Question

Energy gap between valence band and conduction band of a semiconductor is:
(A) zero
(B) infinite
(C) $1\,eV$
(D) $10\,eV$

Answer 1

Hint The semiconductors are the materials which have the property of conductivity between the conductors and the insulators, which means the semiconductor material partially conducting and partially nonconducting. The semiconductor materials are pure such as silicon and germanium or compounds such as gallium arsenide.

Complete step by step answer
Semiconductors are characterized by their extraordinary electric conductive property, somewhere close to that of a conduction and insulation. The difference between these materials can be identified from the quantum states for electrons, every one of which may contain zero or one electron (by the Pauli exclusion principle). These states are related with the electronic band structure of the material. Electrical conductivity emerges because of the presence of electrons in states that are delocalized (stretching out through the material), anyway to transport the electrons a state must be randomly filled, containing an electron just piece of the time. If the state is constantly busy with an electron, at that point it is inert. The energies of these quantum states are basic, since a state is halfway filled just if its energy is close to the Fermi level (see Fermi–Dirac measurements).

There are two types of semiconductor materials, they are n type semiconductor and p type semiconductor. In the n type semiconductor, there are a greater number of the electrons and a smaller number of the holes. In the p type semiconductor, there are a greater number of the holes and a smaller number of the electrons. The energy gap between the insulator is more than the $1\,eV$ and the energy gap between the conductor is less than the $1\,eV$ and the energy gap between the semiconductor is almost equal to the $1\,eV$.

Hence, the option (C) is the correct answer.

Note The energy gap of the semiconductor is almost equal to the $1\,eV$ and the energy gap value of the semiconductor is different for the different material. For example, the energy gap for the silicon semiconductor is $1.1\,eV$, and the energy gap value for the gallium arsenide is $1.41\,eV$.