Gallium arsenide (GaAs) is a gallium compound with arsenic, represented by the chemical formula GaAs, and is widely used as a material for semiconductor devices. In the semiconductor field the colloquial abbreviation “GaAs” is commonly used.

Compared to silicon, it is more expensive and more difficult to process, which are its disadvantages. However, it offers high-speed operation and consumes only approximately 1/3 of the power, making it well suited for miniaturization.

In recent years, thanks to advances in processing technology, GaAs devices have become more affordable, and they are now widely used—particularly in applications that require compact size and high-frequency performance, such as mobile phones, as well as in LED and laser applications.

GaSb (gallium antimonide) is a single crystal grown using a specialized LEC method, and is used in infrared detectors, infrared light-emitting diodes (LEDs), lasers, transistors, thermophotovoltaic systems, among others.

Furthermore, III–V compound semiconductors, represented by gallium antimonide (GaSb), are direct bandgap semiconductors. Compared to silicon (Si) based semiconductors, they have a smaller bandgap and can convert electromagnetic waves in the near-infrared region (wavelengths of 0.8 μm to 2.2 μm) into electrical power.

As for GaSb-based solar cells, despite the significant technical challenges, research is also being conducted on II–VI epitaxial layers grown by MBE on GaSb substrates.

InSb (indium antimonide) single crystal is a III–V compound material with a zinc blende structure.

InSb is a narrow direct bandgap semiconductor with a bandgap of 0.17 eV at room temperature, and it is mainly used in infrared detection devices such as infrared thermography and thermal imaging cameras, infrared-guided missiles, as well as in Hall sensors and magnetoresistive devices.