Nobel Prize in Physics 2010: Graphene and the Two-Dimensional Carbon Breakthrough

This note covers the Nobel Prize in Physics 2010: who won it, what graphene is and why isolating a single layer of carbon surprised physicists, how Andre Geim and Konstantin Novoselov pulled it off with sticky tape and a pencil, what makes graphene's electrons behave so strangely, how the discovery unfolded, why it matters for future technology, and quick facts for exams.

What was the Nobel Prize in Physics 2010 awarded for?

The Nobel Prize in Physics 2010 was given jointly to Andre Geim and Konstantin Novoselov "for groundbreaking experiments regarding the two-dimensional material graphene". That is the official citation from the Nobel Prize data service, and it should be read carefully because every word matters.

In plain language, the two scientists found a practical way to isolate and study graphene, a sheet of carbon atoms arranged in a honeycomb pattern that is only one atom thick.

Such a material is called two-dimensional because atoms are added along its length and width but not stacked up in height.

Before 2004, many physicists doubted that a crystal this thin could even exist on its own without curling up or falling apart.

The full official name of this award is the Nobel Prize in Physics, awarded each year by the Royal Swedish Academy of Sciences. The 2010 prize was announced on 5 October 2010, and the laureates shared a prize amount of 10,000,000 Swedish kronor equally between them.

Who are the laureates?

Both laureates worked at the same institution when the prize was announced, and both had earlier trained in Russia before moving west. Each received one half of the prize.

Andre Geim

Andre Geim was born on 21 October 1958 in Sochi, Russia. At the time of the award he was affiliated with the University of Manchester in the United Kingdom, where he held the position of Langworthy Professor of Physics.

He received one half of the prize. Geim had earlier worked in the Netherlands before moving to Manchester, and the Nobel press release notes that he first studied and began his career as a physicist in Russia.

His contribution was leading, with Novoselov, the experiments that isolated graphene and measured its electrical behaviour for the first time.

Konstantin Novoselov

Konstantin Novoselov was born on 23 August 1974 in Nizhny Tagil, Russia. He too was affiliated with the University of Manchester at the time of the award and received one half of the prize.

According to the press release, Novoselov first worked with Geim as a PhD student in the Netherlands and then followed him to the United Kingdom.

He was a central partner in developing the tape-based method that produced the first graphene flakes and in carrying out the measurements that revealed its unusual electronic properties.

What problem were they trying to solve?

Carbon is one of the most important elements, forming the basis of all known life.

It exists in several solid forms: graphite (the soft, stacked material found in pencils), diamond (formed under high pressure), and more exotic forms such as fullerenes (football-shaped carbon cages, honoured by the 1996 Nobel Prize in Chemistry) and carbon nanotubes (rolled-up cylinders of carbon sheets).

Graphite itself is made of many single-atom-thick layers of carbon stacked on top of each other, each held to its neighbours only weakly. One millimetre of graphite contains about three million such layers, so splitting one off requires overcoming only a fairly weak bond between layers rather than breaking a strong chemical bond within a layer.

In theory, a single one of these layers, called graphene, should be an entirely new two-dimensional material with its own electrical and mechanical behaviour.

The Scientific Background paper explains that graphene had been studied theoretically as early as 1947, when physicist P. R. Wallace used it as a textbook calculation in solid state physics and predicted some of its electronic structure. The wave equation describing how particles move inside graphene was later written down by J. W. McClure in 1956, and its resemblance to a famous equation from particle physics was pointed out by G. W. Semenoff in 1984.

The difficulty was not imagining graphene but actually producing and identifying a single free-standing layer.

Many scientists believed such an ultra-thin sheet would simply curl up, crumple or vanish at room temperature, since thin two-dimensional crystals were thought to be unstable.

Earlier attempts using chemical separation or scratching away graphite layers had managed to produce films less than 100 atoms thick, but never a confirmed single layer that could also be electrically tested. Other groups tried burning silicon away from silicon carbide crystals at very high temperature to leave a thin carbon film behind, and a group at Columbia University dragged a graphite crystal across a surface using the tip of a microscope, producing layers down to about ten atoms thick.

The challenge, then, was both to isolate a genuinely single-atom sheet and to find a reliable way of spotting it among much thicker flakes of leftover graphite.

How did Geim and Novoselov actually make graphene?

The method the two scientists used was strikingly simple, built from everyday materials rather than expensive laboratory equipment.

Geim and Novoselov took a piece of ordinary graphite, the kind found in pencils, and used regular adhesive tape to peel thin flakes away from it.

Each time they pressed the tape against the flake and peeled it again, the flakes grew thinner and thinner, a technique often called mechanical exfoliation.

Their key insight was not just the peeling itself but how to find the thinnest flakes once they had them. They had to separate the fragments that were truly one atom thick from thicker, uninteresting scraps.

1. Start with a bulk piece of graphite, which contains millions of stacked graphene layers.
2. Repeatedly press adhesive tape onto the graphite and peel it away, splitting the stack into progressively thinner flakes.
3. Transfer the flakes onto a plate of oxidised silicon, the standard material used in the semiconductor industry.
4. Examine the plate under an ordinary optical microscope, where different flake thicknesses show up as different colours, similar to the rainbow pattern seen when oil spreads on water.
5. Pick out the fragments that show the specific colour corresponding to a single atomic layer, confirming that true graphene has been found.
6. Pattern the chosen flakes and attach electrodes to measure their electrical properties directly.

This optical trick of using a silicon dioxide layer of carefully chosen thickness was what let the Manchester group succeed where an earlier attempt by another research group, using the same tape idea, had failed to identify any single-layer samples.

Draw a thick stack of hexagonal carbon sheets labelled "graphite", an arrow showing tape peeling off thinner and thinner layers, and a single isolated hexagonal honeycomb sheet labelled "graphene, one atom thick" placed on a flat rectangle labelled "silicon plate".

Why does graphene behave so strangely?

Once Geim and Novoselov could reliably produce and test graphene, they discovered properties that made physicists sit up. The Scientific Background document explains two features as especially remarkable.

First, the lattice is almost perfectly ordered. Carbon atoms bond strongly to their three neighbours in the honeycomb pattern, so the structure has very few defects.

This strong but flexible bonding lets the sheet stretch to about one-fifth beyond its original size before breaking, and lets electrons travel long distances through the lattice without the scattering collisions that slow down electrons in ordinary conductors. In a normal conductor, electrons repeatedly bounce off impurities and vibrating atoms, much like a ball ricocheting inside a pinball machine, and each collision wastes energy and slows the current.

Second, electrons in graphene behave as if they have no mass, moving at a constant speed of about one million metres per second, described by equations resembling those used for massless particles such as photons, which travel through a vacuum at roughly 300 million metres per second.

This unusual behaviour let physicists observe quantum effects that are normally only discussed theoretically, such as a variant of Klein tunnelling, a phenomenon predicted by the Swedish physicist Oskar Klein in 1929, in which particles pass through an energy barrier that should normally block them. The idea that graphene could be used to test this effect was first suggested in 2006 and was experimentally confirmed by other physicists in 2009.

Graphene also turned out to be mechanically and thermally exceptional. The press release states it conducts electricity as well as copper, conducts heat better than any other known material, and is almost completely transparent while being so dense that even helium, the smallest gas atom, cannot pass through it. The Scientific Background paper adds that graphene absorbs only about 2.3% of light that passes through it, a figure set by a constant from fundamental physics called the fine structure constant.

How did the discovery unfold?

The route from a theoretical curiosity to a Nobel Prize took place over several decades, with the decisive breakthrough coming in a few short years after 2004.

Why does graphene matter?

The committee's press release and popular information document describe a wide range of possible uses that followed from this discovery, while noting that most were, at the time, no more than ideas, with many already being tested by researchers including Geim and Novoselov themselves.

Because graphene conducts electricity so well and is almost transparent, it was seen as promising for transparent touch screens, light panels and possibly solar cells, where it could one day replace the more fragile and costly material currently used for transparent electrodes.

Mixing a small amount of graphene into plastics was shown to make them conduct electricity while also increasing their heat resistance and mechanical strength, opening the door to lightweight composite materials that could one day be used in satellites, aircraft and cars. The popular information document notes that mixing in only a small fraction of graphene could raise the heat resistance of a plastic by about 30°C while also making it more mechanically robust.

Graphene was also expected to enable faster electronic transistors than those built from silicon, since silicon components run into physical size limits that graphene's thinner structure might avoid, potentially leading to faster and more energy-efficient computers. The sources note that one milestone had already been reached when a graphene transistor as fast as its silicon counterpart was demonstrated, though fully graphene-based computers remained a distant prospect.

The extremely regular structure of graphene additionally made it attractive for building very sensitive sensors, capable of detecting even a single molecule landing on its surface, which could be useful for monitoring pollution. The Scientific Background paper also mentions that the unusual quantum Hall effect seen in graphene might one day help create a more accurate standard for measuring electrical resistance.

At the same time, the sources are careful to note this was an emerging research field.

The popular information document calls many applications "dream worlds" still requiring "significant initiatives with their outcomes still being uncertain", meaning scientists expected further years of work before graphene's full potential, if any, could be realised commercially.

How does this connect to what you study?

Graphene links directly to basic chemistry and physics taught in school. It is built from carbon atoms arranged in a hexagonal, honeycomb pattern, the same bonding idea used to introduce covalent bonds and crystal lattices in chemistry lessons on the structure of solids.

The sources describe carbon as the element forming the basis of all known life, and graphene as one of several solid forms that element can take, alongside graphite, diamond, fullerenes and carbon nanotubes. Comparing these forms is a useful way to revise the topic of allotropes, where the same element behaves very differently depending only on how its atoms are arranged.

Graphene's description as a two-dimensional material, one where atoms extend in length and width but never in height, connects to lessons on dimensions and states of matter, since it sits conceptually between a single molecule and a bulk three-dimensional crystal.

Its unusual electron behaviour gives students an accessible, real example of ideas normally kept abstract in physics class. The Scientific Background paper explains that graphene's electrons behave as if they have no mass and move at a constant speed, governed by equations resembling those for massless particles, which let physicists test effects such as Klein tunnelling in an actual laboratory sample rather than only in theory.

Finally, the press release's comparisons of graphene's electrical and thermal conductivity against copper and silver give a concrete, numbers-based example for lessons on how materials conduct electricity and heat, and why engineers care about those differences when choosing materials for electronics.

What kind of scientists were Geim and Novoselov?

The press release and popular information document describe the two laureates as having a notably playful approach to research, which they credit as part of how the discovery came about.

According to the sources, the two had worked together for a long time before the 2010 prize. Novoselov first worked with Geim as a PhD student in the Netherlands and then followed him to the United Kingdom, and both originally studied and began their careers as physicists in Russia before becoming professors together at the University of Manchester.

The popular information document notes that the pair liked to experiment with the materials at their disposal, sometimes simply by letting ideas develop without a fixed plan, and states that this approach had already produced an unexpected result some years earlier, around 2003: a sticky tape inspired by the way a gecko lizard clings to smooth surfaces.

Andre Geim's playful streak went back further still. In 1997, he managed to make a frog levitate inside a magnetic field, a demonstration of basic physics principles that later earned him the Ig Nobel Prize in 2000, an award intended, in the words of the popular information document, to "make people laugh first and think second".

The same document suggests that this willingness to experiment and follow curiosity, rather than a fixed research plan, was part of how they came to isolate graphene using nothing more sophisticated than graphite and adhesive tape.

Quick facts for exams

The Nobel Prize in Physics 2010 was awarded jointly to Andre Geim and Konstantin Novoselov, both of the University of Manchester, United Kingdom, "for groundbreaking experiments regarding the two-dimensional material graphene". The prize was announced on 5 October 2010 by the Royal Swedish Academy of Sciences, with a total prize amount of 10,000,000 Swedish kronor shared equally between the two laureates. Geim, born in Sochi, Russia in 1958, and Novoselov, born in Nizhny Tagil, Russia in 1974, had earlier trained together in the Netherlands before moving to Manchester. Their breakthrough was isolating graphene, a single-atom-thick sheet of carbon, using adhesive tape peeled from graphite, and then measuring its exceptional electrical, thermal and mechanical properties.

Note: Source. The prize facts in this note are from the Nobel Prize's official site, nobelprize.org.

Glossary

• Graphene — a single layer of carbon atoms arranged in a hexagonal, honeycomb-shaped lattice, one atom thick.
• Two-dimensional material — a crystal in which atoms extend in length and width but not in height.
• Graphite — the common form of carbon found in pencils, made of many stacked graphene layers held together weakly.
• Mechanical exfoliation — peeling thin layers off a bulk crystal, in this case using adhesive tape on graphite.
• Fullerene — a football-shaped cage molecule of carbon atoms, honoured by the 1996 Nobel Prize in Chemistry.
• Carbon nanotube — a cylindrical form of carbon made by rolling up a graphene sheet.
• Quantum Hall effect — a quantum phenomenon in which electrical conductivity in a material changes in fixed steps under a magnetic field.
• Klein tunnelling — a quantum effect, predicted by Oskar Klein, in which particles pass through an energy barrier that should normally block them.
• Dirac point — the point in graphene's electronic structure where its energy bands meet, giving electrons behaviour similar to massless particles.
• Fermi level — the highest energy level occupied by electrons in a material at low temperature, used to describe a material's electrical behaviour.
• Doping — adding or removing electrons from a material, for example by exposing graphene to gases, to change its conductivity.
• Royal Swedish Academy of Sciences — the independent body, founded in 1739, that awards the Nobel Prize in Physics each year.

Common errors and misconceptions

• Misconception: Graphene was discovered using complex, expensive laboratory machinery. Correct: The original isolation used ordinary adhesive tape peeling flakes off pencil-type graphite.
• Misconception: Graphite and graphene are the same material. Correct: Graphite is a stack of many graphene layers; graphene is a single, one-atom-thick layer.
• Misconception: Graphene was a completely unknown material before 2010. Correct: Its theoretical electronic structure had been studied since 1947, but it was not experimentally isolated and measured until 2004.
• Misconception: Geim and Novoselov invented carbon. Correct: They isolated and characterised a new form of an already well-known element, carbon.
• Misconception: Graphene's electrons are literally massless particles like photons. Correct: Their motion is described by equations similar to those for massless particles, but they are still electrons with normal mass in free space.
• Misconception: Graphene products such as fast computers and super-strong materials were ready for use by 2010. Correct: The sources describe most applications as still being tested, with outcomes uncertain.
• Misconception: Only one research group worked on thin carbon films. Correct: Other groups, including one led by W. A. de Heer and one led by P. Kim, pursued alternative methods around the same period.

Exam-style questions with model answers

Q1. In which year was the Nobel Prize in Physics 2010 announced? [1 mark]

1. It was announced in 2010 (on 5 October).

Q2. State the official citation for the Nobel Prize in Physics 2010. [2 marks]

1. The prize was awarded "for groundbreaking experiments regarding the two-dimensional material graphene".

Q3. Explain what makes graphene a "two-dimensional" material. [3 marks]

1. Graphene consists of carbon atoms arranged in a hexagonal, honeycomb lattice that is only one atom thick.
2. Atoms are added along its length and width, but there is no additional layer of atoms in the height direction.
3. Because of this, electrons within the material can only move in two directions rather than three, giving graphene unique electronic behaviour not seen in bulk, three-dimensional carbon.

Q4. Describe the method Geim and Novoselov used to obtain graphene from graphite. [4 marks]

1. They started with an ordinary piece of graphite, the material found in pencils, which is made of many stacked graphene layers.
2. Using regular adhesive tape, they repeatedly pressed it onto the graphite and peeled it away, splitting the stack into progressively thinner flakes.
3. The flakes were transferred onto a plate of oxidised silicon, where differences in thickness appeared as different colours under an ordinary microscope, letting them identify single-layer flakes.
4. Once identified, the single-atom-thick flakes were patterned and connected to electrodes so their electrical properties could be measured directly.

Q5. Why did many scientists doubt, before 2004, that a material as thin as graphene could be isolated? [3 marks]

1. Many physicists believed that an ultra-thin, single-atom crystal would be unstable at room temperature.
2. They thought such a thin sheet would simply crinkle, roll up, or even vanish rather than remain flat.
3. Earlier experimental attempts had only managed to make films of less than 100 atoms thick, never a confirmed true single layer that could also be electrically tested.

Q6. Discuss the unusual electronic and physical properties of graphene reported by the Nobel committee, and explain why they matter for both science and future technology. [6 marks]

1. Graphene's carbon lattice is nearly free of defects because of strong but flexible chemical bonding between atoms, which also lets the material stretch by up to 20% without breaking.
2. This near-perfect lattice allows electrons to travel long distances without scattering, unlike in ordinary conductors where electrons repeatedly collide and lose energy.
3. Electrons in graphene behave as if they have no mass, following equations similar to those used for massless particles in particle physics, which let scientists study quantum effects such as a variant of Klein tunnelling, predicted by Oskar Klein in 1929, at laboratory scale.
4. Graphene conducts electricity as well as copper and conducts heat better than any other known material.
5. It is almost completely transparent yet dense enough to block even helium atoms.
6. These combined properties made graphene attractive for transparent touch screens, light panels, solar cells, very fast transistors, sensitive sensors, and lightweight composite materials for vehicles and aircraft, though the sources describe most such applications as still being explored and uncertain rather than finished products.

Q7. Who were the two laureates of the Nobel Prize in Physics 2010, and what was their earlier working relationship? [3 marks]

1. The laureates were Andre Geim and Konstantin Novoselov, both affiliated with the University of Manchester at the time of the award.
2. They had worked together for a long time before the prize, with Novoselov first working with Geim as a PhD student in the Netherlands.
3. Novoselov later followed Geim to the United Kingdom, and both had originally studied and begun their careers as physicists in Russia.

Q8. Name three forms of carbon besides graphene mentioned in connection with this prize, and briefly describe each. [4 marks]

1. Graphite is a common form of carbon consisting of many graphene layers stacked loosely on top of each other, found in ordinary pencils.
2. Fullerenes are football-shaped cage molecules made of carbon atoms, a discovery honoured by the 1996 Nobel Prize in Chemistry.
3. Carbon nanotubes are cylindrical forms of carbon formed by conceptually rolling up a graphene sheet into a tube.

Key takeaways

• The Nobel Prize in Physics 2010 honoured Andre Geim and Konstantin Novoselov for isolating and characterising graphene.
• Graphene is a single, one-atom-thick layer of carbon atoms arranged in a hexagonal honeycomb lattice.
• Both laureates were affiliated with the University of Manchester, United Kingdom, at the time of the award, sharing the prize equally.
• They produced graphene using mechanical exfoliation, peeling graphite with adhesive tape and identifying single layers optically.
• Graphene's electrons behave as if massless, enabling tests of quantum effects such as Klein tunnelling.
• The material is extremely strong, highly conductive of both heat and electricity, and almost completely transparent.
• Their foundational paper was published in Science in October 2004, igniting a rapid expansion of graphene research.
• Possible future applications described by the committee include touch screens, fast transistors, sensors and lightweight composite materials.

Test yourself

What is graphene made of?

Graphene is made of carbon atoms arranged in a single, one-atom-thick hexagonal honeycomb lattice.

Which university were both 2010 physics laureates affiliated with?

Both Andre Geim and Konstantin Novoselov were affiliated with the University of Manchester in the United Kingdom.

What everyday tool did Geim and Novoselov use to isolate graphene?

They used ordinary adhesive tape to repeatedly peel thin flakes off a piece of graphite.

In what year was the key graphene paper published, and in which journal?

The key paper describing graphene's isolation was published in Science in October 2004.

What quantum effect, predicted by Oskar Klein, was later tested using graphene?

Klein tunnelling, in which particles pass through an energy barrier that should normally block them, was tested using graphene.

How does graphene compare to copper and steel in conductivity and strength?

Graphene conducts electricity as well as copper, conducts heat even better, and is far stronger than steel.

When was the Nobel Prize in Physics 2010 announced?

The prize was announced on 5 October 2010 by the Royal Swedish Academy of Sciences.

Name one possible future application of graphene mentioned by the Nobel committee.

Possible applications mentioned include transparent touch screens, fast transistors, sensitive gas sensors and lightweight composite materials.