Target Exam

CUET

Subject

Physics

Chapter

Semiconductors and Electronic Devices

Question:

In order to fabricate n-type semiconductor, the impurity elements used are

Options:

acceptor atoms like Aluminum, Indium.

donor atoms like Phosphorous, Arsenic.

carbon as it has four valence electrons.

semiconductor atoms like Silicon and Germanium.

Correct Answer:

donor atoms like Phosphorous, Arsenic.

Explanation:

The correct answer is Option (2) → donor atoms like Phosphorous, Arsenic.

In an n-type semiconductor, extra electrons are introduced to increase conduction. This is achieved by doping the semiconductor (Si or Ge) with pentavalent atoms (5 valence electrons) like Phosphorus or Arsenic. Four electrons form covalent bonds with the semiconductor lattice, leaving the fifth electron free to move and contribute to electrical conduction.