What groups of elements are doped into semiconductors to create impurities?

Doping in semiconductors involves introducing impurities to modify their electrical properties. The correct answer highlights two primary groups of elements used in this process: donor and acceptor.

Donor impurities are typically elements from group V of the periodic table, such as phosphorus or arsenic, which have five valence electrons. When these elements are introduced into a silicon lattice (which has four valence electrons), they provide extra electrons. This process results in n-type semiconductors, characterized by an increase in negatively charged carriers (electrons).

Conversely, acceptor impurities usually come from group III elements, like boron or aluminum, which have three valence electrons. When these elements replace some silicon atoms, they create "holes" or positively charged carriers since one electron is missing from the silicon lattice. This introduces p-type semiconductors where the charge carriers are holes.

Understanding donor and acceptor types is essential in semiconductor physics because it defines how electrical conduction occurs in materials, playing a key role in the operation of various electronic devices, such as diodes and transistors. This concept forms a fundamental part of semiconductor theory and is critical for technicians working with electronic equipment.