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An exciton is a bound state of an electron and an electron hole which are attracted to each other by the electrostatic Coulomb force resulting from their opposite charges. It is an electrically neutral quasiparticle regarded as an elementary excitation primarily in condensed matter, such as insulators, semiconductors, some metals, and in some liquids.
For one electron and one hole, this problem is analogous to the Schrödinger equation of the hydrogen atom; and the bound-state solutions are called excitons. When an exciton's radius extends over several unit cells, it is referred to as a Wannier exciton in contrast to Frenkel excitons whose size is comparable with the unit cell. An excited ...
An electron as affected by the other forces and interactions in the solid: electron Electron hole (hole) A lack of electron in a valence band: crystal lattice Exciton: A bound state of an electron and a hole (See also: biexciton) electron, hole Exciton-polariton: A bound state of an exciton and a photon. photon, exciton Ferron
When an electron leaves a helium atom, it leaves an electron hole in its place. This causes the helium atom to become positively charged. In physics, chemistry, and electronic engineering, an electron hole (often simply called a hole) is a quasiparticle denoting the lack of an electron at a position where one could exist in an atom or atomic lattice.
Electron and hole trapping in the Shockley-Read-Hall model. In the SRH model, four things can happen involving trap levels: [11] An electron in the conduction band can be trapped in an intragap state. An electron can be emitted into the conduction band from a trap level. A hole in the valence band can be captured by a trap.
The electron quasiparticle has the same charge and spin as a "normal" (elementary particle) electron, and like a normal electron, it is a fermion. However, its mass can differ substantially from that of a normal electron; see the article effective mass. [1] Its electric field is also modified, as a result of electric field screening.
Electron excitation is the transfer of a bound electron to a more energetic, but still bound state. This can be done by photoexcitation (PE), where the electron absorbs a photon and gains all its energy [1] or by collisional excitation (CE), where the electron receives energy from a collision with another, energetic electron. [2]
However, a real exciton is a true two-particle correlation because one must then have a correlation between one electron to another hole. Therefore, the appearance of exciton resonances in the polarization does not signify the presence of excitons because is a single-particle transition amplitude. The excitonic resonances are a direct ...