First of all, thanks for writing the article, help me greatly to understand lectures. But I do have a few questions. Let me quote something you said and then I'll discuss my concerns.
Let’s take a look at the process one step at a time. We’ll look at the n-type side first: When we attach the p-type region, the electrons, which are in extremely heavy concentration in the n region will want to diffuse, or spread out into the p region. And they do! But consider what happens when the first electron leaves the n region: we now have a charge imbalance. That free electron that diffused into the p region left behind its donor atom, a donor atom with fifteen protons, and, now, only fourteen electrons. That donor atom now has a positive charge. Every other electron that leaves the n region will likewise leave behind another positively charged acceptor ion.
ok, so were putting the n-type region right next to the p-type region? are there anything that separates? or just air? I'm guessing they're very very close to each other here. Also, since the n-type region has more electrons than holes, when the electron leaves the n region and into the p region, doesn't it leave behind a neutral atom? You said when it does that, we have a "charge imbalance", but wasn't a charge imbalance in the first place since the n-type region is extrinsic. To be it seems like the material will contain less electrons. Also, because so many electrons are packed together, like charges repel, so when the electrons will be happy to leave, and continued to be pushed away, there won't be any holes to pull it back. Maybe I misread something, but I've been going back and forth a lot and still unclear about this. It'll be helpful if you could clarify for me.
Thanks
|
RSS Updates