A semiconductor of `Ge` can be made `p`-type by adding

Options

A. trivalent impurity
B. tetravalent impurity
C. pentavalent impurity
D. divalent impurity

Answer

1

Explanation

Electron -deficit `Ge` is called `p-type` semiconductor when `Ge` is doped with trivalent impurity (Froup `13` elements) like `B` the `Ge` atoms of some lattice sites are displaced by those of `B`. Now as Group `13` elements have only three valence electrons ,they can form three covalen tbonds with the neighbouring `Ge` atoms.Thus a hole is created at the site where fourth electron is missing.This is called electron hole or electron vacancy.