Question: What is the bandgap energy in semiconductor physics?

Options:

1. The energy required to free an electron from the valence band
2. The energy of the conduction band
3. The energy of the valence band
4. The energy lost during conduction

Correct Answer: The energy required to free an electron from the valence band

Solution:

The bandgap energy is the energy required to free an electron from the valence band to the conduction band in a semiconductor.