BJT Working

Working of Transistor

Generally, silicon is used for the construction of the transistor because of various characteristics like their high voltage rating, greater current, and less temperature sensitivity. As shown in the figure, the emitter-base section in forward biased carries the base current which flows through the base region. The magnitude of the base current is very small. This base current causes the electrons to move into the collector region and the same time create a hole in the base region.

As we know that the base of the transistor is very thin and lightly doped as a result has less number of electrons as compared to the emitter. The few electrons of the emitter are combined with the hole of the base region and the remaining electrons are moved towards the collector region and leads to flow of collector current. Thus we can summarize that the large collector current is obtained by varying the width of the base region