Distinguish between n-type and p-type semiconductors on the basis of energy-band diagram.

Explanation

The energy band diagram of n-type semiconductor has been shown in Fig. and of p-type semiconductor in Fig. From these energy band diagrams, we note that, in n-type semiconductor the forbidden energy gap is reduce by donore energy state and electrons are majority carriers. In p-type semiconductor, the forbidden energy gap is reduced by acceptor energy state and holes are majority carriers.
n-type semiconductor is obtained by doping a pure germanium or silicon semiconductor with a suitable impurity atoms of valence five like phosphosous, antimony and bismuth etc. p-type semiconductor is obtained by doping a pure germanium or silicon semiconductor with a suitable impurity atoms of valence three like aluminium, boron, indium, etc.