AlInSb

AlInSb is a ternary III-V semiconductor alloy consisting of aluminum, indium, and antimony with the formula AlxIn1−xSb, where x denotes the aluminum content. Like other III-V Sb-based compounds, it adopts a zinc blende crystal structure in bulk and in epitaxial films. The material’s properties can be tuned by composition and temperature, making it part of a broader family of Sb-containing alloys used in infrared optoelectronics.

The material offers a tunable bandgap that ranges from the near-zero gap of InSb toward the wider gap of AlSb as x increases. This direct bandgap and the ability to engineer band offsets make AlInSb suitable for infrared optoelectronic applications. The lattice constant also varies with composition, allowing partial lattice matching to common substrates such as InSb, GaSb, or Al-containing Sb substrates depending on x, with growth typically by molecular beam epitaxy or metal-organic chemical vapor deposition.

Applications include infrared detectors and focal plane arrays in the 1–5 μm range, avalanche or photodiode structures, and quantum-well or barrier-confinement devices. AlInSb is often used in heterostructures with InAs, GaSb, or AlSb to form type I or type II band alignments for detectors and lasers. Material quality depends on precise control of stoichiometry and antimony overpressure, as Sb-rich or Sb-deficient growth can introduce defects.

See also InSb, AlSb, GaSb, III–V semiconductors.