Electronics Forum / Basics / February 2006

Hi All,

I have a question on the currents in the PN Junction diode. This has
been bugging me for a lot of time.

When the PN junction is forward biased, how does the holes from the
P-type move into the N-type ?

Since for the fomation of hole in the N-type, a valency electron should
occupy the hole near the junction of P-type. But there are free
electrons in P-type, which can occupy the holes near junction of
P-type, considering the fact that their mobility is higher when
compared with holes.
Will the valence electrons in N-type has any chance to occupy the holes
of P-type, overcoming the speed of free electrons ?

Also when a hole is formed near the junction of N-type, dont you think
there is a chance  of free electron of n-type taking the placeof that
hole.

Please answer my question as soon as possible.

Thanks,
Beenu