The process of adding impurities to a pure semiconductor is called

In a $P$-type semiconductor,the energy level formed in the forbidden gap near the valence band is called ...

$A$ pure semiconductor crystal has $8 \times 10^{28} \text{ atoms/m}^3$. It is doped with a $2 \text{ ppm}$ concentration of pentavalent atoms. The number of holes formed in the semiconductor crystal is (Intrinsic carrier concentration,$n_i = 1 \times 10^{16} \text{ m}^{-3}$).

In a sample of pure silicon, $10^{13} \text{ atoms/cm}^3$ of phosphorus is added. If all donor atoms are active and the electron mobility is $1200 \text{ cm}^2/\text{V}\cdot\text{s}$, what will be the resistivity at $20^\circ\text{C}$ in $\Omega\cdot\text{cm}$?

For an intrinsic semiconductor,where $n_{h}$ and $n_{e}$ are the number of holes per unit volume and the number of electrons per unit volume respectively,which of the following relations holds true?

The density of an electron-hole pair in a pure germanium is $3 \times 10^{16} \ m^{-3}$ at room temperature. On doping with aluminium,the hole density increases to $4.5 \times 10^{22} \ m^{-3}$. Now,the electron density (in $m^{-3}$) in doped germanium is: