Question

In semiconductors, the forbidden energy gap between valence band and conduction band is of the order of :

• A. $1eV$
• B. $5eV$
• C. $1keV$
• D. $1MeV$

Answer 1

Answer: (A)

In semiconductors at room temperature, some of the electrons acquire enough energy to jump to conduction level. Thus, to obtain large number of electrons in conduction band, some energy has to be supplied to the electrons present in the valance band. This energy must be equal to the difference between conduction band and valance band. For semiconductors, it is of the order of $1eV$.