Question

A semiconductor has equal electron and hole concentration of $4\times 10^8{m}^{-3}$. On doping with a certain impurity, the electron concentration increases to $3.2\times 10^9{m}^{-3}$, then the new hole concentration of the semiconductor is ________$\times 10^6{m}^{-3}$.

Answer 1

Answer: 50

$n_e{n}_h=n_i^2$
$\therefore 3.2\times 10^9\times n_h=16\times 10^{16}$
$\therefore n_h=50\times 10^6{m}^{-3}$