Donor (semiconductors)


Donor (semiconductors)

In semiconductor physics, a donor is a dopant atom that, when added to a semiconductor, can form n-type regions.

Phosphorus atom acting as a donor in the simplified 2D Silicon lattice.

For example, when silicon (Si), having four valence electrons, needs to be doped as an n-type semiconductor, elements from group V like phosphorus (P) or arsenic (As) can be used because they have five valence electrons. A dopant with five valence electrons is also called a pentavalent impurity. Other pentavalent dopants are antimony (Sb) and bismuth (Bi).

When substituting a Si atom in the crystal lattice, four of the valence electrons of phosphorus form covalent bonds with the neighbouring Si atoms but the fifth one remains weakly bonded. At room temperature all the fifth electrons are liberated, can move around the Si crystal and can carry a current, act as charge carriers. The initially neutral donor becomes positively charged (ionised).

See also


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Donor — A donor in general is a person who donates something voluntarily. Usually used to represent a form of pure altruism but sometimes used when the payment for a service is recognised by all parties as representing less than the value of the donation …   Wikipedia

  • Acceptor (semiconductors) — In semiconductors physics the term acceptor is used to generically indicate a dopant atom that added to a semiconductor can form p type regions. For example, when Silicon (Si), having four valence electrons, needs to be doped as an p type… …   Wikipedia

  • Semiconductor — Citations missing|date=March 2008A semiconductor is a solid material that has electrical conductivity in between a conductor and an insulator; it can vary over that wide range either permanently or dynamically. [. They are used in many… …   Wikipedia

  • Extrinsic semiconductor — An extrinsic semiconductor is a semiconductor that has been doped , that is, into which a doping agent has been introduced, giving it different electrical properties than the intrinsic (pure) semiconductor. Doping involves adding dopant atoms to… …   Wikipedia

  • Solar cell — A solar cell made from a monocrystalline silicon wafer …   Wikipedia

  • Charge-transfer complex — A charge transfer complex (CT complex) or electron donor acceptor complex is an association of two or more molecules, or of different parts of one very large molecule, in which a fraction of electronic charge is transferred between the molecular… …   Wikipedia

  • Doping (semiconductor) — In semiconductor production, doping intentionally introduces impurities into an extremely pure (also referred to as intrinsic) semiconductor for the purpose of modulating its electrical properties. The impurities are dependent upon the type of… …   Wikipedia

  • Crystallographic defects in diamond — Synthetic diamonds of various colors grown by the high pressure high temperature technique, the diamond size is 2 mm …   Wikipedia

  • Photoconductive atomic force microscopy — (pc AFM) is a scientific technique.. Multi layer photovoltaic cells have gained popularity since mid 1980s.[1] At the time, research was primarily focused on single layer photovoltaic (PV) devices between two electrodes, in which PV properties… …   Wikipedia

  • N-type semiconductor — N type semiconductors are a type of extrinsic semiconductor where the dopant atoms are capable of providing extra conduction electrons to the host material (e.g. phosphorus in silicon). This creates an excess of negative (n type) electron charge… …   Wikipedia