Question

$\text{An n-type silicon sample has diffusion co-efficient of}\text{electrons 120 cm}{}^2\text{/sec and carrier life time of electron}\text{is 30 psec. Then the diffusion length of the sample}\left(L_n\right)\text{is}$

Answer 1

Ans : (a)

$\text{Given, diffusion co-efficient of electrons}{D}_n=120c{m}^2/sec\text{Carrier life time of electron,}{\tau }_n=30psec\text{Diffusion length,}{L}_n=\sqrt{D_n{\tau }_n}=\sqrt{120\times 30\times {10}^{-12}}{L}_n=60\times {10}^{-6}cm{L}_n=0.6\mu m$