Preferred Label : photodiode;
IUPAC acronym : PIN;
IUPAC definition : A two-electrode, radiation-sensitive junction formed in a semiconductive material.
A junction is formed by two successive regions of a semiconductive material having,
respectively, an excess of electrons (n-type) or holes (p-type). A bias potential
applied to the detector creates a region at the interface that is depleted of majority
carriers. Each incident photon produces electron-hole pairs in the depletion region
resulting in a measurable signal current. The photodiode can be operated either with
zero bias in the photovoltaic mode where the photodiode is actually generating the
electric potential supplied to the load. In a biased mode, the photoconductive mode,
the reverse current is proportional to the irradiation. A Schottky-barrier photodiode
is constructed by deposition of a metal film on a semiconductor surface in such a
way that no interface layer is present. The barrier thickness depends on the impurity
dopant concentration in the semiconductor layer. The incident radiation generates
electon-hole pairs within the depletion region of the barrier where they are collected
efficiently and rapidly by the built-in field. A PIN (p-intrinsic-n) diode is a planar
diffused diode consisting of a single crystal having an intrinsic (undoped or compensated)
region sandwiched between p- and n-type regions. A bias potential applied across the
detector depletes the intrinsic region of charge carriers, constituting the radiation-sensitive
detector volume. The number of electron-hole pairs produced is dependent on the energy
of the incident photons. An avalanche photodiode is a photodiode in which the photogenerated
electron-hole pairs are accelerated by a bias potential near to breakdown potential
so that further electron-hole pairs are formed leading to saturation of the photocurrent.
This operational mode for photon counting is the so-called Geiger mode, similar to
that of the gas filled Geiger counter. Avalanche photodiodes can also be operated
in the proportional mode.;
Origin ID : P04598;
Automatic exact mappings (from CISMeF team)
See also
A two-electrode, radiation-sensitive junction formed in a semiconductive material.
A junction is formed by two successive regions of a semiconductive material having,
respectively, an excess of electrons (n-type) or holes (p-type). A bias potential
applied to the detector creates a region at the interface that is depleted of majority
carriers. Each incident photon produces electron-hole pairs in the depletion region
resulting in a measurable signal current. The photodiode can be operated either with
zero bias in the photovoltaic mode where the photodiode is actually generating the
electric potential supplied to the load. In a biased mode, the photoconductive mode,
the reverse current is proportional to the irradiation. A Schottky-barrier photodiode
is constructed by deposition of a metal film on a semiconductor surface in such a
way that no interface layer is present. The barrier thickness depends on the impurity
dopant concentration in the semiconductor layer. The incident radiation generates
electon-hole pairs within the depletion region of the barrier where they are collected
efficiently and rapidly by the built-in field. A PIN (p-intrinsic-n) diode is a planar
diffused diode consisting of a single crystal having an intrinsic (undoped or compensated)
region sandwiched between p- and n-type regions. A bias potential applied across the
detector depletes the intrinsic region of charge carriers, constituting the radiation-sensitive
detector volume. The number of electron-hole pairs produced is dependent on the energy
of the incident photons. An avalanche photodiode is a photodiode in which the photogenerated
electron-hole pairs are accelerated by a bias potential near to breakdown potential
so that further electron-hole pairs are formed leading to saturation of the photocurrent.
This operational mode for photon counting is the so-called Geiger mode, similar to
that of the gas filled Geiger counter. Avalanche photodiodes can also be operated
in the proportional mode.