[syn: semiconductor device, semiconductor unit, semiconductor]
WordNet (r) 3.0 (2006):
n 1: a substance as germanium or silicon whose electrical
conductivity is intermediate between that of a metal and an
insulator; its conductivity increases with temperature and
in the presence of impurities [syn: semiconductor,
2: a conductor made with semiconducting material [syn:
semiconductor device, semiconductor unit,
The Free On-line Dictionary of Computing (18 March 2015):
A material, typically crystaline, which allows
current to flow under certain circumstances. Common
semiconductors are silicon, germanium, gallium arsenide.
Semiconductors are used to make diodes, transistors and
other basic "solid state" electronic components.
As crystals of these materials are grown, they are "doped"
with traces of other elements called donors or acceptors
to make regions which are n- or p-type respectively for the
electron model or p- or n-type under the hole model.
Where n and p type regions adjoin, a junction is formed which
will pass current in one direction (from p to n) but not the
other, giving a diode.
One model of semiconductor behaviour describes the doping
elements as having either free electrons or holes dangling
at the points in the crystal lattice where the doping elements
replace one of the atoms of the foundation material. When
external electrons are applied to n-type material (which
already has free electrons present) the repulsive force of
like charges causes the free electrons to migrate toward the
junction, where they are attracted to the holes in the p-type
material. Thus the junction conducts current.
In contrast, when external electrons are applied to p-type
material, the attraction of unlike charges causes the holes to
migrate away from the junction and toward the source of
external electrons. The junction thus becomes "depleted" of
its charge carriers and is non-conducting.