Indium Phosphide (InP)

Commonly used as substrate for epitaxial InGaAs. Superior electron veloxity, used in high-power and high-frequency applications. Used in optoelectronics.

Indium arsenide (InAs)

Used for infrared detectors for 1â€"3.8 µm, cooled or uncooled. High electron mobility. InAs dots in InGaAs matrix can serve as quantum dots. Quantum dots may be formed from a monolayer of InAs on InP or GaAs. Strong  photo-Denber emitter, used as a terahertz radiation source.

Indium antimonide (Insb)

Used in infrared detectors and thermal imaging sensors, high quantum efficiency, low stability, require cooling, used in military long-range thermal imager systems. AlInSb-InSb-AlInSb structure used as quantum well. Very high electron mobility, electron velocity and ballistic length. Transistors can operate below 0.5V and above 200 GHz. Terahertz frequencies maybe achievable.

Gallium phosphide (GaP)

Used in early low to medium brightness cheap red/orange/green LEDs. Used standalone or with GaAsP. Transparent for yellow and red light, used as substrate for GaAsP red/yellow LEDs. Doped with S or Te for n-type, with Zn for p-type. Pure GaP emits green, nitrogen-doped GaP emits yellow-green, ZnO-doped GaP emits red.

Gallium antimonide (GaSb)

Used for infrared detectors and LEDs and thermophotovoltaics. Doped n with Te, p with Zn.

Gallium arsenide (GaAs)

second most common in use after silicon, commonly used as substrate for other III-V semiconductors, e.g. InGaAs and GaInNAs. Brittle. Lower hole mobility than Si, P-type CMOS transistors unfeasible. High impurity density, difficult to fabricate small structures. Used for near-IR LEDs, fast electronics, and high-efficiency solar cells. Very similar lattice constant to germanium, can be grown on germanium substrates.