Dopanti

Dopanti, plural of dopante in Italian, are impurities introduced deliberately into a material to alter its physical properties without drastically changing its composition. The most prominent use is in semiconductors, where dopants create free charge carriers that control electrical conductivity. They come from donor elements (n-type) that supply electrons, or acceptor elements (p-type) that create holes. In silicon, common n-type dopants include phosphorus, arsenic, and antimony; p-type dopants include boron, aluminum, and gallium. Doping shifts the Fermi level and forms charge-carrier populations that enable electronic devices such as diodes and transistors. Activation of dopants typically requires annealing after implantation or diffusion.

In other materials, dopants adjust ionic conductivity, optical properties, or mechanical behavior. Doping zirconia with yttria stabilizes its cubic phase and creates oxide ion conduction, used in solid-oxide fuel cells. In glasses and optical fibers, dopants such as rare-earth ions alter refractive index and luminescence. In polymers, dopants can modify conductivity or charge transport.

Manufacturing considerations include control of dopant concentration, distribution, and activation, as well as diffusion and clustering. Techniques to introduce dopants include diffusion, ion implantation, or chemical routes, followed by thermal treatment to activate dopants and repair damage. Characterization methods such as SIMS, X-ray diffraction, or electrical measurements assess dopant profiles and their effects.

The term is used primarily in Italian-speaking contexts but is parallel to the broader concept of doping in materials science. Dopanti play a central role in electronics, energy devices, and advanced materials.