Q 12-14-154JEE MainJEE Main 2021 (25 Jul, Shift 2)Easy
In a semiconductor, the number density of intrinsic charge carriers at $27^\circ$C is $1.5\times10^{16}$ m$^{-3}$. If the semiconductor is doped with an impurity atom, the hole density increases to $4.5\times10^{22}$ m$^{-3}$. The electron density in the doped semiconductor is ______ $\times10^9$ m$^{-3}$
Numerical value type. Enter your answer.
Answer: 5
$n_e n_h = n_i^2$:
$$n_e = \frac{(1.5\times10^{16})^2}{4.5\times10^{22}} = \frac{2.25\times10^{32}}{4.5\times10^{22}} = 5\times10^9\ \text{m}^{-3}$$
Solution by Sreeraj P, M.Sc Physics