By my understanding, as long as the P layers are properly doped (to have fewer free electrons), the electrons could not flow between collector and emitter until the P is given a satisfactory level of charge, as otherwise the base layer could not pull electrons from the poles. In this case, why can't the N layers be just made of simple conductors, like copper? What is special about the negative doping process that makes it different to just a conductor? Is it to do with polarising the flow of electricity?
E.g. on this diagram, why couldn't we just replace the red bits with copper, provided we keep the blue bit positively doped? More specifically, what is the difference between these regions and your standard conductors?
For reference, I really don't know a lot about this area: all of my knowledge comes from reading (this article)[https://www.explainthatstuff.com/howtransistorswork.html] followed by a skim though the (Wikipedia)[https://en.m.wikipedia.org/wiki/Transistor?wprov=sfla1]