Question

In a p-type Si sample, the hole concentration is $2.25\times {10}^{15}/c{m}^3$. The intrinsic carrier concentration is $1.5\times {10}^{10}/c{m}^3$, the electron concentration is

Answer 1

Ans :
By Mass Action Law
$n.p=n_i^2$
Where, $n=$ electron concentration
$p=$ hole concentration
$n_i$ = intrinsic carrier concentration
$p=2.25\times {10}^{15}/c{m}^3$
$n_i=1.5\times {10}^{15}/c{m}^3$
$n=\frac{n_i^2}{p}=\frac{(1.5\times {10}^{10}{)}^2}{2.25\times {10}^{15}}=\frac{2.25\times {10}^{20}}{2.25\times {10}^{15}}$
$n={10}^5/c{m}^3$