The mobility of free electrons is greater than that of free holes because

In a pure silicon $(n_i = 10^{16}/m^3)$ crystal at $300\, K$,$10^{21}$ atoms of phosphorus are added per cubic meter. The new hole concentration will be

An $N-$type and $P-$type silicon can be obtained by doping pure silicon with

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

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

What are $n$-type and $p$-type semiconductors? Name the majority and minority charge carriers in each.