Semiconductors

Energy Bands
The highest energy level for an electron at 0 K is called Fermi level. The Fermi level for intrinsic semiconductor lies in centre of valence and conduction band. For n type, it lies close to the valence band. For p type it lies close to conduction band.

Forward Biased
The dominant mechanism of Forward biased diode is diffusion.

Forward resistance is very low or zero.

Reverse Biased
The dominant mechanism of Forward biased diode is drift.

Reverse Resistance is infinitely high.

Common Base Connections
Here, the base is connected to both input as well as output.