The following band-energy diagram represents:

In pure $Si$ at $300 \ K$,the concentration of electrons $(n_e)$ and holes $(n_h)$ is equal and is $1.5 \times 10^{16} \ m^{-3}$. If the concentration of holes $(n_h)$ increases to $3 \times 10^{22} \ m^{-3}$ after doping with Indium,calculate the concentration of electrons $(n_e)$ in the doped $Si$.

The charge carriers in a $p$-type semiconductor are

Indium impurity in germanium makes

$A$ donor impurity results in

At a temperature of $500 \ K$,the intrinsic electron number density $(n_e)$ and hole number density $(n_h)$ in a pure semiconductor are equal to $1.5 \times 10^{16} \ m^{-3}$. Now,by adding indium impurity,the hole density $(n_h)$ increases to $4.5 \times 10^{22} \ m^{-3}$. This doped semiconductor is: