Write any two distinguishing features between conductors, semiconductors and insulators on the basis of energy band diagrams.

When comparing conductors, semiconductors, and insulators through energy band diagrams, two key features stand out:

Energy Band Structure

In conductors, the valence band and conduction band overlap, allowing electrons to move freely. This results in high electrical conductivity. In contrast, insulators have a large energy gap between the valence band and conduction band, preventing electron flow and leading to very low conductivity.

Behavior Under External Energy

Semiconductors have a smaller energy gap compared to insulators, which allows them to conduct electricity under certain conditions, such as when energy is supplied (e.g., heat or light). This unique property enables semiconductors to be used in electronic devices, where they can switch between conducting and insulating states.

• Conductors: Overlapping bands, high conductivity.
• Insulators: Large band gap, low conductivity.
• Semiconductors: Small band gap, variable conductivity.