Indium arsenide, InAs, or indium monoarsenide, is a semiconductor material, a semiconductor

Semiconductor

A semiconductor is a material with electrical conductivity due to electron flow 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...

 composed of indium

Indium

Indium is a chemical element with the symbol In and atomic number 49. This rare, very soft, malleable and easily fusible post-transition metal is chemically similar to gallium and thallium, and shows the intermediate properties between these two...

 and arsenic

Arsenic

Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...

. It has the appearance of grey cubic crystals with a melting point of 942 °C.

Indium arsenide is used for construction of infrared detector

Infrared detector

An infrared detector is a photodetector that reacts to infrared radiation. The two main types of detectors are thermal and photonic.The thermal effects of the incident IR radiation can be followed through many temperature dependent phenomena....

s, for the wavelength

Wavelength

In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...

 range of 1–3.8 µm. The detectors are usually photovoltaic photodiode

Photodiode

A photodiode is a type of photodetector capable of converting light into either current or voltage, depending upon the mode of operation.The common, traditional solar cell used to generateelectric solar power is a large area photodiode....

s. Cryogenically cooled detectors have lower noise, but InAs detectors can be used in higher-power applications at room temperature as well. Indium arsenide is also used for making of diode lasers.

Indium arsenide is similar to gallium arsenide and is a direct bandgap material.

Indium arsenide is sometimes used together with indium phosphide. Alloyed with gallium arsenide it forms indium gallium arsenide

Indium gallium arsenide

Indium gallium arsenide is a semiconductor composed of indium, gallium and arsenic. It is used in high-power and high-frequency electronics because of its superior electron velocity with respect to the more common semiconductors silicon and gallium arsenide. InGaAs bandgap also makes it the...

 - a material with band gap

Band gap

In solid state physics, a band gap, also called an energy gap or bandgap, is an energy range in a solid where no electron states can exist. In graphs of the electronic band structure of solids, the band gap generally refers to the energy difference between the top of the valence band and the...

 dependent on In/Ga ratio, a method principally similar to alloying indium nitride with gallium nitride to yield indium gallium nitride

Indium gallium nitride

Indium gallium nitride is a semiconductor material made of a mix of gallium nitride and indium nitride . It is a ternary group III/group V direct bandgap semiconductor. Its bandgap can be tuned by varying the amount of indium in the alloy...

.

InAs is well known for its high electron mobility and narrow energy bandgap. It is widely used as terahertz radiation source as it is a strong Photo-dember

Photo-dember

In semiconductor physics, the photo-Dember effect consists in the formation of a charge dipole in the vicinity of a semiconductor surface after ultra-fast photo-generation of charge carriers...

 emitter.

Quantum dot

Quantum dot

A quantum dot is a portion of matter whose excitons are confined in all three spatial dimensions. Consequently, such materials have electronic properties intermediate between those of bulk semiconductors and those of discrete molecules. They were discovered at the beginning of the 1980s by Alexei...

s can be formed in a monolayer of indium arsenide on indium phosphide or gallium arsenide. The mismatches of lattice constant

Lattice constant

The lattice constant [or lattice parameter] refers to the constant distance between unit cells in a crystal lattice. Lattices in three dimensions generally have three lattice constants, referred to as a, b, and c. However, in the special case of cubic crystal structures, all of the constants are...

s of the materials create tensions in the surface layer, which in turn leads to formation of the quantum dots. Quantum dots can also be formed in indium gallium arsenide, as indium arsenide dots sitting in the gallium arsenide matrix.

External links

• Ioffe institute data archive entry
• National Compound Semiconductor Roadmap entry for InAs at ONR web site