Question

At zero Kelvin temperature, Silicon is a/an _____.
1. Conductor
2. Semiconductor
3. Superconductor
4. Insulator
5. None of the above

Answer 1

Correct Answer - Option 4 : Insulator

The correct answer is option 4 i.e. Insulator.

• Silicon is a metalloid and a semiconductor.
• Silicon behaves as an insulator at zero Kelvin because the electrons do not possess sufficient thermal energy to overcome the forbidden energy gap.
• The forbidden energy gap is defined as the difference in energy of the conduction band and valence band.
• The upper energy level is called a conduction band.
• The lower energy level is called a valence band.

Conductor	The forbidden energy gap is very less. The valence band partially overlaps with the conduction band at room temperature.
Semiconductor	The forbidden energy gap is less than 3eV. The valence band does not overlap with the conduction band at room temperature.
Superconductor	The forbidden energy gap is inconsequential. The valence band almost completely overlap with the conduction band at room temperature.
Insulator	The forbidden energy gap is more than 3eV. The valence band can never overlap with the conduction band at room temperature.