Semiconductor

A semiconductor is a material with electrical
conductivity due to electron flow (as opposed to
ionic conductivity) intermediate in magnitude
between that of a conductor and an insulator.
This means a conductivity roughly in the range of
103 to 10−8 siemens per centimeter.
Semiconductor materials are the foundation of
modern electronics, including radio, computers,
telephones, and many other devices. Such
devices include transistors, solar cells, many
kinds of diodes including the light-emitting diode,
the silicon controlled rectifier, and digital and
analog integrated circuits. Similarly,
semiconductor solar photovoltaic panels directly
convert light energy into electrical energy. In a
metallic conductor, current is carried by the flow
of electrons. In semiconductors, current is often
schematized as being carried either by the flow of
electrons or by the flow of positively charged
" holes" in the electron structure of the material.
Actually, however, in both cases only electron
movements are involved.
Common semiconducting materials are
crystalline solids, but amorphous and liquid
semiconductors are known. These include
hydrogenated amorphous silicon and mixtures of
arsenic, selenium and tellurium in a variety of
proportions. Such compounds share with better
known semiconductors intermediate conductivity
and a rapid variation of conductivity with
temperature, as well as occasional negative
resistance. Such disordered materials lack the
rigid crystalline structure of conventional
semiconductors such as silicon and are generally
used in thin film structures, which are less
demanding for as concerns the electronic quality
of the material and thus are relatively insensitive
to impurities and radiation damage. Organic
semiconductors, that is, organic materials with
properties resembling conventional
semiconductors, are also known.
Silicon is used to create most semiconductors
commercially. Dozens of other materials are
used, including germanium, gallium arsenide,
and silicon carbide. A pure semiconductor is
often called an “intrinsic” semiconductor. The
electronic properties and the conductivity of a
semiconductor can be changed in a controlled
manner by adding very small quantities of other
elements, called “dopants”, to the intrinsic
material. In crystalline silicon typically this is
achieved by adding impurities of boron or
phosphorus to the melt and then allowing the
melt to solidify into the crystal. This process is
called "doping".[1]

A semiconductor is a material with electrical
conductivity due to electron flow (as opposed to
ionic conductivity) intermediate in magnitude
between that of a conductor and an insulator.
This means a conductivity roughly in the range of
103 to 10−8 siemens per centimeter.
Semiconductor materials are the foundation of
modern electronics, including radio, computers,
telephones, and many other devices. Such
devices include transistors, solar cells, many
kinds of diodes including the light-emitting diode,
the silicon controlled rectifier, and digital and
analog integrated circuits. Similarly,
semiconductor solar photovoltaic panels directly
convert light energy into electrical energy. In a
metallic conductor, current is carried by the flow
of electrons. In semiconductors, current is often
schematized as being carried either by the flow of
electrons or by the flow of positively charged
" holes" in the electron structure of the material.
Actually, however, in both cases only electron
movements are involved.
Common semiconducting materials are
crystalline solids, but amorphous and liquid
semiconductors are known. These include
hydrogenated amorphous silicon and mixtures of
arsenic, selenium and tellurium in a variety of
proportions. Such compounds share with better
known semiconductors intermediate conductivity
and a rapid variation of conductivity with
temperature, as well as occasional negative
resistance. Such disordered materials lack the
rigid crystalline structure of conventional
semiconductors such as silicon and are generally
used in thin film structures, which are less
demanding for as concerns the electronic quality
of the material and thus are relatively insensitive
to impurities and radiation damage. Organic
semiconductors, that is, organic materials with
properties resembling conventional
semiconductors, are also known.
Silicon is used to create most semiconductors
commercially. Dozens of other materials are
used, including germanium, gallium arsenide,
and silicon carbide. A pure semiconductor is
often called an “intrinsic” semiconductor. The
electronic properties and the conductivity of a
semiconductor can be changed in a controlled
manner by adding very small quantities of other
elements, called “dopants”, to the intrinsic
material. In crystalline silicon typically this is
achieved by adding impurities of boron or
phosphorus to the melt and then allowing the
melt to solidify into the crystal. This process is
called "doping".[1]

Phy num

One heater uses 410 W of power
when connected by itself to a battery.
Another heater uses 260 W of power
when connected by itself to the same
battery. How much total power do
the heaters use when they are both
connected in series across the
battery?

Pentagon

Pentagon is going 2 Organize science fair