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  2. Valence and conduction bands - Wikipedia

    en.wikipedia.org/wiki/Valence_and_conduction_bands

    In solid-state physics, the valence band and conduction band are the bands closest to the Fermi level, and thus determine the electrical conductivity of the solid. In nonmetals, the valence band is the highest range of electron energies in which electrons are normally present at absolute zero temperature, while the conduction band is the lowest range of vacant electronic states.

  3. Electronic band structure - Wikipedia

    en.wikipedia.org/wiki/Electronic_band_structure

    In semimetals the bands are usually referred to as "conduction band" or "valence band" depending on whether the charge transport is more electron-like or hole-like, by analogy to semiconductors. In many metals, however, the bands are neither electron-like nor hole-like, and often just called "valence band" as they are made of valence orbitals. [11]

  4. Band diagram - Wikipedia

    en.wikipedia.org/wiki/Band_diagram

    The conduction band edge may also be indicated in an insulator, simply to demonstrate band bending effects. E V : The valence band edge likewise should be indicated in situations where electrons (or holes ) are transported through the top of the valence band such as in a p -type semiconductor .

  5. Band gap - Wikipedia

    en.wikipedia.org/wiki/Band_gap

    In graphs of the electronic band structure of solids, the band gap refers to the energy difference (often expressed in electronvolts) between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. It is the energy required to promote an electron from the valence band to the conduction band.

  6. Direct and indirect band gaps - Wikipedia

    en.wikipedia.org/wiki/Direct_and_indirect_band_gaps

    Energy vs. crystal momentum for a semiconductor with a direct band gap, showing that an electron can shift from the highest-energy state in the valence band (red) to the lowest-energy state in the conduction band (green) without a change in crystal momentum. Depicted is a transition in which a photon excites an electron from the valence band to ...

  7. File:Solid state electronic band structure.svg - Wikipedia

    en.wikipedia.org/wiki/File:Solid_state...

    Since the 5.5 eV band gap is much larger than the thermal energy of most electrons in the crystal, very few electrons acquire the energy to jump the gap and become conduction electrons. This is why diamond is an electrical insulator. The shape of the graph (right) is only approximately correct. It also only shows the band structure of the outer ...

  8. Electronic properties of graphene - Wikipedia

    en.wikipedia.org/wiki/Electronic_properties_of...

    Electronic band structure of graphene. Valence and conduction bands meet at the six vertices of the hexagonal Brillouin zone and form linearly dispersing Dirac cones. When atoms are placed onto the graphene hexagonal lattice, the overlap between the p z (π) orbitals and the s or the p x and p y orbitals is zero by symmetry.

  9. Charge carrier density - Wikipedia

    en.wikipedia.org/wiki/Charge_carrier_density

    For holes, is the number of holes per unit volume in the valence band. To calculate this number for electrons, we start with the idea that the total density of conduction-band electrons, n 0 {\displaystyle n_{0}} , is just adding up the conduction electron density across the different energies in the band, from the bottom of the band E c ...