Electronic properties and band structure of graphene

Graphene is amazing for its very special electronic (electrical) properties. Unlike most other two-dimensional materials, it is a zero-bandgap semiconductor, and its properties depend on its special band structure. The band structure of an ideal graphene is a completely symmetrical cone valence band and conduction band symmetrically distributed above and below the Fermi level. The intersection of the conduction band and the valence band is Dirac point.

Unlike ordinary metals or semiconductors, the electrons in graphene do not follow Schr?dinger's equation, but rather follow the Dirac equation. This is because: ① each C-C bond has a bonding orbital and an anti-bond orbit, and the C-C bond is completely symmetrical in the plane; ② each π bond in the entire graphene molecular structure is conjugated to each other Huge conjugated large π bond, electrons or holes can move at a very high Fermi velocity (vF≈106m? S-1) in such a huge conjugate system, showing zero mass behavior, fundamentally speaking Many electrons in graphene behave similarly to two-dimensional electron gas, with only 1/10 the mass of free electrons.