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How do electrons and holes carry electric charge through graphene?

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graphene: atomic force microscopy — graphene Atomic force microscopy image of water structures that were trapped beneath a sheet of graphene one atom thick.

In graphene, electrons and holes act as charge carriers that facilitate electrical conductivity, similar to their role in semiconductors. However, unlike conventional semiconductors, graphene does not possess an insulator state; it maintains finite conductivity even at zero doping.1

The movement of these carriers is governed by the material's unique honeycomb lattice, which consists of two sublattices (A and B). This geometry grants electrons and holes an internal degree of freedom known as pseudospin, which mimics the spin of subatomic particles. Consequently, these charge carriers behave like ultra-relativistic quantum particles—analogous to particles and antiparticles in quantum electrodynamics—though they travel at approximately 1/300th the speed of light.1

By applying a gate voltage or using chemical doping, one can induce either electron or hole conductivity, allowing for the transport of charge across the two-dimensional carbon sheet. Because of their high mobility, these carriers make graphene a subject of intense interest for future electronic applications.1