Which of the following statements is correct regarding the doping levels of the emitter, base and collector regions in a bipolar junction transistor (BJT)?
1
The doping levels of the emitter, base and collector are all the same.
2
The emitter is lightly doped, the base is heavily doped and the collector is moderately doped.
3
The emitter is moderately doped, the base is heavily doped and the collector is lightly doped.
4
The emitter is heavily doped, the base is lightly doped and the collector is moderately doped.