AlGaSbbased

AlGaSb-based materials are semiconductors formed from aluminum, gallium, and antimony, with the general composition AlxGa1−xSb, where 0 ≤ x ≤ 1. They belong to the III–V family and crystallize in the zinc blende structure in bulk form and in epitaxial layers. Varying x allows tuning of the lattice constant and electronic band structure. Growth is commonly performed by molecular beam epitaxy (MBE) or metal-organic chemical vapor deposition (MOCVD) on GaSb- or InAs-based substrates, often with excess antimony to maintain stoichiometry. Strain management, using buffer layers, is frequently required when integrating with mismatched substrates.

The band gap of AlGaSb alloys can be adjusted from the narrow gap of GaSb toward larger gaps as aluminum content increases, enabling infrared responsiveness across portions of the mid- to long-wavelength range. The material often forms well into heterostructures such as quantum wells and quantum cascade-like devices, where discontinuities in band alignment confine carriers. The high carrier mobility of these III–V antimonide compounds supports high-speed electronics and infrared photodetection.

Applications and devices: AlGaSb-based structures are used in infrared detectors and emitters, including photodiodes, laser diodes, and interband or intersubband devices aimed at MWIR and LWIR wavelengths. They are commonly integrated with GaSb- or InAs-based components to create heterostructures for optimized band alignment and thermal performance.

Challenges: material quality is sensitive to stoichiometry, surface oxidation, and growth conditions; achieving uniform aluminum incorporation and defect suppression remains an active area of research. Compatibility with available substrates and thermal management are important considerations in device design.