Question

Calculate the recombination rate if the excess carrier concentration is 1014cm-3 and the carrier lifetime is 1usec. (a) 108 (b) 1010 (c) 1020 (d) 1014

Answer 1

Answer:

$10^{20}\frac{cm^{-3}}{sec}$

Explanation:

The recombination rate is denoted by R it is the ratio of excess carrier concentration and life time

The recombination rate R is given by $R=\frac{\Delta n}{\tau _n}$

We have given excess carrier concentration = $10^{14}cm^-3$

Life time $\tau _n=10^{-6}sec$

So recombination rate $R=\frac{\Delta n}{\tau _n}=\frac{10^{14}}{10^{-6}}=10^{20}\frac{cm^{-3}}{sec}$