An electron hole is the conceptual and mathematical opposite of an electron, useful in the study of physics and chemistry. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties The concept describes the lack of an electron. It is different from the positron, which is the antimatter duplicate of the electron. The positrons or antielectron is the Antiparticle or the Antimatter counterpart of the Electron. In Particle physics and Quantum chemistry, antimatter is the extension of the concept of the Antiparticle to Matter, where antimatter is composed

The electron hole was introduced into calculations for the following two situations:

• 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). Auger electron spectroscopy (AES Auger oːʒeː in French is a common analytical technique used specifically in the study of surfaces and more generally in the area of X-radiation (composed of X-rays) is a form of Electromagnetic radiation. Computational chemistry is a branch of Chemistry that uses computers to assist in solving chemical problems The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across A semiconductor' is a Solid material that has Electrical conductivity in between a conductor and an insulator; it can vary over that
• In crystals, band structure calculations lead to an effective mass for the charge carriers, which can be negative. In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating In Solid-state physics, the electronic band structure (or simply band structure) of a Solid describes ranges of Energy that an Electron Inspired by the Hall effect, Newton's law is used to attach the negative sign onto the charge. The Hall effect refers to the Potential difference ( Hall voltage) on the opposite sides of an Electrical conductor through which there is an Electric Newton's laws of motion are three Physical laws which provide relationships between the Forces acting on a body and the motion of the

Solid state physics

When an electron leaves a helium atom, it leaves an electron hole in its place. Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical This causes the helium atom to become positively charged.

In solid state physics, an electron hole (usually referred to simply as a hole) is the absence of an electron from the otherwise full valence band. Solid-state physics, the largest branch of Condensed matter physics, is the study of rigid Matter, or Solids The bulk of solid-state physics theory and In Solids the valence band is the highest range of Electron energies where electrons are normally present at Absolute zero. A full (or nearly full) valence band is present in semiconductors and insulators. A semiconductor' is a Solid material that has Electrical conductivity in between a conductor and an insulator; it can vary over that An insulator, also called a Dielectric, is a material that resists the flow of Electric current. The concept of a hole is essentially a simple way to analyze the electronic transitions within the valence band.

Hole conduction can be explained by the following analogy. Imagine a row of people seated in an auditorium, where there are no spare chairs. Someone in the middle of the row wants to leave, so he jumps over the back of the seat into an empty row, and walks out. The empty row is analogous to the conduction band, and the person walking out is analogous to a free electron. In the Physics field of Semiconductors and insulators the conduction band is the range of Electron Energy, higher than that of the

Now imagine someone else comes along and wants to sit down. The empty row has a poor view; so he does not want to sit there. Instead, a person in the crowded row moves into the empty seat the first person left behind. The empty seat moves one spot closer to the edge and the person waiting to sit down. The next person follows, and the next, et cetera. One could say that the empty seat moves towards the edge of the row. Once the empty seat reaches the edge, the new person can sit down.

In the process everyone in the row has moved along. If those people were negatively charged (like electrons), this movement would constitute conduction. Electrical conductivity or specific conductivity is a measure of a material's ability to conduct an Electric current. If the seats themselves were positively charged, then only the vacant seat would be positive. This is a very simple model of how hole conduction works.

In reality, due to the crystal structure properties, the hole is actually not localized to a single position as described in the previous example. Rather, the hole is delocalized and spans an area in the crystal lattice covering many hundreds of unit cells. In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. This is equivalent to the idea that we cannot tell which broken bond corresponds to the 'missing' electron, and is supported by uncertainty theorems from quantum mechanics. Quantum mechanics is the study of mechanical systems whose dimensions are close to the Atomic scale such as Molecules Atoms Electrons

Instead of analyzing the movement of an empty state in the valence band as the movement of billions of separate electrons, physicists propose a single imaginary particle called a "hole". In an applied electric field, all the electrons move one way, so the hole moves the other way. In Physics, the space surrounding an Electric charge or in the presence of a time-varying Magnetic field has a property called an electric field (that can If a hole associates itself with a neutral atom, that atom loses an electron and becomes positive. The physicists therefore say that the hole must have positive charge—in fact, they assign a charge of +e, precisely the opposite of the electron charge. Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction.

Using Coulomb's law, we can calculate the force on the "hole" due to an electric field. ---- Bold text Coulomb's law', developed in the 1780s by French physicist Charles Augustin de Coulomb, may be stated in scalar form Physicists then propose an effective mass which will relate the (imaginary) force on the (imaginary) hole to the acceleration of that hole. In Solid state physics, a particle's effective mass is the Mass it seems to carry in the semiclassical model of transport in a Crystal. In some semiconductors, such as silicon, effective mass is dependent on direction (anisotropic), however a value averaged over all directions can be used for some macroscopic calculations. Anisotropy (pronounced with stress on the third syllable ˌænaɪˈsɒtrəpi is the property of being directionally dependent as opposed to Isotropy, which means homogeneity

In most of the semiconductors, the effective mass of a hole is larger than that of an electron. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J This results in less mobility for holes under the influence of an electric field and this may slow down the speed of the electronic device made of that semiconductor. In Physics, the space surrounding an Electric charge or in the presence of a time-varying Magnetic field has a property called an electric field (that can This is one major reason for adopting electrons as the primary charge carriers, whenever possible in semiconductor devices instead of holes.

Holes in quantum chemistry

An alternate meaning for the term electron hole is used in computational chemistry. Computational chemistry is a branch of Chemistry that uses computers to assist in solving chemical problems In coupled cluster methods, the ground (or lowest energy) state of a molecule is interpreted as the "vacuum state"—conceptually, in this state there are no electrons. Coupled cluster ( CC) is a numerical technique used for describing Many-body systems Its most common use is as one of several quantum chemical In this scheme, the absence of an electron from a normally-filled state is called a "hole" and is treated as a particle, and the presence of an electron in a normally-empty state is simply called an "electron". This terminology is almost identical to that used in solid-state physics.

See also

• Bandgap
• Carrier generation and recombination
• Effective mass
• Electrical conduction
• Semiconductor