|Oct22-07, 10:31 AM||#1|
PN Junction Question - Current
I guess my most general question would be:
Given a P/N junction. Lets say two circular discs, one P one N. There obviously exists some Vgap, and applying some voltage across it excites the electrons, then it emits light (very basic LED or something).
Now, what if you took a piece of wire, and coiled it, and put it around the diode. Lets say for arguments sake you theoretically only put the coil around the N part.
Now you run a current through the coil. This creates a B field in the +-Z direction for the N part, which, since semiconducting, creates a current in the Lz direction (loop about the Z axis). Now this current doesn't really go anywhere, right? It just spins around and around.
What I'm wondering is : Would this induced loop current have ANY effect on the Vgap energy (the barrier). I'm figuring perhaps theres something due to scattering, or something else.
I have a feeling it would really only change the free electrons, which might change the intensity, but not the energy of the gap.
Can someone tell me?
|Oct24-07, 10:24 PM||#2|
I don't believe it will make any difference since the magnetic field lines are parallel with the normals to the planes of the n-p junction if I'm reading the description correctly. And I take it the current is steady/constant?
|Oct25-07, 10:09 PM||#3|
Indeed. Thats what I was wondering. There would be both the current across the junction, as well as a circular current(which was induced by the field). This is purely a hypothetical. I didn't think it would have any effect, but I couldn't reason out why. I guess the fact that the charge carriers are mobile before a potential is applied across the junction doesn't make them and more or less energetic.
Same idea would work if you had a very very long p/n junction and ran a cross current tangential to the junction normal. Don't know if there would be any difference. Their current bands should be the same, dispersion relations the same; I'm not sure why I thought it would do anything. I guess there just seemed to be something where, if the P part has a cross current, wouldn't SOMETHING change?
|Similar Threads for: PN Junction Question - Current|
|WHY is drift current through a PN junction independent of applied bias voltages?||Atomic, Solid State, Comp. Physics||2|
|pn junction||Introductory Physics Homework||2|
|Junction Rule||Introductory Physics Homework||1|
|p-n junction||Classical Physics||6|
|Quick induced current from magnetic field question.. direction of current?||Introductory Physics Homework||1|