Question

Observe the given figure carefully and fill in the blanks choosing the correct option.

• A. (p) - Perfect crystal; (q) - $p-$type semiconductor; (r) - $n-$type semiconductor
• B. (p) - Doped crystal; (q) - $n-$type semiconductor; (r) - $p-$type semiconductor
• C. (p) - Perfect crystal; (q) - $n-$type semiconductor; (r) - $p-$type semiconductor
• D. (p) - $n-$type semiconductor; (q) - Perfect crystal; (r) - Perfect crystal

Answer 1

The correct option is C (p) - Perfect crystal; (q) - $n-$type semiconductor; (r) - $p-$type semiconductor

In n-type semiconductor, $Si$ and $Ge$ are doped with group 15 elements. Since group 15 elements have five electrons in valence shell which is one more than $Si$ or $Ge$ i.e. four electrons. So, the material becomes electron rich and it becomes n- type.

In p-type semiconductor, $Si$ and $Ge$ are doped with group 13 elements. Since group 13 elements have three electrons in valence shell which is one less than $Si$ or $Ge$ i.e. four electrons. So, the material becomes electron deficit and it becomes p- type.