silicon germanium (SiGe)
Silicon germanium(SiGe) is a compound semiconductor consisting of silicon( Si) and germanium( Ge) and belongs to the IV-IV compound semiconductors, since both chemical elements, silicon and germanium, are from the IV. main group of the periodic table.
Much faster transistors can be made from silicon-germanium than from conventional silicon. This means that active components for microwave technology and the fastest switching components for microelectronics can be produced from silicon-germanium, using the same production equipment as for silicon. The frequency range extends up to well above 60 GHz. However, unlike those made of gallium arsenide( GaAs) or indium phosphide( InP), compound semiconductors made of silicon germanium can only operate at low power levels and are limited in their voltage potential.
Silicon germanium can be used in photovoltaics; it absorbs wavelengths up to 1,600 nm.