Chemistry - Solid State Question with Solution | TestHub

An n-type semiconductor is formed when an intrinsic semiconductor (like Silicon or Germanium) is doped with a pentavalent impurity (Group 15 elements such as Phosphorus, Arsenic, or Antimony).

Phosphorus is a pentavalent impurity. When Silicon is doped with Phosphorus, four of its five valence electrons form covalent bonds with the surrounding Silicon atoms, while the fifth electron remains loosely bound and is available for conduction, resulting in an n-type semiconductor.

Boron and Aluminium are trivalent impurities (Group 13 elements). Doping Silicon or Germanium with them creates holes, resulting in a p-type semiconductor.

Answer: Silicon doped with phosphorous