Common semiconductor materials include silicon, germanium and gallium arsenide. Boron, silicon, germanium, tellurium are semiconductors. Germanium or Indium gallium arsenide (InGaAs) detectors are commonly used. Boron is a useful dopant for such semiconductors as silicon, germanium, and silicon carbide. Semiconductor detectors utilise the semiconducting element germanium. Aluminium, gallium, germanium, carbon, oxygen and nitrogen are alpha stabilizers. Secondary products include lead, silver, gold, molybdenum, germanium, indium and cadmium. Gallium, indium, thallium, germanium, and tin are specifically mentioned in this context. The core is depleted in germanium and gallium. An argon atmosphere is also used for growing crystals of silicon and germanium. Several germanium and silicon models are available. Gamma ray reduction techniques are especially useful for small lithium-doped germanium (Ge(Li)) detectors. Pyrite detectors can be as sensitive as a modern 1N34A germanium diode detector. Graphene can absorb a broader range of wavelengths than germanium. The common oxide of germanium (GeO) is amphoteric.