Question

What happen if collector is lightly doped in transistor?

Answer 1

we make Emitter to emit more electrons(for current flow)so,it is highly doped when compared to other two....purpose of collecter is to collect the electrons coming from Emitter via Base.Since Colectro duty is to only collect not emit it is moderately doped....Morever it should have less surface area when compared to that of Emitter to reduce power dissipation..

hope it pays...

Note: Base should always have less doping and less suraface area.The latter is to reduce the transit time (an important parameter which decides delay and frequancy of operation) and i am not clear abt the former...but if also having it's role