In an $n$-type semiconductor, the Fermi energy level lies

If a semiconductor has an intrinsic carrier concentration of $1.41 \times 10^{16} \, m^{-3}$,when doped with $10^{21} \, m^{-3}$ phosphorus,then the concentration of holes at room temperature will be

$A$ silicon sample is made into a $p$-type semiconductor by doping. Indium atoms are added at a rate of one atom per $5 \times 10^7$ silicon atoms. If the number density of silicon is $5 \times 10^{28} \text{ atoms/m}^3$,calculate the number density of acceptor atoms per $\text{cm}^3$.

Explain the recombination coefficient of an intrinsic semiconductor and derive the relation $n_i^2 = n_e n_h$.

The addition of antimony atoms to a sample of intrinsic germanium transforms it into a material which is:

Out of the following impurities, which impurity is not a trivalent?