Si0.001Ge0.999

Si₀.₀₀₁Ge₀.₉₉₉ is a silicon-germanium alloy with extremely high germanium content (≥99.9%), representing the germanium-rich end of the SiGe semiconductor alloy system. This near-pure germanium material with trace silicon doping is primarily a research and specialized industrial compound, used where germanium's direct bandgap and high carrier mobility are exploited, while the silicon addition provides fine-tuning of lattice properties and doping behavior.