Physics - Semiconductors Question with Solution | TestHub

At absolute zero temperature ($0\text{ K}$), the valence band of a semiconductor is completely filled and the conduction band is completely empty.

At room temperature, some electrons in the valence band acquire sufficient thermal energy to jump across the energy gap into the conduction band. This leaves behind vacant energy states (holes) in the valence band.

Therefore, at room temperature, the valence band becomes partially empty and the conduction band becomes partially filled.

Answer: the valence band is partially empty and the conduction band partially filled.