Non-uniform dielectric polarization

  • Thread starter Stanley514
  • Start date
  • #1
411
2

Main Question or Discussion Point

I thought if it`s possible to create a device which would be a something average between
capacitor and solar cell.In solar cell we are getting non-uniform charge separation which is then used to produce current with help of low voltage electric field.Current which could be acheived in solar cell could be very powerfull.Yet there no problem of electric discharge because there is no charge separation on macro scale in solar cell and it is random.
What prevents to use the same principle in ferroelectric capacitor?Is it possible to create very strong random dipole polarization without polarization on macro scale and after that apply external low voltage field (when needed) to generate usable current?
 

Answers and Replies

  • #2
57
0
From what you've told of the solar cell, if there is no polarization on the macro scale for the ferroelectric capacitor, then there wouldn't be a discharge, just as in the solar cell. Also, in the solar cell, there's cheap energy source to cause an inhomogeneous charge distribution. Even though the voltage caused is weak, you're still exploiting an energy source that is technically free. I guess, that's why its not feasible. Last I read, the most efficient solar cell is 40.7%. In the case of a ferro/ferrielectric material, it'd be worse, because you would be expending energy sources not quiet as "cheap" as solar energy, to produce some weak current.

Anyhow, I was wondering what exactly is this phenomenon of "very strong localized randomness", and how prevalent is this. Is what you are saying similar to antiferromagnets where the adjacent dipole moments are antiparallel and yet, I guess, on a macro scale the material is no different from a "completely random" orientation of spins (?). Can someone guide me through some literature, or sources where I can read up on this?
 
Last edited:
  • #3
411
2
Solar cell would be able to work as energy storage (not only as energy converter) if electron-hole charge separation would be able to exist indefenitly long.In this case you would be able to regulate electric field to enforce produce it a useful current on demand.I guess it would be a very energy dense energy storage.But because electron-hole recombinations happen in milliseconds, it wan`t.
In ferroelectric charge separation could exist indefinitly long.I don`t know how to create some non-uniform charge separation in ferroelectric similar to that in photocell.Maybe some non-uniform electric fields could help?Then by applying external low voltage electric field those randomly oriented dipoles will alline and create some macroscopic electric potential.At least there is some mentions in Internet that there exist something similar to non-uniform electric charge.
http://www.sciencedirect.com/scienc...f6d20fd378ed3041274a5b8bf55afe1&searchtype=a"
Also there is statements that antiferroelectric capacitors could have energy density greater than ferroelectric.http://www.trstechnologies.com/Products/Specialty_Capacitors/high_energy_capacitors.php" [Broken]
I guess because of similar reasons.The idea I propose will extend idea of antiferroelectric capacitors.
 
Last edited by a moderator:

Related Threads on Non-uniform dielectric polarization

Replies
40
Views
7K
Replies
3
Views
2K
  • Last Post
Replies
2
Views
1K
Replies
2
Views
2K
Replies
3
Views
3K
Replies
3
Views
816
  • Last Post
Replies
0
Views
808
Replies
0
Views
2K
  • Last Post
Replies
1
Views
2K
Top