InAs

Indium arsenide (InAs) is a binary compound semiconductor in the III-V family. It crystallizes in the zinc blende structure and is typically produced as epitaxial layers using methods such as molecular beam epitaxy (MBE) or metal-organic chemical vapor deposition (MOCVD). Growth often employs substrates like GaSb, GaAs, or InP with buffer layers to manage lattice mismatch.

InAs has a narrow direct bandgap of about 0.35 eV at room temperature, corresponding to infrared wavelengths near 3.5 micrometers. This small bandgap enables efficient infrared emission and detection and makes InAs a key material for mid-infrared optoelectronic devices. The material also features a light effective electron mass and high electron mobility, contributing to high-speed electronic devices such as high-electron-mobility transistors (HEMTs) and other heterostructures.

A notable property of InAs is a surface electron accumulation layer, arising from the alignment of its Fermi level with the conduction band. This surface behavior influences contact resistance, surface states, and device design, particularly for sensors and nanoscale electronics.

InAs is widely used in infrared sensing and photodetection, often in heterostructures with GaSb, AlSb, or InP-based compounds. These combinations enable various infrared photodetectors, quantum wells, and integrated optoelectronic devices. Safety considerations are important, as arsenic-containing compounds are toxic and require appropriate handling and disposal in controlled facilities.