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单词 hole
释义
hole

Physics
  • A vacant electron position in the lattice structure of a solid that behaves like a mobile positive charge carrier with a negative rest energy. See semiconductor.


Chemistry
  • 1. A vacant electron position in the lattice structure of a solid that behaves like a mobile positive charge carrier.

    2. A vacant electron position in one of the inner orbitals of an atom.


Electronics and Electrical Engineering
  • An empty energy level in the valence band of a semiconductor due to an electron being lost from the band by thermal excitation (see electron-hole pair) or being trapped by an acceptor impurity (see semiconductor). The total current resulting from electrons in a filled valence band is zero:

    j=nev=eΣi=lnvi=0

    where j is the current density, n and e the electron density and charge, and v the average velocity of electrons in the valence band. If the jth electron is excited to the conduction band or trapped by an impurity then

    eΣi=l,ijnvi=evj

    The net effect of the mobile electrons occupying all but the jth energy level is therefore equivalent to the effect of a single positive electronic charge ‘occupying’ the vacant level and hence termed a hole. The hole velocity is equal to the velocity of an electron in the same energy level.

    Under the influence of an electric field holes can drift through the material by a process of continuous exchange with adjacent electrons (see hole conduction). They therefore act as mobile positive charge carriers in the valence band and are the majority carriers in p-type semiconductors.


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