GaSbbased

GaSb-based refers to a family of semiconductors centered on gallium antimonide (GaSb). This family includes the binary GaSb and a range of alloy systems such as GaInSb, GaInAsSb, and AlGaSb, where indium, arsenic or aluminum content is varied to adjust the bandgap and lattice constant. These materials are direct-bandgap III–V semiconductors that can be engineered to cover the near- to mid-infrared spectrum.

At room temperature GaSb has a narrow bandgap around 0.726 eV, and alloy variants span wider or narrower gaps depending on composition. By mixing Ga, In, As and Sb in appropriate proportions, researchers can tune the bandgap to target wavelengths roughly in the 1 to 6 micrometers range. This makes GaSb-based materials well suited for infrared detectors and emitters, including photodiodes, laser diodes, and quantum well structures designed for mid-infrared applications.

Growth and fabrication commonly use molecular beam epitaxy or metal-organic chemical vapor deposition. Epitaxial layers are grown on GaSb substrates or on lattice-matched buffer layers on alternative substrates (for example GaAs with metamorphic buffers) to manage lattice mismatch. Device structures frequently employ heterojunctions and quantum wells in GaSb- and InGaSb-based systems, as well as GaSb/AlSb and related barriers for confinement.

Applications include infrared sensing, spectroscopy and free-space communications in the 2–5 micrometer range and beyond, as well as thermal imaging detectors and mid-infrared diode or edge-emitting lasers. GaSb-based materials are also explored for thermophotovoltaic energy conversion.

Challenges include achieving high material quality and defect control due to lattice mismatch, oxide formation and surface states. Processing requires specialized handling and passivation, and overall costs and substrate availability can be limiting factors for certain compositions.