Electron hole

In <a href="/facts/Physics/a7aH2y08">physics</a>, <a href="/facts/Chemistry/SrNqkGVm">chemistry</a>, and <a href="/facts/Electronic_engineering/WCSVulpu">electronic engineering</a>, an electron hole (often simply called a hole) is a <a href="/facts/Quasiparticle/Bpx2MNpb">quasiparticle</a> denoting the lack of an electron at a position where one could exist in an <a href="/facts/Atom/FoQ4kGN5">atom</a> or <a href="/facts/Crystal_structure/bJ4bCeHd">atomic lattice</a>. Since in a normal atom or crystal lattice the negative charge of the electrons is balanced by the positive charge of the <a href="/facts/Atomic_nucleus/orpIm5Xl">atomic nuclei</a>, the absence of an electron leaves a net positive charge at the hole's location.
Holes in a metal or <a href="/facts/Semiconductor/zFf3mGTE">semiconductor</a> <a href="/facts/Crystal_lattice/7gQKTsXk">crystal lattice</a> can move through the lattice as electrons can, and act similarly to <a href="/facts/Electric_charge/xxsBfmlB">positively-charged</a> particles. They play an important role in the operation of <a href="/facts/Semiconductor_device/6W3ryr50">semiconductor devices</a> such as <a href="/facts/Transistor/Bmr8zwL0">transistors</a>, <a href="/facts/Diode/JyaoyGnk">diodes</a> (including <a href="/facts/Light-emitting_diodes/gE8x4MDb">light-emitting diodes</a>) and <a href="/facts/Integrated_circuit/fjn6vg7C">integrated circuits</a>. If an electron is excited into a higher state it leaves a hole in its old state. This meaning is used in <a href="/facts/Auger_electron_spectroscopy/GTcxGXrA">Auger electron spectroscopy</a> (and other <a href="/facts/X-ray/wseP79cN">x-ray</a> techniques), in <a href="/facts/Computational_chemistry/KyuCgRV3">computational chemistry</a>, and to explain the low electron-electron scattering-rate in crystals (metals and semiconductors). Although they act like elementary particles, holes are rather <a href="/facts/Quasiparticle/Bpx2MNpb">quasiparticles</a>; they are different from the <a href="/facts/Positron/HgV4zBzA">positron</a>, which is the <a href="/facts/Antiparticle/7Ic43ThI">antiparticle</a> of the electron. (See also <a href="/facts/Dirac_sea/x40KMcu3">Dirac sea</a>.)
In <a href="/facts/Crystal/e2R2mk3E">crystals</a>, <a href="/facts/Electronic_band_structure/W5o7oE2R">electronic band structure</a> calculations lead to an <a href="/facts/Effective_mass_(solid-state_physics)/I8acHGPd">effective mass</a> for the electrons that is typically negative at the top of a band. The <a href="/facts/Negative_mass/dqGf2T4m">negative mass</a> is an unintuitive concept, and in these situations, a more familiar picture is found by considering a positive charge with a positive mass.

Electron hole open-in-new

Electron hole