Understanding the Depletion Layer in p-n Junction Formation

AI Thread Summary
In p-n junction formation, electrons from the n-type material combine with holes in the p-type, creating negative ions in the p-type and leaving positive ions in the n-type. The discussion highlights that these ions are not attracted to each other due to the presence of both an electric field and a diffusion force that balance in the space charge region. The ions do not migrate through the semiconductor's crystal lattice, which is made of silicon or germanium with impurities. This balance prevents the uniform distribution of ions across the junction. Understanding these forces is crucial for grasping the behavior of charge carriers in semiconductors.
dpacmittal
Messages
2
Reaction score
0
In p-n junction formation,
Electron from n-type combine with holes on p-type to form negative ions leaving behind positive ions on n-type.

Now, why aren't these negative ions and positive ions attracted by electron on n-type and holes on p-type respectively?

They restrict further movement of electrons or holes but why these ions themselves aren't moved with repulsive forces?

Both the above factors would've uniformly distributes the negative ions on positive side and positive ions on negative side. But this doesn't happens... why?
 
Engineering news on Phys.org
I don't fully understand your question but I think you're confused because you don't realize there is both an electric field and a diffusion force on the charge carriers, and in the space charge region, with no external electric field, they balance.

This page is very good and has more details (and lot's of great images).
See Figure A in particular.
http://en.wikipedia.org/wiki/P-n_junction
 
Last edited by a moderator:
es1 said:
I don't fully understand your question but I think you're confused because you don't realize there is both an electric field and a diffusion force on the charge carriers, and in the space charge region, with no external electric field, they balance.

This page is very good and has more details (and lot's of great images).
See Figure A in particular.
http://en.wikipedia.org/wiki/P-n_junction
Thanks :)



dlgoff said:
Remember that the semiconductor is a crystal lattice of silicon or germanium with an impurity that is http://hyperphysics.phy-astr.gsu.edu/hbase/solids/dope.html#c1", so these doping ions don't actually migrate through the crystal.

Take a look at this explanation of http://hyperphysics.phy-astr.gsu.edu/hbase/solids/pnjun.html#c2".

Welcome to PF

Yes, this was what I was looking for. Thanks :)
 
Last edited by a moderator:
Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
I have recently moved into a new (rather ancient) house and had a few trips of my Residual Current breaker. I dug out my old Socket tester which tell me the three pins are correct. But then the Red warning light tells me my socket(s) fail the loop test. I never had this before but my last house had an overhead supply with no Earth from the company. The tester said "get this checked" and the man said the (high but not ridiculous) earth resistance was acceptable. I stuck a new copper earth...
Thread 'Beauty of old electrical and measuring things, etc.'
Even as a kid, I saw beauty in old devices. That made me want to understand how they worked. I had lots of old things that I keep and now reviving. Old things need to work to see the beauty. Here's what I've done so far. Two views of the gadgets shelves and my small work space: Here's a close up look at the meters, gauges and other measuring things: This is what I think of as surface-mount electrical components and wiring. The components are very old and shows how...
Back
Top