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When silicon (Si), having four valence electrons, is doped with elements from group III of the periodic table, such as boron (B) and aluminium (Al), both having three valence electrons, a p-type semiconductor is formed. These dopant elements represent trivalent impurities. Other trivalent dopants include indium (In) and gallium (Ga). [1]
A compound semiconductor is a semiconductor compound composed of chemical elements of at least two different species. These semiconductors form for example in periodic table groups 13–15 (old groups III–V), for example of elements from the Boron group (old group III, boron, aluminium, gallium, indium) and from group 15 (old group V, nitrogen, phosphorus, arsenic, antimony, bismuth).
An (intrinsic) semiconductor has a band gap that is smaller than that of an insulator and at room temperature, significant numbers of electrons can be excited to cross the band gap. [23] A pure semiconductor, however, is not very useful, as it is neither a very good insulator nor a very good conductor.
In semiconductor physics, a donor is a dopant atom that, when added to a semiconductor, can form a n-type region. Phosphorus atom acting as a donor in the simplified 2D silicon lattice. For example, when silicon (Si), having four valence electrons , is to be doped as a n-type semiconductor , elements from group V like phosphorus (P) or arsenic ...
Doping of a pure silicon array. Silicon based intrinsic semiconductor becomes extrinsic when impurities such as boron and antimony are introduced.. In semiconductor production, doping is the intentional introduction of impurities into an intrinsic (undoped) semiconductor for the purpose of modulating its electrical, optical and structural properties.
The carrier density is important for semiconductors, where it is an important quantity for the process of chemical doping. Using band theory, the electron density, is number of electrons per unit volume in the conduction band. For holes, is the number of holes per unit volume in the valence band.
A solid substance can conduct electric current only if it contains charged particles, electrons, which are free to move about and not attached to atoms.In a metal conductor, it is the metal atoms that provide the electrons; typically each metal atom releases one of its outer orbital electrons to become a conduction electron which can move about throughout the crystal, and carry electric current.
The conduction of current of intrinsic semiconductor is enabled purely by electron excitation across the band-gap, which is usually small at room temperature except for narrow-bandgap semiconductors, like Hg 0.8 Cd 0.2 Te. The conductivity of a semiconductor can be modeled in terms of the band theory of solids.