Is gallium a semiconductor

to directory mode


The main area of ‚Äč‚Äčapplication for the elements gallium and indium (98% of production) is semiconductor technology, e.g. as a material for doping silicon (p-doping) or in the manufacture of A (III) -B (V) semiconductors. Binary compounds such as gallium arsenide, GaAs or -phosphide, GaP, indium phosphide, InP, -arsenide, InAs or -antimonide, InSb, but also combinations of three, e.g. GaAs are typical1-xPx or AlxGa1-xAs. The gallium and indium-based semiconductor materials are used in numerous optoelectronic components (LEDs), lasers, diodes, photodetectors, solar cells, etc.).

65% of today's total indium production goes into the production of indium tin oxide. This is indium (III) oxide, which is doped with a small amount (approx. 10%) of tin (IV) oxide and thus has transparent and semiconducting properties. The indium tin oxide is used in liquid crystal screens (LCDs), touch screens and solar cells.

Due to its low melting point and high boiling point and the resulting large liquid range, elemental gallium is used as a barrier medium for gases or as a measuring liquid for thermometer fillings, especially in the high temperature range up to 1200. Certain alloys of gallium with iron, magnesium or some rare earth metals result in magnetic materials. In addition, there are gallium compounds that have the property of superconductivity.

Indium and thallium are also of certain importance as alloy additives to bearing metals (alloys for the manufacture of axle bearings for machine shafts) and steel to increase corrosion resistance and hardness. Indium is relatively resistant to acids and alkalis and is therefore used in the form of thin coatings as corrosion protection (Indium plating). In nuclear reactors, the metal is used for brake rods because of its high neutron capture cross-section. Thallium amalgam is used as a filling for cold thermometers. Thallium bromides and iodides are used as so-called optical windows in infrared spectroscopy.

Known, but banned for a long time in Germany because of its extreme toxicity for humans, the use of thallium compounds as rat and mouse poison as well as pesticides is (Rodenticide).