graphene

History

In 2004, Andre Geim and Konstantin Novoselov obtained graphene by peeling layers of graphite with ordinary Scotch tape. Discovering a film one atom thick, they made a breakthrough that earned the Nobel Prize.

How it works

Carbon atoms in graphene are tightly bound into a flexible network. Free electrons zip through it with minimal hindrance, like a beam of light. Such behavior is usually characteristic of particles at near-light speeds, but in graphene it appears already under ordinary conditions.

History

In 2004, Andre Geim and Konstantin Novoselov obtained graphene by peeling layers of graphite with ordinary Scotch tape. Discovering a film one atom thick, they made a breakthrough that earned the Nobel Prize.

How it works

Carbon atoms in graphene are tightly bound into a flexible network. Free electrons zip through it with minimal hindrance, like a beam of light. Such behavior is usually characteristic of particles at near-light speeds, but in graphene it appears already under ordinary conditions.

History

Theoretical studies of graphite layers began with P.R. Wallace in 1947. The term 'graphene' was introduced in 1987. The breakthrough occurred in 2004, when Andre Geim and Konstantin Novoselov, using Scotch tape, exfoliated a monolayer of graphite, proving the stability of two-dimensional crystals. In 2010 they received the Nobel Prize in Physics. This discovery triggered a wave of studies of other two-dimensional materials.

How it works

The electronic properties of graphene are determined by the symmetry of its lattice and the tight-binding approximation. Near the vertices of the Brillouin zone, the dispersion is linear: E = ħ v_F |k|, where v_F is about 10⁶ m/s. The chirality of the carriers (pseudospin rigidly linked to the direction of motion) suppresses backscattering, ensuring ballistic transport. Mechanical strength is provided by the high energy of sp²-bonds. By applying a voltage, one can change the type of conductivity (electrons or holes), so graphene is an ambipolar semimetal. The gapless band structure hinders application in digital logic.

Open problems & fun facts

Scalable production of high-quality graphene; Creation and control of a bandgap for transistors; Integration with silicon technology; Environmental safety and toxicity of nanofilms; Achieving series uniformity for industrial applications

💡 Graphene one atom thick is impermeable even to helium atoms—the smallest particles of inert gas. Yet it lets water through, acting as a molecular sieve.