When the conductivity of a semiconductor is only due to the breaking of the covalent bonds,the semiconductor is called

Which one of the following statements is true? $A$ p-type semiconductor is doped with

What is the number density of donor atoms which must be added to a pure germanium semiconductor to make an $n$-type semiconductor of conductivity $6.4 \ \Omega^{-1} \ cm^{-1}$? The mobility of electrons in $n$-type germanium is $4 \times 10^3 \ cm^2 \ V^{-1} \ s^{-1}$. Neglect the contribution of holes to conductivity.

The typical ionisation energy of a donor in silicon is.....$eV$

If $n_e$ and $n_h$ are electron and hole concentrations in an extrinsic semiconductor and $n_i$ is the intrinsic carrier concentration, then:

$A$ semiconductor doped with a donor impurity is