So I finally Dived into understanding the P-N Junction and Field Effect Transistors. (this may almost be teetering on the "Physics portion" of electronics, but it's still mainly for understanding the Field Effect....
This video (Which I hope was correct) really made it feel so simple or easier to understand. http://www.youtube.com/watch?v=CLLcRRBph90 (Just for reference, don't really have to watch it)
Anyways from What I understood, 2 Semiconducting Material (P being Positively charged and containing "holes" and N being Negatively charged (Extra Electrons) from whatever they were "doped" with. When a Positive current is applied it makes the Electrons "Jump" into the Holes, this causes current to flow (The free electrons in the N junction, jump into the P Junction).
Anyways I have a few questions.
- What exactly "causes" the electrons to jump into the Holes? and What exactly is happening when the electrons attach to the holes? are they immediatly unseated...or do new ones take their place or what? I understand the "holes" concept but im not sure I understand what happens when current is flowing. Do these electrons from the N Region go into the hole of a P region and then continue to flow, do they stay there? do they discharge someone else?
The Depletion Region
- So if you reverse bias a PN junction it causes electrons to go from the P region to the N region, causing a Depletion Region. First of all, does the P region have ANY electrons in it at all.... or is it doped to have absolutely zero (and therefore any free electrons are coming from your ground/- source (Battery/etc...) and therefore just filled with Holes?
And what exactly is "In" the depletion region? Just nothing...floating electrons? I understand the concept of a Depletion region, but im not sure I understand "Why" one forms when reverse Biasing a PN junction. The more voltage you apply the bigger the depletion region becomes, but is this because more electrons are getting shoved into the N region where they have no "holes" so they just "float around"? and cause a Neutral zone of sorts (or an insulator)? How comes they don't just bypass the N region....since it's technically still a conductive material? (Or do "some" actually still do..like a Reverse Biased diode will leak a little bit won't it?)
Also sidequestion: The PN Junction is obviously pretty important..but besides the fact were able to control the flow of electrons using the Depletion Region, and reverse biasing and such...is there any other "special" qualities that aren't talked about? Since Even Transistors almost seem like a Diode, and that seems to be the basis of the PN junction.
Sorry if this is borderlining Physics im just trying to nail down the PN junction into terms I can understand. (Although if anyone knows of any Physics books that go into detail on the PN Junction and Semiconductors/Electronics Physics I would appreciate it)