Write the difference between intrinsic and extrinsic semiconductors.

Holes are charge carriers in

When a semiconductor is doped with donor impurity,

In a semiconductor,the number density of intrinsic charge carriers at $27^{\circ} \text{C}$ is $1.5 \times 10^{16} \, \text{m}^{-3}$. If the semiconductor is doped with impurity atoms,the hole density increases to $4.5 \times 10^{22} \, \text{m}^{-3}$. The electron density in the doped semiconductor is $..... \times 10^{9} \, \text{m}^{-3}$.

What is the conductivity of a pure silicon crystal at $300 \ K$? The number of electron-hole pairs per $cm^3$ is $1.072 \times 10^{10}$. Given $\mu_n = 1350 \ cm^2/V \cdot s$ and $\mu_p = 480 \ cm^2/V \cdot s$.

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