I am a layperson trying to understand how the bipolar junction transistor works from this excellent article: https://spectrum.ieee.org/transistor-history
The relevant paragraphs are as follows:
Consider an NPN device. The base is p-type, so it has excess holes. But it is very thin and lightly doped, so there are relatively few holes. A tiny fraction of the electrons flowing in combines with these holes and are removed from circulation, while the vast majority (more than 97 percent) of electrons keep flowing through the thin base and into the collector, setting up a strong current flow.
But those few electrons that do combine with holes must be drained from the base in order to maintain the p-type nature of the base and the strong flow of current through it. That removal of the “trapped” electrons is accomplished by a relatively small flow of current through the base. That trickle of current enables the much stronger flow of current into the collector, and then out of the collector and into the collector circuit. So, in effect, the small base current is controlling the larger collector circuit.
From these paragraphs, if I understand correctly, a more positive voltage at the base increases emitter-collector current flow. However, if one applied a sufficiently negative voltage at the base, all the holes in the base would be obliterated, thus turning the transistor into a giant slab of N type silicon and supporting a high emitter-collector current.
Could you help me reconcile the discrepancy in my understanding here?