So it took me a little bit to understand this, but I want to make sure I have a few things right.
First of all, when a Crystal Structure with One side N-Doped, One Side P-Doped are in the same crystal lattice, the Electrons from the N-side are going to jump over to the P-side at the Junction where they meet.
When they jump, this creates a Positive charge on the N-Side (Since electrons are leaving) and a Negative Charge on the P-Side (Since Electrons are being added) And these 2 sides were "Neutral" before.
My few questions is in regards to this. (Lets pretend no voltage is applied)
- The Depletion region makes sense, but the "equilibrium" with the depletion region: is that because the Negative charge over on the P-Side near the junction is opposing any more electrons from coming over? If so....how come more "holes" aren't moving into the negatively created region on the P-side...like I guess how come the negatively created region isn't jumping all over the place on the P-side, or for that matter, why aren't more extra electrons just jumping into the positive side created on the N-doped part near the junction.
Like Look at the + Side in the "Space charged region".....why aren't the electrons jumping from the N-doped neutral region? Seems like the Free electrons should want to be attracted to the + side of the space charged region. Or is it just because the electric field from the negative side near the P-doped region near the junction is pushing them away?
- Since the concept of "holes" just confuses me more, and I like to just think of it as electron movement (Which is what it is anyways right?).....what exactly happens when the depletion region expands due to reverse bias? I understand Forward Bias....the Electrons are being "FORCED" over the Opposing Electric field created by the Depletion region. But when it's reverse bias what is "really" happening? Obviously "holes" aren't getting pulled out since that makes no sense(or is it that actually electrons are getting "shoved" to the other side by the + terminal), Is the depletion region "basically" expanding one way sorta, like towards the P-doped side. Since the electrons are getting pulled out of the P-doped side it's just going to create bigger gap....but why aren't electrons from the other side just jumping right back into the gap? Or is it because the Negative charged region is getting filled up more and more towards the P-doped side, which opposes any more electrons from coming over?
Sorry for the long questions, just "Holes" moving really whacks it up for me since the way I imagine it is just electrons flowing, and that makes the most sense to me!