a wide range of graphene products backed by a highly experienced team.
Graphene America – Focuses on high-volume graphene manufacturing for applications like concrete and ballistic armor.
Graphene Layers – Produces graphene oxide and graphene-based composites, emphasizing sustainability and high quality.
General Graphene – Provides industrial-scale chemical vapor deposition (CVD) graphene for various applications.
Grolltex – Specializes in creating high-quality single-layer graphene using advanced methods.
SurgePower Materials – Produces high-purity, monolayer plant-based graphene with applications in various industries.
Graphene Networks – Focuses on next-generation WAN edge infrastructure using graphene technology.
Ressinea – Specializes in graphene resin products, enhancing strength and durability in materials.

Canada

NanoXplore Inc. – A large-scale graphene producer specializing in graphene powder and composite materials.
Graphene Manufacturing Group (GMG) – Develops energy-saving products using graphene, including batteries and lubricants.
Black Swan Graphene – Focuses on the production and commercialization of graphene nanoplatelets.

United Kingdom

First Graphene – Supplies high-quality graphene products with a robust manufacturing platform.
Haydale Graphene Industries – Offers functionalized graphene materials for composites, inks, and coatings.
Versarien plc – Provides graphene solutions for various industries, including construction and textiles.
Paragraf – Specializes in graphene-based semiconductors and electronic devices.

Australia

Talga Group – Integrates graphene production with graphite mining, focusing on battery and coating applications.

Singapore

2DM – Produces and markets graphene flakes for various applications.

Sweden

2D Fab AB – Manufactures graphene flakes using graphite from Swedish sources, focusing on scalable production.

China

2D Carbon Tech – Offers CVD-produced graphene films and graphene-based touch panels.
The Sixth Element (Changzhou) Materials Technology Co. Ltd – Provides graphene materials for coatings, composites, and energy storage.

France

Graphene Production – The largest European producer of graphene, with a production capacity of 90 tons per year.

India

GraphenEra Carbon Pvt. Ltd. – Produces and supplies high-quality graphene in bulk for various industries.

Spain

Graphenea – Offers custom manufacturing services for graphene-based devices, supporting both industrial and research needs.

Italy

Directa Plus – Produces graphene-based products for textiles, environmental remediation, and road surfacing.

Germany

GrapheneTech – Specializes in the production of high-purity graphene, offering it in both powder form and various dispersions.

Denmark

2D ApS – Provides single-layer and multilayered CVD graphene sheets on sacrificial polymer sheets for various applications.

Additional Notable Companies

Universal Matter – Develops turbostratic graphene for various applications.
Avadain – Produces large flake graphene for industrial uses.
Vitrotem – Specializes in graphene liquid cell assembly automation.
INBRAIN Neuroelectronics – Develops neural interface platforms using graphene.
GRAFTA Nanotech – Focuses on water contaminant adsorbent technologies using graphene.
Tenutec – Offers thermal management solutions enhanced by graphene.
Sensfit – Develops sensor technology incorporating graphene materials.
Granode – Produces battery anode materials utilizing graphene.
Danish Graphene – Manufactures functionalized and green graphene for various applications.
Graphene Flagship – A European initiative that brings together academic and industrial researchers to develop graphene technologies.
NIPPON SHOKUBAI CO., LTD. – Engages in the production of graphene materials for various applications.
MilliporeSigma – Provides graphene products for research and development.
Graphene One LLC – Developed the Kyrene® graphene material with excellent performance characteristics.

Graphene University List

UNIVERSITIES

What is Difference among Activated Carbon, Graphite, Graphene and Fullerence ?

Charcoal and Activated Carbons

A black, porous, carbonaceous material, 85 to 98 percent carbon, produced by the destructive distillation of wood and used as a fuel, filter, and adsorbent. Charcoal is amorphous and porous carbon, it contains almost no graphite phase and it may contain partially carbonized organizing substances as well as tar and mineral all of these varying tremendously with the source used to generate the Charcoal. Activated carbon is similar but it has been prepared from substrates carefully selected to yield a very high porosity. Some forms come from carbonizing carbohydrate substrates like starch or celluloid yielding very low mineral content. Activated carbon is a kind of black porous solid carbon, by coal by grinding, molding or with uniform coal particles by carbonization, activation of production.

Graphite

A soft crystalline allotrope of carbon, composed of graphene layers, having a steel-gray to black metallic luster and agreasy feel, used in lead pencils, lubricants, paints and coatings, and fabricated into a variety of forms such as molds,bricks, electrodes, crucibles, and rocket nozzles. Graphite is 3D

A soft crystalline allotrope of carbon, composed of graphene layers, having a steel-gray to black metallic luster and agreasy feel, used in lead pencils, lubricants, paints and coatings, and fabricated into a variety of forms such as molds, bricks, electrodes, crucibles, and rocket nozzles.

The chemical bonds in graphite are similar in strength to those found in diamond. However, the lattice structure of the carbon atoms contributes to the difference in hardness of these two compounds; graphite contains two dimensional lattice bonds, while diamond contains three dimensional lattice bonds. The carbon atoms within each layer of graphite contain weaker intermolecular bonds. This allows the layers to slide across each other, making graphite a soft and malleable material.

Various studies have demonstrated that graphite is an excellent mineral with several unique properties. It conducts heat and electricity and retains the highest natural strength and stiffness even in temperatures exceeding 3600°C. This material is self-lubricating and is also resistant to chemicals.

Although there are different forms of carbon, graphite is highly stable under standard conditions. Depending upon its form, graphite is utilized for a wide range of applications.

Graphene

A monolayer of carbon atoms having a hexagonal lattice structure and constituting a basic structural element ofgraphite, fullerenes, and carbon nanotubes. Graphene is 2D.

Graphene is the name for an atom-thick honeycomb sheet of carbon atoms. It is the building block for other graphitic materials (since a typical carbon atom has a diameter of about 0.33 nanometers, there are about 3 million layers of graphene in 1 mm of graphite).

Units of graphene are known as nanographene; these are tailored to specific functions and as such their fabrication process is more complicated than that of generic graphene. Nanographene is made by selectively removing hydrogen atoms from organic molecules of carbon and hydrogen, a process called dehydrogenation.

Harder than diamond yet more elestic than rubber; tougher than steel yet lighter than aluminium. Graphene is the strongest known material.

To put this in perspective: if a sheet of cling film (like kitchen wrap film) had the same strength as a pristine monolayer of graphene, it would require the force exerted by a mass of 2000 kg, or a large car, to puncture it with a pencil.

It is expected that, by strengthening standards and creating tailored high-quality materials, graphene will go beyond niche products and applications to broad market penetration by 2025. Then, graphene could be incorporated in ubiquitous commodities such as tyres, batteries and electronics. Graphene has unique properties that exceed those of graphite. Although graphite is often used to reinforce steel, it cannot be utilized as a structural material on its own because of its sheer planes. In contrast, graphene is the strongest material ever found; it is more than 40 times stronger than diamond and more than 300 times stronger than A36 structural steel.

What is the Difference between Graphite and Graphene ?

Since graphite has a planar structure, its electronic, acoustic, and thermal properties are highly anisotropic. This means, phonons pass much more easily along the planes than they do when trying to pass via the planes. However, graphene has very high electron mobility and, like graphite, is a good electrical conductor, due to the occurrence of a free pi (p) electron for each carbon atom.

However, graphene has much higher electrical conductivity than graphite, due to the occurrence of quasiparticles, which are electrons that function as if they have no mass and can travel long distances without scattering. In order to fully realize this high level of electrical conductivity, doping needs to be carried out to overcome the zero density of states which can be visualized at the Dirac points of graphene.

Fullerence

A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to seven atoms. The molecule may be a hollow sphere, ellipsoid, tube, or many other shapes and sizes. Graphene (isolated atomic layers of graphite), which is a flat mesh of regular hexagonal rings, can be seen as an extreme member of the family.

Fullerenes with a closed mesh topology are informally denoted by their empirical formula C_n, often written Cn, where n is the number of carbon atoms. However, for some values of n there may be more than one isomer.

The family is named after buckminsterfullerene (C₆₀), the most famous member, which in turn is named after Buckminster Fuller. The closed fullerenes, especially C₆₀, are also informally called buckyballs for their resemblance to the standard ball of association football (“soccer”). Nested closed fullerenes have been named bucky onions. Cylindrical fullerenes are also called carbon nanotubes or buckytubes. The bulk solid form of pure or mixed fullerenes is called fullerite.

Fullerenes had been predicted for some time, but only after their accidental synthesis in 1985 were they detected in nature and outer space. The discovery of fullerenes greatly expanded the number of known allotropes of carbon, which had previously been limited to graphite, diamond, and amorphous carbon such as soot and charcoal. They have been the subject of intense research, both for their chemistry and for their technological applications, especially in materials science, electronics, and nanotechnology.

What Are the Main Applications of Graphene ?

Graphene is a one-atom-thick sheet of carbon atoms arranged in a honeycomb-like pattern. Graphene is considered to be the world’s thinnest, strongest and most conductive material – of both electricity and heat. All of these properties are exciting researchers and businesses around the world – as graphene has the potential to revolutionize entire industries – in the fields of electricity, conductivity, energy generation, batteries, sensors and more.

Graphene is a disruptive technology; one that could open up new markets and even replace existing technologies or materials. It is when graphene is used both to improve an existing material and in a transformational capacity that its true potential can be realized.

Mechanical strength

Graphene is the world’s strongest material, and can be used to enhance the strength of other materials. Dozens of researchers have demonstrated that adding even a trace amount of graphene to plastics, metals or other materials can make these materials much stronger – or lighter (as you can use a smaller amount of material to achieve the same strength).

Such graphene-enhanced composite materials can find uses in aerospace, building materials, mobile devices, and many other applications.

The vast number of products, processes and industries for which graphene could create a significant impact all stems from its amazing properties.

No other material has the breadth of superlatives that graphene boasts, making it ideal for countless applications.

It is many times times stronger than steel, yet incredibly lightweight and flexible.
It is electrically and thermally conductive but also transparent.
It is the world’s first 2D material and is one million times thinner than the diameter of a single human hair.

What is the Applications of Graphene ?

Transport, medicine, electronics, energy, defence, desalination; the range of industries where graphene research is making an impact is substantial.

And this is only the start. These are only the first steps. The potential of graphene is limited only by our imagination.

1. Biomedical

Graphene’s unique properties allow for ground-breaking biomedical applications. Targeted drug delivery; improved brain penetration; DIY health-testing kits and ‘smart’ implants.

1. Graphene in Drug Delivery – Functionalized graphene can be used to carry chemotherapy drugs to tumors for cancer patients. Graphene based carriers targeted cancer cells better and reduced and decreased toxicity of the effected healthy cells. Drug delivery is not limited to cancer treatment, anti-inflammatory drugs have also been carried by graphene & chitosan combinations and yielded promising results.
2. Graphene in Cancer Treatment – Graphene can also detect cancer cells in the early stages of the disease. Moreover, it can stop them from growing any further in many types of cancer by intervening the correct formation of the tumor or causing autophagy which leads to the death of cancer cells.
3. Graphene in Gene Delivery – Gene delivery is a method used to cure some genetic diseases by bringing foreign DNA into cells. Graphene Oxide modified by Polyethyleneimine can be used for these purposes is expected to show low cytotoxicity, as it did in the drug delivery case.
4. Graphene in Photothermal Therapy – Photothermal therapy (PTT) is a approach used to eliminate abnormal cells in the targeted area of the body by irradiating a special agent which creates heat capable of destructing those cells. Graphene oxide increases effectiveness of PTT by a number of ways. First, it can be used to carry chemotherapeutic drugs to the tumor cells while they are being exposed to PTT simultaneously. Combining chemo and PTT like this is more effective than using one of these approaches alone. A nanocomposite of reduced graphene oxide (QD-CRGO) can be used during PTT for bioimaging of the cancer cells. Moreover, in their research, a group of scientists from Texas Tech and Texas A&M University have shown that using graphene oxide functionalized with biocompatible porphyrin as a platform for PTT for brain cancer have killed more cancer cells than PTT alone, while giving no harm to the healthy cells.
5. Graphene in Diabetes Monitoring – Scientists from the University of Bath have developed a blood glucose monitoring test which does not pierce the skin, unlike currently used finger prick tests. This patch, including a graphene sensor, is able to work on a small area containing at least one hair follicle. It detects the glucose by pulling it from the fluid present between the cells. This does not only end the painful methods of blood sugar monitoring, but is also expected to increase the accuracy of the results.
6. Graphene in Dialysis – Graphene membranes are not only useful for the energy, nuclear and food industries. A group of researchers from MIT showed that graphene can be used to filter the blood from wastes, drugs and chemicals as well. Graphene’s superiority in this case is that it is 20 times thinner than traditional membranes which leads to significant decrease in the time spent in the dialysis for the patients.
7. Graphene in Bone and Teeth Implantation – Hydroxyapatite, a form of calcium apatite, is a material used as a synthetic bone substitute for regenerated bone and dental tissues. Graphene, combined with Hydroxyapatite and Chitosan, have shown increase in the strength, corrosion resistance, flexibility and mechanical & osteogenic properties of the substitute when compared to HAp alone.
8. Graphene in Tissue Engineering and Cell Therapy – Bones are not the only tissue graphene can cure. Certain forms of graphene were shown to be compatible with human osteoblasts and human mesenchymal cells, showing similar properties with the cells’ physiological microenvironment. Cells grown with this method demonstrated better growth, proliferation, and differentiation while being ineffective on the cells’ viability. Stem cells are especially important in tissue reengineering to improve the lives of people with neuronal disorders or neurodegenerative diseases.
9. Graphene for the Brain – Mysteries about the brain haven’t been revealed completely yet. A graphene-based technology may allow scientists to uncover many of the unknowns by recording brains electrical activity. This new device is able to hear the frequencies below older technologies’ limits, and it doesn’t interfere with the functioning of the brain. Besides research on how the brain works, the technology can help the scientists to understand the reasons behind epilepsy seizures and develop treatments for the patients. Moreover, discovering more about the brain could lead to developing new Brain-Computer interfaces which are used in many areas including control of prosthetic limbs.
10. Graphene in HIV Diagnosis – Despite all the improvements, there are many drawbacks on current HIV diagnosis methods. They can either detect the antibodies in the body nearly a month later the patient was infected, or they can detect the virus itself however these methods take some time to process themselves and more expensive when compared to the antibody method. A biosensor made of silicon or graphene, containing Gold Nanoparticles was developed by Spanish National Research Council, which targets p24, an antigen found on HIV. The new method can detect the virus only a week after being infected and at levels 100,000 times lower than what the current tests can notice. Moreover, results of the test are ready within 5 hours of being tested
11. Graphene Biosensors – One of the advantages of graphene is its ability to detect minimal amounts of substances. Even a single molecule in a large volume can be detected with it. Biosensors made of graphene, graphene oxide or reduced graphene oxide show ultrasensitive properties when detecting DNA, ATP, dopamine, oligonucleotides, thrombin, and different atoms. There are several medical companies that already sell medical sensors made with graphene.
12. Graphene Bactericide – Graphene is a magnificent bactericidal material as it avoids the generation of microorganisms, such as bacteria, viruses, and fungi, by damaging their cell membranes between its outer layers. When compared to different derivatives of Graphene, Graphene Oxide and reduced Graphene Oxide shows the best antibacterial effects. GO can also be used as a compound with silver nanoparticles to increase antibacterial properties even further.
13. Graphene in Birth Control – Graphene has all the properties that is desired in a condom: it is flexible, extra strong and extremely thin. Researchers from Manchester University have worked on developing a “supercondom” made of graphene and latex combined. The research has received many funding, including one from Bill and Melinda Gates Foundation.
14. Graphene in Deaf-Mute Communication – A group of Chinese scientists have developed a wearable, bio-integrated device that can translate sign language into text and spoken language. The device uses graphene’s incredible conductivity and flexibility properties.
15. Graphene in Body Scans – Unlike X-rays, T-waves which can be used for body scanning are harmless to human body. However, there is a catch. T-waves, or THZ radiation, is hard to both detect and generate. The good news is, with the help of some modifications and other materials, CVD graphene can detect THZ radiation successfully. This will not only lead to safer body scans, but also incredibly faster internet in the future

2. Graphene-based composite materials

Graphene is a material with a huge amount of outstanding qualities; strength, flexibility, lightweight and conductivity.

1. Graphene in Shoes – Graphene sneakers? Yes, although in this case it is not used purely, other composite materials take advantage of it. In fact, it is claimed that a sole made of pure graphene could last hundreds of years. University of Manchester and sports brand Inov-8 developed a shoe using graphene which increases the outsoles’ strength and flexibility properties by 50%. These shoes are more durable and absorbs the impacts which could damage the bones and joints.
2. Graphene in Helmets – An ideal helmet would be strong, resistant to impact, durable, comfortable, and light. Graphene is incredibly strong, light, and flexible. It’s even used in bulletproof vests, so it can definitely resist impacts. With these properties, graphene is commercially used in motorbike helmets.
3. Graphene in Tires – Graphene is also used to make smarter tires and sports bike components. Adding graphene to bike’s tires apparently increases the puncture resistance and velocity, decreases rolling resistance and makes them way lighter, stronger, faster, and more resilient.
4. Graphene Clothes – The use of graphene fibers in fabrics offers antibacterial, and anti-static clothes which can preserve the heat and block UV. These fabrics can be used to create outdoor sportswear, pajamas for children that repel soil bacteria, or even household furniture to prevent the development of bacteria on its surface.
5. Graphene Rackets – Graphene can improve the energy distribution and weight of the racket while increasing the service speed and stability. Tennis equipment manufacturer Head have already developed a series of commercially available racket enhanced with graphene, named “Graphene 360” which is already used by tennis stars like Novak Djokovic and Sascha Zverev.
6. Graphene Electronic Tattoos and Fitness Tracking – Graphene Electronic Tattoo (GET) is developed by scientists at the University of Texas. First, they are more resistant to moisture, have a greater elasticity – with the ability to grow or shrink up to 40%, have a total thickness of 463 ± 30 nm, and have optical transparency of approximately 85%. They are like a second skin. These tattoos can be used to track heart rate, temperature, hydration levels, oxygen saturation and even the level of exposure to UV. Their application areas can vary from fitness tracking to medicine.

3. Electronics, Sensors, and Computers

Graphene has the potential to create the next-generation of electronics currently limited to sci-fi. Faster transistors; semiconductors; bendable phones and other electronics.

1. Graphene UV Sensors – UV sensors are used for detecting dangerous levels of ultra-violet radiation which can lead to skin problems or even cancer. However, it is not the only use of UV sensors, they are used in the military, optical communication, and environmental monitoring as well. On its own, graphene may not present a high photoresponsivity but when it is combined with other materials, they create flexible, transparent, environmentally-friendly and low-cost UV sensors which will lead to technologies such as wearable electronics in the close future.
2. Graphene Transistors – The new supertransistors, which replace silicon with graphene, can increase the speed of computers up to one thousand times when compared to current technology. Increasing speed of computers is a crucial step for many technologies to be able to improve, including but not limited to blockchain, simulations of the outer space, robots, and stock markets.
3. Graphene in Waterproof Electronics – One of the main problems of electronic devices which people are afraid of is being dropped to water. Instead of covering the device with tight-fitted screws, graphene proposes a great solution for this problem. Engineers from Iowa State University print the circuits of the device with graphene flakes because graphene is transparent, strong and conducts electricity. Graphene flakes are arranged in a specific order and non-conductive binders are used to combine them which improved the conductivity. As in the most application areas, graphene again puts a great solution to this problem.
4. Graphene in Wearable Electronics – Researchers are looking for new ways to power wearable devices. One of the outstanding ways is flexible batteries printed on a fabric with graphene. This enables people to wear their batteries and power their smartphones or other devices, literally. If this can be achieved, it will be an environmentally friendly and smart e-textile that can store energy. Carrying heavy power-banks or chargers will be history by the invention of this amazing idea.
5. Graphene for Touchscreens – Indium tin oxide (ITO) is the commercial product used as transparent conductor of the smartphones, tablets, and computers. Researchers from the Rice University have developed a graphene-based thin film to be used in touchscreens. It is found that graphene-based thin film beats ITO and any other materials in terms of performance because it has lower resistance and higher transparency. Thus, Graphene is the new candidate material for the replacement of ITO.
6. Graphene in Flexible Screens – The world of technology would be one of the great beneficiaries of the standardization of graphene as a material to incorporate in products such as smartphones or tablets. It would be the definitive step to advance in the world of smartphones. Recently, a Chinese company has produced a bendable smartphone with a graphene touch screen. Since one layer of graphene is strong, light, transparent and very conductive, it meets all the requirements for the production of smartphones. The smartphone of the Chinese company has the ability to wrap a twist completely, and it weighs only 200 grams which propose a perfect convenience for usage. However, production of graphene is expensive at an industrial scale relative to other materials used in smartphones. Researchers are looking for ways to produce graphene at lower costs. When this problem and some others are solved, old phones seem to be replaced by these flexible smartphones in the future.
7. Graphene in Hard Drives and Memories – Usually, graphene is not considered magnetic, at least not in a controllable or useful way. In 2015, researchers from U.S. Naval Research Laboratory have found a way to turn graphene into a reliable and controllable electromagnetic material. If this innovation is used in hard drives, it is expected to have a capacity almost a million times greater than what we use today.
8. Graphene in Elastic Robots – A team of researchers has developed a gel that is sensitive to near infrared light so that it could be used in numerous applications when creating flexible or elastic robotic parts. The snake-like robots created with this method are able to change its form without any forces from the outside. Their future applications can vary from search-and-rescue to medical operations.
9. Graphene as a Superconductor – Scientists have discovered that graphene can also be used as a superconductive material. Two layers of Graphene can conduct the electron without any resistance. This can be accomplished by twisting these two layers of graphene at a ‘magic angle’ which is 1.1°. Most of the superconductive materials show their properties at temperatures close to absolute zero. Even High temperature superconductive materials relative to usual ones can work at around -140°C. In other words, these superconductive materials require a huge energy for cooling. If graphene can be used as a superconductive material at temperatures close to room temperature, there will be a huge revolution for many application areas.
10. Graphene in Optoelectronics – Researchers are working on a new material for the optical communications since energy and power requirement increase as the time passes. A research conducted by the collaboration of different universities has shown that integrating graphene with silicon can beat current silicon photonic technology. How can it beat the current state of art? Because devices made by graphene are cheaper, simpler and work at high-scale wavelengths. Apparently, graphene will present a low-energy optical telecommunication and many other convenient optical systems.
11. Graphene in Optical Sensors – Graphene has a lot of breakthroughs in industry and science owing to its super properties. Researchers tried to shrink the light to make optical sensors smaller. Recently, the Institute of Photonic Sciences (ICFO) in Barcelona, with the collaboration of Graphene Flagship team, conducted a study which explains the reduction of light down to just a single atom thick which is thought to be impossible by many researchers. This discovery will lead to a huge step in ultra-small optical sensors and switches.
12. Graphene Security Sensors – One of the first practical and real applications of graphene was security labels. Instead of the bulky sensors that many stores use, the sensors made with graphene are smaller, more aesthetic, able to bend without creating a damage on the circuit, and cost only a couple cents per tag.

4. Energy Storage and Thermal Applications

Imagine fully charging a smartphone in seconds, or an electric car in minutes. That’s the power of graphene. Since graphene is the world’s thinnest material, it also extremely high surface-area to volume ratio. This makes graphene a very promising material for use in batteries and supercapacitors. Graphene may enable batteries and supercapacitors (and even fuel-cells) that can store more energy – and charge faster, too.

Graphene is the most heat conductive found to date. As graphene is also strong and light, it means that it is a great material for making heat-spreading solutions, such as heat sinks or heat dissipation films. This could be useful in both microelectronics (for example to make LED lighting more efficient and longer lasting) and also in larger applications – for example thermal foils for mobile devices. Huawei’s latest smartphones, for example, have adopted graphene-based thermal films.

1. Graphene in Solar Cells – The idea of developing lighter, flexible and transparent solar cells has been around for a while but finding the material which has all the properties and able to carry the current was the issue. Indium Tin Oxide has been used because it was transparent, however it was not flexible therefore the cell had to remain stiff.In 2017, researchers from MIT have managed to apply Graphene successfully on a solar cell. When they compared the graphene solar cell with others made of Aluminum and Indium Tin Oxide, they saw that it was as good as the ITO cell, and a little worse than Al one in terms of current densities and power conversion efficiencies. However, it is expected for a transparent cell to perform lower than Aluminum-based, which is nontransparent.Although electrical properties were not a breakthrough, a solar cell that can be installed on any kind of surface (cars, clothes, paper, and cell phones, etc.) which is flexible and transparent was developed. Moreover, other scientists are trying to find out if graphene solar cells can generate energy from raindrops, which theoretically looks possible.
2. Graphene Batteries – Graphene enhanced Li-ion batteries show incredible characteristics such as longer lifespan, higher capacity, and faster charging time as well as flexibility and lightness, so that it could be used in wearable electronics.
3. Graphene in Nuclear Power Plants – Heavy water used in nuclear power plants to cool the reactors is both costly to produce and causes a million tons of CO2 emissions during production. Researchers from University of Manchester have discovered that there is a greener and low-cost method to produce heavy water: graphene membranes. Team leader Dr. Lozada-Hidalgo believes that this innovation is extremely important and its introduction to the nuclear industry will be soon even though this industry is usually skeptical about new technologies.
4. Graphene in Thermoelectric – Seebeck effect is defined as a thermoelectric effect occurring when heat is applied to one of the two dissimilar electric conductors (or semiconductors) to move the electrons from the hot part to the cooler part and produce electricity. However, the energy generated by this method is really small, usually quantified by microvolts. Still, it is believed that it can be used to benefit from the heat generated by the engines, which is practically wasted. Graphene can be used to increase the Seebeck effect created by Strontium Titanate, almost up to 5 times.
5. Graphene in Fuel Cells- Even hydrogen atoms, known as the smallest atom, cannot pass through Graphene. In another research, Sir Andre Geim and his team have tested if protons would be blocked by graphene or not. Suprisingly, protons could pass through graphene. This property would improve fuel cells performance by lowering the fuel crossover which is a major problem with fuel cells that decreases durability and efficiency.

5. Graphene membranes

Imagine clean drinking water for millions in developing countries. The development of graphene-based membranes at The University of Manchester brings that possibility closer. Graphene oxide membranes are capable of forming a perfect barrier when dealing with liquids and gasses. They can effectively separate organic solvent from water and remove water from a gas mixture to an exceptional level. They have even been proved to stop helium, the hardest gas to block.

Potential applications – The simplicity of the technique and the sophistication of the membranes developed at The University of Manchester means the scope for potential applications is widening quickly, while each day of research brings with it new ideas. We are currently looking at how graphene membranes can be used for water filtration, gas separation and desalination projects.

Graphene coatings – A single layer of atoms that can act as a perfect barrier has the potential to open up vast new markets and revolutionise countless industrial processes. Using graphene coatings on food and pharmaceutical packaging can stop the transfer of water and oxygen, keeping food and perishable goods fresher for longer. The removal of harmful carbon dioxide released into the atmosphere by power stations is not currently done on any scale, graphene membranes could change that.

6. Food Industry

1. Graphene in Food Packaging – Graphene can also be used as a coating material because it prevents the transfer of water and oxygen. Graphene membranes can be used in food or pharmaceutical packaging by keeping food and medicines fresh for longer time. It may seem a simple application, but it can dramatically reduce the amount of food waste people throw away every day.
2. Graphene in Water Purification- Normally, water purification is not a simple process and feasibility of the process depends on how heavily the water is contaminated. An Australian scientist has found a low-cost technique to purify water at one step. Soybean-based graphene, which is also called ‘GrapHair’, is used as a filter. This filter can make the dirtiest water drinkable. it is more efficient, cheaper and environmentally friendly compared to other methods.
3. Graphene in Desalination – Approximately, 97.5% of the total water present on the planet is salty. It does not matter how many wells we excavate, only 2.5% of the total is fresh water. The filters based on meshes that use graphene have yielded amazing results. The University of Manchester employed graphene to make filtering sieve that has higher density and permit the water particles to pass but prevents the salts.
4. Graphene in Crop Protection – Graphene is a great material for sensors. Micro-sized sensors can be produced thanks to graphene’s unique structure. It can detect whether a molecule is dangerous or not for the environment. These sensors can be used in food industry, especially in crop protection. Farmers can track and detect dangerous and harmful gasses to crop and they can determine the ideal areas for the growth of the crop depending on the atmospheric conditions, and even the moisture level and “thirst” of the plants with the help of graphene sensors.
5. Graphene for Food Security – Studies done by US Rice University have shown that laser-induced graphene can be applied to various substances such as wood, bread, coconut, etc. It may seem like a substance with a pattern on it printed with ink, but it is not. The laser carburizes the material and carburized material is converted into graphene. Any pattern that is desired can be achieved by this technique. Issues that are related to food security can be overcame by this technique.
6. Graphene in Alcohol Distillation Graphene’s physical properties is so interesting and unique that, it would let large water molecules to pass through but stop Helium molecules which could leak through glass. Andre Geim (one of the inventors of Graphene) and Rahul Nair from Manchester University have tried sealing a bottle of vodka with graphene membrane that they have developed, and discovered that graphene could distill ethanol effectively even at room temperature and without the vacuum needed for distillation methods. This area of utilization can be employed in alcoholic beverages, fuel, water purification and so on.

What is Graphene and How is Graphene Manufactured ?

What is Graphene and Why is it Special?

Graphene is a new material that was first isolated in 2004. It is made up of a single layer of graphite – the same graphite used in pencil lead. Geim and Novoselov first isolated graphene by repeatedly separating graphite fragments with sticky tape until they created one-atom-thick flakes.

Although graphene’s discovery may sound simple, its structure is remarkable. Graphene has a two-dimensional crystalline structure; the atoms’ flat layer consists of hexagonal rings of carbon, which gives a ‘honeycomb’ structure. The layer itself is approximately 0.33 nanometres thick. Before graphene, it was believed that two-dimensional molecules could not exist due to thermal instability.

This structure gives graphene unique properties. Experiments have shown it to be the most robust material now known to us, being at least 200 times stronger than steel due to its strong electrostatic forces and lack of defects. Graphene is also an excellent conductor of heat and electricity thanks to its flat, hexagonal structure, meaning there is little resistance for electrons’ movement.

As well as being extremely strong, graphene is a lightweight material weighing only 0.77 milligrams per square meter. It is also very flexible; research has shown it can be stretched up to 25% of its original length without breaking.

All these properties are remarkable on their own. However, it is the combination of them in one material that has led graphene to be dubbed a wonder material with potential applications in all different types of industries.

What is Graphene Currently Used for?

Graphene’s properties open many doors for it to be used in various applications. Over 15 years since it was first isolated, many graphene products have come to the market and graphene is expanding into new sectors year on year.

One of the markets where graphene first appeared was in applications with low entry barriers, such as sports equipment. Within this industry, the multimillion-dollar company Head has taken advantage of graphene’s strength and flexibility by incorporating it into the frame of a new tennis racket line, Grays has incorporated graphene into their hockey sticks, Vittoria and Goodyear have launched graphene-enhanced bicycle tires, and Standard Graphene in Korea has previously showcased a very lightweight bicycle frame infused with graphene.

Beyond sports equipment, sports clothing was another early adopter of graphene thanks to its thermal regulation and durability in textiles, with Deewear initially leading the way alongside Directa Plus. Inov-8, a sportswear brand, worked with the National Graphene Institute based in Manchester, UK, to release the company’s first graphene-enhanced running shoe in 2018, eventually expanding into a full range. Inov-8 states that the graphene-enhanced rubber is 50% stronger and 50% more elastic than regular rubber.

Beyond the sports industry, companies such as Graphene-X have been taking to Kickstarter to launch everyday-use graphene-enhanced jackets and pants with great success.

One area where graphene has been trialed a lot is in coatings, with both electronically conductive coatings (for printable circuits) and barrier coatings being developed, a lot of which have found use for protecting the hulls of ships.

The main ones are as follows:

1. Mechanical peeling method

advantages:

the preparation cost is very low (almost negligible), easy to learn, and the graphene obtained by this method is very good in quality, has few defects, and has excellent performance.

Disadvantage:

the size of graphene obtained Very small, generally between 10-100um, and it is completely impossible to prepare on a large scale.

2. SiC epitaxial growth

Advantages:

can grow in larger sizes (reported by 4 inches), and the performance of the obtained graphene is excellent.

Disadvantage:

High cost, high equipment cost, high growth temperature (1400°), general equipment is not available, and it is difficult to grow graphene of too large size.

3. graphite oxide reduction method:

advantages:

simple method, raw material cost Not high, basically no equipment cost, and easy to scale preparation

Disadvantages:

This method has a lot of graphene defects, electrical and mechanical properties are poor

4. CVD, chemical vapor deposition method

advantages:

single growth size can be very large (near 20 inches), it is possible to scale production, and the graphene produced by the performance is very good.

Disadvantages: :

the transfer is a problem, and the growth is generally polycrystalline.

The most common idea for preparing graphene is to first oxidize the graphite, and then use graphite, high temperature, etc. to peel off the graphite layer by layer (of course, maybe several layers) and finally reduce it.

There are no mass productions in the industry this year, and a small amount of preparations can be seen in the laboratories of enterprises, research institutes or universities. Let me talk about how to get graphite oxide.

There are three ways: Hummers, Brodie, and Staudenmaier.

After the experiment, everyone found that the most convenient and most suitable is the Hummers method, so the other two methods will not be said. Hummers method: use 23 mL of concentrated sulfuric acid, 4 g of potassium permanganate and 1 g of graphite to mix uniformly, react at 40 ° C for 30 minutes, then dilute, add 5 mL of 30% hydrogen peroxide to remove potassium permanganate, wash with 250 mL of 10% diluted hydrochloric acid, and finally not Drying blasting above 30 degrees Celsius yields a yellow graphite oxide solid.

This is followed by stripping of the graphite oxide. The graphite oxide is ground into a powder and rapidly heated to 500 degrees under microwave irradiation. Or take 0.02% solution of graphite oxide and put it in 150W ultrasonic for 15min, and then carry out reduction reaction with hydrazine hydrate (mass ratio of graphite oxide to 7:10) at 85 degrees to obtain single or multi-layer graphene dispersion. . said that tearing down the tape for half a month to get a dozen layers is too exaggerated, in fact, you can do it in 5 minutes, listen to me decomposition.

Assume that each time you tear, the graphite on each side of the tape is half, and the graphite has one million layers. Then after repeating the operation of “sticking and tearing” 20 times, it is a million squares divided by 2 (2 The 20th power is equal to 1000000), which is about equal to one floor.

That is to say, you can divide a million layers of graphite into one layer by repeatedly tearing it 20 times.

The graphene obtained by this method is easily attached to the tape by a layer, and it is easy to observe and test with experimental equipment. Finally, this new material was discovered in 2004 and won the 2010 Nobel Prize in Physics.

What is graphene and what is it used for?

Graphene is a crystalline allotrope of carbon with 2-dimensional properties. Its carbon atoms are densely packed in a regular atomic-scale chicken wire (hexagonal) pattern. Each atom has four bonds, one σ bond with each of its three neighbors and one π-bond that is oriented out of plane. The atoms are about 1.42 Å apart.

Graphene’s hexagonal lattice can be regarded as two interleaving triangular lattices. This perspective was successfully used to calculate the band structure for a single graphite layer using a tight-binding approximation。Graphene is amazing. Or at least, it could be. Made from a layer of carbon one-atom thick, it’s the strongest material in the world, it’s completely flexible, and it’s more conductive than copper. Discovered just under a decade ago, the supermaterial potentially has some unbelievable applications for us in the not so distant future.

Graphene, the well-publicised and now famous two-dimensional carbon allotrope, is as versatile a material as any discovered on Earth. Its amazing properties as the lightest and strongest material, compared with its ability to conduct heat and electricity better than anything else, mean that it can be integrated into a huge number of applications. Initially this will mean that graphene is used to help improve the performance and efficiency of current materials and substances, but in the future it will also be developed in conjunction with other two-dimensional (2D) crystals to create some even more amazing compounds to suit an even wider range of applications. To understand the potential applications of graphene, you must first gain an understanding of the basic properties of the material.

The first time graphene was artificially produced; scientists literally took a piece of graphite and dissected it layer by layer until only 1 single layer remained. This process is known as mechanical exfoliation. This resulting monolayer of graphite (known as graphene) is only 1 atom thick and is therefore the thinnest material possible to be created without becoming unstable when being open to the elements (temperature, air, etc.). Because graphene is only 1 atom thick, it is possible to create other materials by interjecting the graphene layers with other compounds (for example, one layer of graphene, one layer of another compound, followed by another layer of graphene, and so on), effectively using graphene as atomic scaffolding from which other materials are engineered. These newly created compounds could also be superlative materials, just like graphene, but with potentially even more applications.

After the development of graphene and the discovery of its exceptional properties, not surprisingly interest in other two-dimensional crystals increased substantially. These other 2D crystals (such as Boron Nitride, Niobium Diselenide and Tantalum (IV) sulphide), can be used in combination with other 2D crystals for an almost limitless number of applications. So, as an example, if you take the compound Magnesium Diboride (MgB2), which is known as being a relatively efficient superconductor, then intersperse its alternating boron and magnesium atomic layers with individual layers of graphene, it improves its efficiency as a superconductor. Or, another example would be in the case of combining the mineral Molybdenite (MoS2), which can be used as a semiconductor, with graphene layers (graphene being a fantastic conductor of electricity) when creating NAND flash memory, to develop flash memory to be much smaller and more flexible than current technology, (as has been proven by a team of researchers at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland).

The only problem with graphene is that high-quality graphene is a great conductor that does not have a band gap (it can’t be switched off). Therefore to use graphene in the creation of future nano-electronic devices, a band gap will need to be engineered into it, which will, in turn, reduce its electron mobility to that of levels currently seen in strained silicon films. This essentially means that future research and development needs to be carried out in order for graphene to replace silicon in electrical systems in the future. However, recently a few research teams have shown that not only is this possible, it is probable, and we are looking at months, rather than years, until this is achieved at least at a basic level. Some say that these kinds of studies should be avoided, though, as it is akin to changing graphene to be something it is not.

In any case, these two examples are just the tip of the iceberg in only one field of research, whereas graphene is a material that can be utilized in numerous disciplines including, but not limited to: bioengineering, composite materials, energy technology and nanotechnology.

Mechanical strength

Graphene is the world’s strongest material, and so can be used to enhance the strength of other materials. Dozens of researches have demonstrated that adding even a trade amount of graphene to plastics, metals or other materials can make these materials much stronger – or lighter (as you can use less amount of material to achieve the same strength).

Thermal applications

Graphene is the world’s most conductive material to heat. As graphene is also strong and light, it means that it is a great material to make heat-spreading solutions, such as heat sinks. This could be useful in both microelectronics (for example to make LED lighting more efficient and longer lasting) and also in larger applications – for example thermal foils for mobile devices.

Biological Engineering

Bioengineering will certainly be a field in which graphene will become a vital part of in the future; though some obstacles need to be overcome before it can be used. Current estimations suggest that it will not be until 2030 when we will begin to see graphene widely used in biological applications as we still need to understand its biocompatibility (and it must undergo numerous safety, clinical and regulatory trials which, simply put, will take a very long time). However, the properties that it displays suggest that it could revolutionise this area in a number of ways. With graphene offering a large surface area, high electrical conductivity, thinness and strength, it would make a good candidate for the development of fast and efficient bioelectric sensory devices, with the ability to monitor such things as glucose levels, haemoglobin levels, cholesterol and even DNA sequencing. Eventually we may even see engineered ‘toxic’ graphene that is able to be used as an antibiotic or even anticancer treatment. Also, due to its molecular make-up and potential biocompatibility, it could be utilised in the process of tissue regeneration.

Optical Electronics

One particular area in which we will soon begin to see graphene used on a commercial scale is that in optoelectronics; specifically touchscreens, liquid crystal displays (LCD) and organic light emitting diodes (OLEDs). For a material to be able to be used in optoelectronic applications, it must be able to transmit more than 90% of light and also offer electrical conductive properties exceeding 1 x 106 Ω1m1 and therefore low electrical resistance. Graphene is an almost completely transparent material and is able to optically transmit up to 97.7% of light. It is also highly conductive, as we have previously mentioned and so it would work very well in optoelectronic applications such as LCD touchscreens for smartphones, tablet and desktop computers and televisions.

Currently the most widely used material is indium tin oxide (ITO), and the development of manufacture of ITO over the last few decades time has resulted in a material that is able to perform very well in this application. However, recent tests have shown that graphene is potentially able to match the properties of ITO, even in current (relatively under-developed) states. Also, it has recently been shown that the optical absorption of graphene can be changed by adjusting the Fermi level. While this does not sound like much of an improvement over ITO, graphene displays additional properties which can enable very clever technology to be developed in optoelectronics by replacing the ITO with graphene. The fact that high quality graphene has a very high tensile strength, and is flexible (with a bending radius of less than the required 5-10mm for rollable e-paper), makes it almost inevitable that it will soon become utilized in these aforementioned applications.

In terms of potential real-world electronic applications we can eventually expect to see such devices as graphene based e-paper with the ability to display interactive and updatable information and flexible electronic devices including portable computers and televisions.

Coatings ,sensors, electronics and more

Graphene has a lot of other promising applications: anti-corrosion coatings and paints, efficient and precise sensors, faster and efficient electronics, flexible displays, efficient solar panels, faster DNA sequencing, drug delivery, and more.

Graphene is such a great and basic building block that it seems that any industry can benefit from this new material. Time will tell where graphene will indeed make an impact – or whether other new materials will be more suitable.

Ultrafiltration

Another standout property of graphene is that while it allows water to pass through it, it is almost completely impervious to liquids and gases (even relatively small helium molecules). This means that graphene could be used as an ultrafiltration medium to act as a barrier between two substances. The benefit of using graphene is that it is only 1 single atom thick and can also be developed as a barrier that electronically measures strain and pressures between the 2 substances (amongst many other variables). A team of researchers at Columbia University have managed to create monolayer graphene filters with pore sizes as small as 5nm (currently, advanced nanoporous membranes have pore sizes of 30-40nm). While these pore sizes are extremely small, as graphene is so thin, pressure during ultrafiltration is reduced. Co-currently, graphene is much stronger and less brittle than aluminium oxide (currently used in sub-100nm filtration applications). What does this mean? Well, it could mean that graphene is developed to be used in water filtration systems, desalination systems and efficient and economically more viable biofuel creation.

Composite Materials

Graphene is strong, stiff and very light. Currently, aerospace engineers are incorporating carbon fibre into the production of aircraft as it is also very strong and light. However, graphene is much stronger whilst being also much lighter. Ultimately it is expected that graphene is utilized (probably integrated into plastics such as epoxy) to create a material that can replace steel in the structure of aircraft, improving fuel efficiency, range and reducing weight. Due to its electrical conductivity, it could even be used to coat aircraft surface material to prevent electrical damage resulting from lightning strikes. In this example, the same graphene coating could also be used to measure strain rate, notifying the pilot of any changes in the stress levels that the aircraft wings are under. These characteristics can also help in the development of high strength requirement applications such as body armour for military personnel and vehicles.

Photovoltaic Cells

Offering very low levels of light absorption (at around 2.7% of white light) whilst also offering high electron mobility means that graphene can be used as an alternative to silicon or ITO in the manufacture of photovoltaic cells. Silicon is currently widely used in the production of photovoltaic cells, but while silicon cells are very expensive to produce, graphene based cells are potentially much less so. When materials such as silicon turn light into electricity it produces a photon for every electron produced, meaning that a lot of potential energy is lost as heat. Recently published research has proved that when graphene absorbs a photon, it actually generates multiple electrons. Also, while silicon is able to generate electricity from certain wavelength bands of light, graphene is able to work on all wavelengths, meaning that graphene has the potential to be as efficient as, if not more efficient than silicon, ITO or (also widely used) gallium arsenide. Being flexible and thin means that graphene based photovoltaic cells could be used in clothing; to help recharge your mobile phone, or even used as retro-fitted photovoltaic window screens or curtains to help power your home.

Energy Storage

Because graphene is the world’s thinnest material, it is also the material with the highest surface-area to volume ratio. This makes graphene a very promising material to be used in batteries and supercapacitors. Graphene may enable devices that can store more energy – and charge faster, too. Graphene can also be used to enhance fuel-cells. While all areas of electronics have been advancing over a very fast rate over the last few decades (in reference to Moore’s law which states that the number of transistors used in electronic circuitry will double every 2 years), the problem has always been storing the energy in batteries and capacitors when it is not being used. These energy storage solutions have been developing at a much slower rate. The problem is this: a battery can potentially hold a lot of energy, but it can take a long time to charge, a capacitor, on the other hand, can be charged very quickly, but can’t hold that much energy (comparatively speaking). The solution is to develop energy storage components such as either a supercapacitor or a battery that is able to provide both of these positive characteristics without compromise.

Currently, scientists are working on enhancing the capabilities of lithium ion batteries (by incorporating graphene as an anode) to offer much higher storage capacities with much better longevity and charge rate. Also, graphene is being studied and developed to be used in the manufacture of supercapacitors which are able to be charged very quickly, yet also be able to store a large amount of electricity. Graphene based micro-supercapacitors will likely be developed for use in low energy applications such as smart phones and portable computing devices and could potentially be commercially available within the next 5-10 years. Graphene-enhanced lithium ion batteries could be used in much higher energy usage applications such as electrically powered vehicles, or they can be used as lithium ion batteries are now, in smartphones, laptops and tablet PCs but at significantly lower levels of size and weight.

What is the Properties of Graphene ?

Graphene is an allotrope (form) of carbon consisting of a single layer of carbon atoms arranged in an hexagonal lattice. It is the basic structural element of many other allotropes of carbon, such as graphite, charcoal, carbon nanotubes and fullerenes. Graphene is, basically, a single atomic layer of graphite; an abundant mineral which is an allotrope of carbon that is made up of very tightly bonded carbon atoms organised into a hexagonal lattice. What makes graphene so special is its sp² hybridisation and very thin atomic thickness (of 0.345Nm).

These properties are what enable graphene to break so many records in terms of strength, electricity and heat conduction (as well as many others). Now, let’s explore just what makes graphene so special, what are its intrinsic properties that separate it from other forms of carbon, and other 2D crystalline compounds?

FUNDAMENTAL CHARACTERISTICS

Before monolayer graphene was isolated in 2004, it was theoretically believed that two dimensional compounds could not exist due to thermal instability when separated. However, once graphene was isolated, it was clear that it was actually possible, and it took scientists some time to find out exactly how. After suspended graphene sheets were studied by transmission electron microscopy, scientists believed that they found the reason to be due to slight rippling in the graphene, modifying the structure of the material. However, later research suggests that it is actually due to the fact that the carbon to carbon bonds in graphene are so small and strong that they prevent thermal fluctuations from destabilizing it.

ELECTRONIC PROPERTIES

Graphene is a zero-gap semiconductor, because its conduction and valence bands meet at the Dirac points, which are six locations in momentum space, on the edge of the Brillouin zone, divided into two non-equivalent sets of three points. One of the most useful properties of graphene is that it is a zero-overlap semimetal (with both holes and electrons as charge carriers) with very high electrical conductivity. Carbon atoms have a total of 6 electrons; 2 in the inner shell and 4 in the outer shell. The 4 outer shell electrons in an individual carbon atom are available for chemical bonding, but in graphene, each atom is connected to 3 other carbon atoms on the two dimensional plane, leaving 1 electron freely available in the third dimension for electronic conduction. These highly-mobile electrons are called pi (π) electrons and are located above and below the graphene sheet. These pi orbitals overlap and help to enhance the carbon to carbon bonds in graphene. Fundamentally, the electronic properties of graphene are dictated by the bonding and anti-bonding (the valance and conduction bands) of these pi orbitals.

Combined research over the last 50 years has proved that at the Dirac point in graphene, electrons and holes have zero effective mass. This occurs because the energy – movement relation (the spectrum for excitations) is linear for low energies near the 6 individual corners of the Brillouin zone. These electrons and holes are known as Dirac fermions, or Graphinos, and the 6 corners of the Brillouin zone are known as the Dirac points. Due to the zero density of states at the Dirac points, electronic conductivity is actually quite low. However, the Fermi level can be changed by doping (with electrons or holes) to create a material that is potentially better at conducting electricity than, for example, copper at room temperature.

Tests have shown that the electronic mobility of graphene is very high, with previously reported results above 15,000 cm2·V−1·s−1 and theoretically potential limits of 200,000 cm2·V−1·s−1 (limited by the scattering of graphene’s acoustic photons). It is said that graphene electrons act very much like photons in their mobility due to their lack of mass. These charge carriers are able to travel sub-micrometer distances without scattering; a phenomenon known as ballistic transport. However, the quality of the graphene and the substrate that is used will be the limiting factors. With silicon dioxide as the substrate, for example, mobility is potentially limited to 40,000 cm2·V−1·s−1.

“In terms of how far along we are to understanding the true properties of graphene, this is just the tip of iceberg. Before graphene is heavily integrated into the areas in which we believe it will excel at, we need to spend a lot more time understanding just what makes it such an amazing material”

MECHANICAL STRENGTH

Another of graphene’s stand-out properties is its inherent strength. Due to the strength of its 0.142 Nm-long carbon bonds, graphene is the strongest material ever discovered, with an ultimate tensile strength of 130,000,000,000 Pascals (or 130 gigapascals), compared to 400,000,000 for A36 structural steel, or 375,700,000 for Aramid (Kevlar). Not only is graphene extraordinarily strong, it is also very light at 0.77milligrams per square metre (for comparison purposes, 1 square metre of paper is roughly 1000 times heavier). It is often said that a single sheet of graphene (being only 1 atom thick), sufficient in size enough to cover a whole football field, would weigh under 1 single gram.

What makes this particularly special is that graphene also contains elastic properties, being able to retain its initial size after strain. In 2007, Atomic force microscopic (AFM) tests were carried out on graphene sheets that were suspended over silicone dioxide cavities. These tests showed that graphene sheets (with thicknesses of between 2 and 8 Nm) had spring constants in the region of 1-5 N/m and a Young’s modulus (different to that of three-dimensional graphite) of 0.5 TPa. Again, these superlative figures are based on theoretical prospects using graphene that is unflawed containing no imperfections whatsoever and currently very expensive and difficult to artificially reproduce, though production techniques are steadily improving, ultimately reducing costs and complexity.

OPTICAL PROPERTIES

Graphene’s ability to absorb a rather large 2.3% of white light is also a unique and interesting property, especially considering that it is only 1 atom thick. This is due to its aforementioned electronic properties; the electrons acting like massless charge carriers with very high mobility. A few years ago, it was proved that the amount of white light absorbed is based on the Fine Structure Constant, rather than being dictated by material specifics. Adding another layer of graphene increases the amount of white light absorbed by approximately the same value (2.3%). Graphene’s opacity of πα ≈ 2.3% equates to a universal dynamic conductivity value of G=e2/4ℏ (±2-3%) over the visible frequency range.

Due to these impressive characteristics, it has been observed that once optical intensity reaches a certain threshold (known as the saturation fluence) saturable absorption takes place (very high intensity light causes a reduction in absorption). This is an important characteristic with regards to the mode-locking of fibre lasers. Due to graphene’s properties of wavelength-insensitive ultrafast saturable absorption, full-band mode locking has been achieved using an erbium-doped dissipative soliton fibre laser capable of obtaining wavelength tuning as large as 30 nm.

In terms of how far along we are to understanding the true properties of graphene, this is just the tip of the iceberg. Before graphene is heavily integrated into the areas in which we believe it will excel at, we need to spend a lot more time understanding just what makes it such an amazing material. Unfortunately, while we have a lot of imagination in coming up with new ideas for potential applications and uses for graphene, it takes time to fully appreciate how and what graphene really is in order to develop these ideas into reality. This is not necessarily a bad thing, however, as it gives us opportunities to stumble over other previously under-researched or overlooked super-materials, such as the family of 2D crystalline structures that graphene has born.

What is Graphene ?

Graphene is an allotrope (form) of carbon consisting of a single layer of carbon atoms arranged in an hexagonal lattice. It is the basic structural element of many other allotropes of carbon, such as graphite, charcoal, carbon nanotubes and fullerenes.

Graphene and its band structure and Dirac cones, effect of a grid on doping

Graphene can be considered as an indefinitely large aromatic molecule, the ultimate case of the family of flat polycyclic aromatic hydrocarbons. Graphene has many unusual properties. It is the strongest material ever tested, efficiently conducts heat and electricity and is nearly transparent. Graphene shows a large and nonlinear diamagnetism, which is greater than that of graphite, and can be levitated by neodymium magnets.

Scientists theorized about graphene for years. It had been unintentionally produced in small quantities for centuries, through the use of pencils and other similar graphite applications. It was originally observed in electron microscopes in 1962, but it was studied only while supported on metal surfaces.

The material was later rediscovered, isolated, and characterized in 2004 by Andre Geim and Konstantin Novoselov at the University of Manchester. Research was informed by existing theoretical descriptions of its composition, structure, and properties. This work resulted in the two winning the Nobel Prize in Physics in 2010 “for groundbreaking experiments regarding the two-dimensional material graphene.”

“Graphene” is a combination of “graphite” and the suffix -ene, named by Hanns-Peter Boehm, who described single-layer carbon foils in 1962.

Graphene is an atomic-scale hexagonal lattice made of carbon atoms.

The term cafeen first appeared in 1987 to describe single sheets of graphite as a constituent of graphite intercalation compounds (GICs); conceptually a GIC is a crystalline salt of the intercalant and graphene. The term was also used in early descriptions of carbon nanotubes, as well as for epitaxial graphene and polycyclic aromatic hydrocarbons (PAH).

Graphene can be considered an “infinite alternant” (only six-member carbon ring) polycyclic aromatic hydrocarbon.

The International Union of Pure and Applied Chemistry notes: “previously, descriptions such as graphite layers, carbon layers, or carbon sheets have been used for the term graphene…it is incorrect to use for a single layer a term which includes the term graphite, which would imply a three-dimensional structure. The term graphene should be used only when the reactions, structural relations or other properties of individual layers are discussed.”

Geim defined “isolated or free-standing graphene” as “graphene is a single atomic plane of graphite, which – and this is essential – is sufficiently isolated from its environment to be considered free-standing.” This definition is narrower than the IUPAC definition and refers to cloven, transferred and suspended graphene. Other forms such as graphene grown on various metals, can become free-standing if, for example, suspended or transferred to silicon dioxide (SiO2) or silicon carbide.

The theory of graphene was first explored by Wallace in 1947 as a starting point for understanding the electronic properties of 3D graphite. The emergent massless Dirac equation was first pointed out by Semenoff, DiVincenzo and Mele. The earliest TEM images of few-layer graphite were published by Ruess and Vogt in 1948.

A lump of graphite, a graphene transistor, and a tape dispenser. Donated to the Nobel Museum in Stockholm by Andre Geim and Konstantin Novoselov in 2010.

An early, detailed study on few-layer graphite dates to 1962 when Boehm reported producing monolayer flakes of reduced graphene oxide. Efforts to make thin films of graphite by mechanical exfoliation started in 1990, but nothing thinner than 50 to 100 layers was produced before 2004. Initial attempts to make atomically thin graphitic films employed exfoliation techniques similar to the drawing method. Multilayer samples down to 10 nm in thickness were obtained.

One of the first patents pertaining to the production of graphene was filed in October 2002 and granted in 2006. Two years later, in 2004 Geim and Novoselov extracted single-atom-thick crystallites from bulk graphite and transferred them onto thin silicon dioxide (SiO2) on a silicon wafer,which electrically isolated the graphene.

The cleavage technique led directly to the first observation of the anomalous quantum Hall effect in graphene, which provided direct evidence of graphene’s theoretically predicted Berry’s phase of massless Dirac fermions. The effect was reported by Geim’s group and by Kim and Zhang, whose papers appeared in Nature in 2005. Geim and Novoselov received awards for their pioneering research on graphene, notably the 2010 Nobel Prize in Physics.

Commercialization of graphene proceeded rapidly once commercial scale production was demonstrated. By 2017, 13 years after creation of the first laboratory graphene electronic device, an integrated graphene electronics chip was produced commercially and marketed to pharmaceutical researchers by Nanomedical Diagnostics in San Diego.