When added an impurity into the silicon which one of the following produces `n`-type of semiconductors?

Options

A. Iron
B. Magnesium
C. Phosphorus
D. Aluminium

Answer

C

Explanation

Silicon has `4` valence electrons, when phosphorous with `5` valence electrons in its outermost orbit is added, then four of the five valence electrons of the impurity atom from covalent bonds with each valence electrons becomes free to move in the crystal. As the electrons are charge carriers they are called `n`-type.