I have read so much about PN junctions, but I simply still don't get all of it. Every description I ever read when they are explaining Forward Biased says something about the depletion region, barrier voltage etc, and I believe I get most of that, but what I do not understand is how there is ever any net current in either direction when electrons and holes continue to constantly recombine with one another. Either the holes or the electrons must be able to continue on in some way for their to be any sort of useful current no?
In short, I need these couple of sentences from Wikipedia explained on PN Junctions with my comments of what I understand and do not understand included.
"With forward bias, the depletion region is narrow enough that electrons can cross the junction and inject into the P-type material( got it). However, they do not continue to flow through the P-type material indefinitely, because it is energetically favorable for them to recombine with holes( makes sense..but then what continues on to create current flow?). The average length an electron travels through the P-type material before recombining is called the diffusion length, and it is typically on the order of microns.[2]
Although the electrons penetrate only a short distance into the P-type material, the electric current continues uninterrupted( What?! How? I thought electric current WAS flow of electrons or holes?), because holes (the majority carriers) begin to flow in the opposite direction"
I'd appreciate any help that anyone with knowledge of the subject would care to offer. Thank you for your time.
In short, I need these couple of sentences from Wikipedia explained on PN Junctions with my comments of what I understand and do not understand included.
"With forward bias, the depletion region is narrow enough that electrons can cross the junction and inject into the P-type material( got it). However, they do not continue to flow through the P-type material indefinitely, because it is energetically favorable for them to recombine with holes( makes sense..but then what continues on to create current flow?). The average length an electron travels through the P-type material before recombining is called the diffusion length, and it is typically on the order of microns.[2]
Although the electrons penetrate only a short distance into the P-type material, the electric current continues uninterrupted( What?! How? I thought electric current WAS flow of electrons or holes?), because holes (the majority carriers) begin to flow in the opposite direction"
I'd appreciate any help that anyone with knowledge of the subject would care to offer. Thank you for your time.