Holes

Our Take

Where electrons *aren’t*. It may seem dumb that we treat the lack of something as a particle, but it’s really important in modeling bandgaps and other important stuff with semiconductors.

Book Definition

The absence of a valence electron in a covalent bond structure. The hole exhibits a positive charge.

Grob’s Basic Electronics, 11th Edition by Mitchel E. Schultz

The absence of an electron in the valence band of an atom.

Electronic Devices : Conventional Current Version, 9th Edition by Thomas L. Floyd

Wikipedia

In physics, chemistry, and electronic engineering, an electron hole (often simply called a hole) is the lack of an electron at a position where one could exist in an atom or atomic lattice. Since in a normal atom or crystal lattice the negative charge of the electrons is balanced by the positive charge of the atomic nuclei, the absence of an electron leaves a net positive charge at the hole's location. Holes are not actually particles, but rather quasiparticles; they are different from the positron, which is the antiparticle of the electron. (See also Dirac sea.)

Holes in a metal^[1] or semiconductor crystal lattice can move through the lattice as electrons can, and act similarly to positively-charged particles. They play an important role in the operation of semiconductor devices such as transistors, diodes and integrated circuits. If an electron is excited into a higher state it leaves a hole in its old state. This meaning is used in Auger electron spectroscopy (and other x-ray techniques), in computational chemistry, and to explain the low electron-electron scattering-rate in crystals (metals, semiconductors).

In crystals, electronic band structure calculations lead to an effective mass for the electrons, which is typically negative at the top of a band. The negative mass is an unintuitive concept,^[2] and in these situations a more familiar picture is found by considering a positive charge with a positive mass.

https://en.wikipedia.org/wiki/Electron_hole