Aluminium indium arsenide, also indium aluminium arsenide or AlInAs (
Alx In1−x As), is a ternary
III-V semiconductor compound with very nearly the same
lattice constant as
InGaAs, but a larger
bandgap
In solid-state physics and solid-state chemistry, a band gap, also called a bandgap or energy gap, is an energy range in a solid where no electronic states exist. In graphs of the electronic band structure of solids, the band gap refers to the ...
. It can be considered as an alloy between
aluminium arsenide (AlAs) and
indium arsenide
Indium arsenide, InAs, or indium monoarsenide, is a narrow-bandgap semiconductor composed of indium and arsenic. It has the appearance of grey cubic crystals with a melting point of 942 °C.
Indium arsenide is similar in properties to gallium ars ...
(InAs). AlInAs refers generally to any composition of the alloy.
Structural and Electronic Properties
The
bandgap
In solid-state physics and solid-state chemistry, a band gap, also called a bandgap or energy gap, is an energy range in a solid where no electronic states exist. In graphs of the electronic band structure of solids, the band gap refers to the ...
and
lattice constant of AlInAs alloys are between those of pure
AlAs (a = 0.566 nm, E
g = 2.16 eV) and
InAs (a = 0.606 nm, E
g = 0.42 eV).
At a composition of approximately x = 0.64, the band gap transitions between direct and indirect.
AlInAs shares the same
zincblende crystal structure as AlAs and InAs.
Applications
Aluminium indium arsenide is used e.g. as a buffer layer in
metamorphic HEMT transistors, where it serves to adjust the lattice constant differences between the
GaAs substrate and the
GaInAs channel. It can be also used to form alternate layers with
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 13 element, group III elements of the peri ...
, which act as
quantum wells; these structures are used in, e.g., broadband
quantum cascade lasers.
Safety and toxicity aspects
The toxicology of AlInAs has not been fully investigated. The dust is an irritant to skin, eyes and lungs. The environment, health and safety aspects of aluminium indium arsenide sources (such as
trimethylindium and
arsine) and industrial hygiene monitoring studies of standard
MOVPE sources have been reported recently in a review.
References
{{DEFAULTSORT:Aluminium Indium Arsenide
III-V semiconductors
III-V compounds
Arsenides
Aluminium compounds
Indium compounds
Zincblende crystal structure