Si0.109Ge0.891

Si₀.₁₀₉Ge₀.₈₉₁ is a silicon-germanium alloy heavily weighted toward germanium, belonging to the IV-IV semiconductor family used in high-frequency and optoelectronic device research. This composition sits in a technologically important region for heterojunction bipolar transistors (HBTs) and integrated photonic applications where the germanium-rich character provides bandgap engineering advantages. The alloy is notable for enabling higher carrier mobility and lower operating voltages compared to pure silicon, making it attractive for next-generation RF/microwave circuits and emerging infrared detector technologies, though it remains primarily in research and specialized production rather than mass-market applications.