Physics - Semiconductors Question with Solution | TestHub

The conductivity of a semiconductor is given by $\sigma =n_{e}e{\mu }_e+n_{h}e{\mu }_h$ where $n_e$ and $n_h$ = number of electrons and holes per unit volume and ${\mu }_{\mathrm{e}}$ and ${\mu }_{\mathrm{h}}=$ mobility of electrons and holes. When impurity atoms are added in a semiconductor, then the concentration of holes and electrons increases. So, the conductivity Increases and hence the resistivity $\left(\rho =\frac{1}{\sigma }\right)$ of semiconductors decreases.