GaAs

Gallium Arsenide (GaAs) is a III-V direct bandgap semiconductor compound formed from gallium and arsenic, widely recognized as a foundational material in optoelectronics and high-frequency electronics. It is the primary material choice for photovoltaic cells in space applications, laser diodes, and integrated circuits operating at microwave and millimeter-wave frequencies where its superior electron mobility and direct bandgap outperform silicon. Engineers select GaAs over conventional semiconductors when high radiation tolerance, efficient light emission/detection, or extreme frequency performance is required—making it indispensable in satellite power systems, fiber-optic communications, and defense/aerospace RF applications, though its higher cost and brittleness limit use to applications where these advantages justify the trade-off.