Indium arsenide, InAs, or indium monoarsenide, is a narrow-bandgap

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way ...

composed of indium and

arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, b ...

. It has the appearance of grey

cubic crystal In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals. There are three main varieties ...

s with a melting point of 942 °C. Indium arsenide is similar in properties to

gallium arsenide Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated c ...

and is a direct bandgap material, with a bandgap of 0.35 eV at room temperature. Indium arsenide is used for construction of infrared detectors, for the

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tr ...

range of 1–3.8 µm. The detectors are usually

photovoltaic Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially ...

photodiodes. 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. InAs is well known for its high electron mobility and narrow energy bandgap. It is widely used as

terahertz radiation Terahertz radiation – also known as submillimeter radiation, terahertz waves, tremendously high frequency (THF), T-rays, T-waves, T-light, T-lux or THz – consists of electromagnetic waves within the ITU-designated band of fr ...

source as it is a strong photo-Dember emitter. The optoelectronic properties and phonon vibrations are slightly changed under the effect of temperature over the range form 0 K to 500 K., while the change is quite significant under the effect of pressure, for example InAs converted from a direct band gap semiconductor to an indirect band gap semiconductor.

Ternary and quaternary compounds

Indium arsenide is sometimes used together with

indium phosphide Indium phosphide (InP) is a binary semiconductor composed of indium and phosphorus. It has a face-centered cubic (" zincblende") crystal structure, identical to that of GaAs and most of the III-V semiconductors. Manufacturing Indium phosphide ...

. Alloyed with gallium arsenide it forms the ternary semiconductor

indium gallium arsenide Indium gallium arsenide (InGaAs) (alternatively gallium indium arsenide, GaInAs) is a ternary alloy ( chemical compound) of indium arsenide (InAs) and gallium arsenide (GaAs). Indium and gallium are ( group III) elements of the periodic table w ...

(In_xGa_(1-x)As), a material with band gap dependent on In/Ga ratio. Indium arsenide is sometimes alloyed with

and Indium antimonide to create a quaternary alloy with a range of band gaps that depend on the different concentration ratios of its components (InP, InAs and InSb), such quaternary alloys was under extensive theoretical studies to study the effect of pressure and temperature on its properties. Quantum dots can be formed in a monolayer of indium arsenide on

or gallium arsenide. The mismatches of lattice constants 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.

References

External links

Ioffe institute data archive entry

National Compound Semiconductor Roadmap
entry for InAs at ONR web site {{Semiconductor laser Arsenides Indium compounds III-V semiconductors III-V compounds Zincblende crystal structure