To get `n`-type doped semiconductor, impurity to be added to silicon should have the following number of valence electrons

Options

A. 2
B. 3
C. 4
D. 5

Answer

A

Explanation

The outer shell of Si have `3p^(2)` electrons, addition of impurity with 2 valence electrons leads to half - filled `3p^(3)` orbital and an extra electron which conducts electricity on passage of current through Si semiconductor. Since the current flowing in the semiconductor after doping is due to electron, it will be n-type semiconductor.