Extremely pure samples of `Ge` and `Si` are non`-`conductors, but their conductivity increases suddenly on introducting `…………………….` in their crystal lattice

Options

A. arsenic
B. boron
C. both `(a)` and `(b)`
D. none of these

Answer

c

Explanation

Doping of elements of group `14(Ge ` and `Si)` with group `15 (As)` elements produces excess of electrons and show `n-` type conduction, the symbol `n` indicating flow of negative charge in them. Doping of elements of group `14(Ge` and `Si)` with group `13(B)` elements produces hole `(` electron deficiency `)` in the crystal and shows `p-`type conduction, the symbol `p` indicating flow of positive charge.