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Question
Answer the following question.
What is the importance of the energy gap in a semiconductor?
Solution
- The gap between the bottom of the conduction band and the top of the valence band is called the energy gap or the bandgap.
- This bandgap is present only in semiconductors and insulators.
- The magnitude of the bandgap plays a very important role in the electronic properties of a solid.
- Bandgap in semiconductors is of the order of 1 eV.
- If electrons in the valence band of a semiconductor are provided with energy more than bandgap energy (in the form of thermal energy or electrical energy), then the electrons get excited and occupy energy levels in the conduction band. These electrons can easily take part in conduction.
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