HELP...What is the depletion zone in a n-p diode?? (1 Viewer)

[DavidB]

.....come on boyz and girlz...someone..?

 

[helper]

N-semiconductor has a free electron that does not fit in the lattice, as a group 5 element has been added and the 5th electron will not fit in the lattice.
P-semiconductor has a hole in the lattice where a Group 3 element is and cannot share an electron.

When an n is placed next to a p, some of the free electrons will move and fill in the holes in the p semiconductor. This forms a connection area with no p-type free electrons or n-type positive holes.

This area is the depletion zone.

 

[DavidB]

Legend...

so what that means is that once they are put together...a depletion zone forms ova time.
Then afta that, as a potential difference is supplied...holes and electrons move (as normal semiconductors).

Am i right am i right???


Oh yeh one more question. When hertz discovered the whole photoelectric effect, by shining UV light onto the gap when it was larger...exactly what happens?
DO the photons in the light give the electrons enough energy to jump the gap???
(ah i think im lost)

thanx

 

[helper]

The depletion zone will occur very quickly.
Your right from there but the current can only flow in one direction. If you put the potential on in the wrong direction the depletion zone just grows.

 

[DavidB]

ah i think he missed ma secont question...

anyone else know??

 

[helper]

Firstly he didn't shine UV onto it. He found by accident putting apiece of glass in front that blocked UV the spark was smaller. Without the glass it was longer because of the presence of UV.

The UV has enough energy to allow an electron to be removed as the energy is greater than the work function. Thus the electron has more KE and could travel further.