Draw the "energy bands" diagram for a (i) pure semiconductor (ii) insulator. How does the energy band, foe a pure semiconductor, get affected when this semiconductor is doped with an acceptor impurity donor impurity? Hence discuss why the 'holes' and the 'electrons' respectively, become the 'majority charge carriers' in these two cases.

How does the energy gap of an intrinsic semiconductor vary, when doped with a trivalent impurity?

How does the energy gap of an instrinsic semiconductor vary, when doped with a pentavalent impurity?

How does the energy gap in an instrinsic semiconductor vary, when doped with a pentavalent impurity and a trivalent impurity. Draw their energy band diagrams.

Draw the energy band diagram when intrinsic semiconductor (Ge) is doped with impurity atoms of Antimony (Sb). Name the extrinsic semiconductor so obtained and majority charge carriers in it.

Expalin the formation of energy band in solids. Draw energy band diagram for (i) and conductor (ii) and intrinsic semiconductor.

How is p-type semiconductor formed? Name the major charge carriers in it. Draw the energy band diagram of a p-type semiconductor.

How is an n-type semiconductor formed? Name the major change carriers in it. Draw the energy band diagram of n-type semiconductor.

A pure semiconductor germanium or silicon, free of every impurity is called intrinsic semiconductor. A room temperature, a pure semiconductor has a very small number of current carriers (electrons and holes). Hence, its conductivity is low. When the impurity atoms of valence five or three are doped in a pure semiconductor, we get repectively n-type ot p-type extrinsic semiconductor. In case of a doped semiconductor. n_(e)n_(h)=n_(i)^(2) , where n_(e) and n_(h) are the number density of electrons and holes respectively and n_(i) is the number density of intrinsic charge carriers in a pure semiconductor. The conductivity of extrinsic semiconductor is much higher than that of intrinsic semiconductor. (i) Name two materials to be doped in pure semiconductor of silicon to get p-type semiconductor n-type semiconductor. (ii) What do you learn from the above study?

Draw the enrgy ban diagrams of (i) n type and (ii) p type semiconductor at temperature Tgt0K in the case n type Si semiconductor the donor energy level is slightly below the bottom of conduction energy level is slightly above the tip of the valence band explai what role do these energy levels play in conduction and valence bands