Electric conduction in a semiconductor takes place due to

The net charge on an $N-$type semiconductor is

The hole and the free electron concentrations in a pure silicon at room temperature are given by $1.4 \times 10^{16} \ m^{-3}$ each under equilibrium. When it is doped with indium and the hole concentration is $n_{h} = 4 \times 10^{22} \ m^{-3}$,the electron concentration is

Suppose a pure $Si$ crystal has $5 \times 10^{28}$ atoms $m^{-3}$. It is doped by $1$ ppm concentration of pentavalent $As$. Calculate the number of holes. Given that $n_i = 1.5 \times 10^{16} m^{-3}$.

$A$ pure $Si$ crystal has $4 \times 10^{28}$ atoms per $m^3$. It is doped with $1 \text{ ppm}$ concentration of antimony. The number of free electrons available will be

In an extrinsic semiconductor,the number densities of holes and electrons are ${N_p}$ and ${N_e}$ respectively. Then: