Gallium is a rare, low-abundance dispersed metal with an extremely low melting point; it almost never forms its own ore and is mainly extracted as a by-product from the Bayer liquor of alumina refining, yet it underlies the entire compound-semiconductor industry. Its largest use is in gallium arsenide (GaAs) and gallium nitride (GaN) wafers: GaAs powers RF power amplifiers, cellular base stations and satellite communications chips, with high-frequency performance superior to silicon, while GaN enables fast chargers, 5G base stations and lidar, with power density and efficiency far exceeding conventional silicon devices. In LEDs, GaN-based blue chips are the light-emitting core of white LEDs, which together with phosphors deliver energy-efficient lighting and displays. In solar power, multi-junction GaAs cells are used on satellites and space probes and lead all photovoltaic technologies in conversion efficiency. Gallium is also used in infrared optical lenses, low-melting alloys and nuclear-medicine tracers—a classic example of a strategic 'bottleneck' metal consumed in small quantities.
Gallium arsenide (GaAs) is the flagship material of second-generation compound semiconductors, used in RF devices, laser diodes and GaAs solar cells, and is irreplaceable in satellites, mobile phones and optical communications. Gallium nitride (GaN) is a wide-bandgap semiconductor that forms the core material of blue LEDs, fast-charging power devices and 5G RF amplifiers, with demand surging in recent years as GaN chargers and base-station chips scale up. Gallium oxide (Ga2O3) is an emerging ultra-wide-bandgap oxide semiconductor drawing strong interest for deep-UV solar-blind detectors and power devices. Indium gallium arsenide (InGaAs) is an important ternary compound semiconductor used in detectors and lasers for fiber-optic communications and as the photosensitive surface of infrared night-vision imagers, making it a key material for optical communications and infrared equipment.
