Metalloid found in cell phones (along with at least 39 other metals and nonmetals). Tellurium is expected to find such use. Of the less often recognised metalloids, phosphorus, gallium (in particular) and selenium have semiconductor applications. Phosphorus is used in trace amounts as a dopant for n-type semiconductors. The commercial use of gallium compounds is dominated by semiconductor applications—in integrated circuits, cell phones, laser diodes, light-emitting diodes, photodetectors, and solar cells. Selenium is used in the production of solar cells and in high-energy surge protectors. Boron, silicon, germanium, antimony, and tellurium, as well as heavier metals and metalloids such as Sm,
Silicon-germanium Silicon-germanium SiGe ( or ), or silicon-germanium, is an alloy with any molar ratio of silicon and germanium, i.e. with a molecular formula of the form SiGe. It is commonly used as a semiconductor material in integrated circuits (ICs) for heterojunction bipolar transistors or as a strain-inducing layer for CMOS transistors. IBM introduced the technology into mainstream manufacturing in 1989. This relatively new technology offers opportunities in mixed-signal circuit and analog circuit IC design and manufacture. SiGe is also used as a thermoelectric material for high temperature applications (>700 K). The use of silicon-germanium as a semiconductor was championed by