Physics / mechanism
GaAs is a III-V compound semiconductor with a direct bandgap of 1.42 eV and electron mobility ~8,500 cm²/V·s — roughly 6× silicon. Direct bandgap enables efficient radiative recombination, making it native to optoelectronics: lasers, LEDs, photodetectors, solar cells. High electron mobility drives RF/microwave performance; GaAs pHEMTs dominate 4G/5G front-end modules above ~6 GHz. Substrate quality is mature (6-inch semi-insulating wafers standard); epitaxy via MBE or MOCVD. Key fabs: WIN Semiconductors, AWSC, Qorvo, Skyworks. Breakdown field ~4× silicon; poor thermal conductivity (~46 W/m·K) limits power density. Not a platform for logic at scale.
Competitive landscape
| Material | Electron mobility | Bandgap type | Thermal conductivity | Typical application |
|---|---|---|---|---|
| GaAs | ~8,500 cm²/V·s | Direct | 46 W/m·K | RF FEMs, VCSELs, solar |
| GaN | ~2,000 cm²/V·s | Direct | 130 W/m·K | Power, mmWave PA |
| InP | ~5,400 cm²/V·s | Direct | 68 W/m·K | >100 GHz, photonics PICs |
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.