An $n$-type and $p$-type semiconductor can be obtained by respectively doping pure silicon with

The following band-energy diagram represents:

$A$ 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,$n_i = 1 \times 10^{16} \text{ m}^{-3}$).

$A$ silicon specimen is made into a $P$-type semiconductor by doping,on an average,one Indium atom per $5 \times 10^7$ silicon atoms. If the number density of atoms in the silicon specimen is $5 \times 10^{28} \text{ atoms}/m^3$,then the number of acceptor atoms in silicon per cubic centimetre will be:

$A$ crystal of intrinsic silicon at room temperature has a carrier concentration of $1.6 \times 10^{16} / m^3$. If the donor concentration level is $4.8 \times 10^{20} / m^3$, then the concentration of holes in the semiconductor is

For pure $Ge$,the intrinsic carrier density is $10^{19} \ m^{-3}$. If donor impurity is added with a density of $10^{23} \ m^{-3}$,what will be the hole density (in $m^{-3}$)?