Write clearly, why in the case of transistor (i) the base is thin and lightly doped and (ii) the emitter - Physics - Semiconductor Electronics Materials Devices And Simple Circuits

Question

Write clearly, why in the case of transistor (i) the base is thin
and lightly doped and (ii) the emitter is heavily doped

Decoder_2 · Accepted Answer

Dear
student,

Base in a transistor is lightly doped and made thin so that the
rate of diffusion of ions in it becomes negligible and emitter
current becomes approximately equal to the collector
current
Emitters
are thicker than the base as 
higher doping level 
means more of the carriers will be generated compared to a region
with less doping
Regards

Write clearly, why in the case of transistor (i) the base is thin and lightly doped and (ii) the emitter is heavily doped.