Physics - Semiconductors Question with Solution | TestHub

When Ge specimen is doped with $\mathrm{Al}$, then concentration of acceptor atoms is also called concentration of holes. Using formula, $n_i^2=n_0{p}_0$, where $$\begin{array}{rl}{n}_i=& \text{ concentration of electron-hole pair }=10^{19}/{\mathrm{m}}^3\\ & n_0=\text{ concentration of electron }\\ & p_0=\text{ concentration of holes }=10^{21}\text{ atom }/{\mathrm{m}}^3\\ \Rightarrow & {\left(10^{19}\right)}^2=10^{21}\times n_0\Rightarrow n_0=10^{17}/{\mathrm{m}}^3.\end{array}$$