$(6\mathrm{.}37)$ Consider

$()$

$()()$

R

C n n C p p

C C N np n

R R

n p

n p t i

n p $$

$+++$

$$

$==$

$(\text{'}\text{'}$

$2$

$,$

and the definitions:

n t

n

p t

p C N C N

$1$

and

$1$

$00==.$ Let $$p$0=10-7$ s and $$n$0=5\backslash$times

$10-7$ s$.$ Also let n$=$ p$=$ ni $=1010$ cm$-3.$ Assume very low injection so that $$n

$<<$ ni$.$ Calculate R$/$n for a semiconductor which is $($a$)$ n$-$type $($n$0>>$ p$0)$; $($b$)$

intrinsic $($n$0=$ p$0=$ ni$)$; $($c$)$ p$-$type $($p$0>>$ n$0)$