- #1
kidia
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Can anybody explain to me why holes are found at the top of the valence band, whereas electrons are found at the bottom of the conduction band.
The valence band is the highest energy level in a solid material where electrons are normally located at absolute zero temperature. It is responsible for the electrical and chemical properties of the material.
The conduction band is the energy level just above the valence band where electrons are free to move and conduct electricity when an external electric field is applied to the material.
The valence and conduction bands are separated by an energy gap, also known as the bandgap. Electrons in the valence band cannot move to the conduction band without the input of external energy, such as heat or light.
The energy gap between the valence and conduction band is determined by the type of material and its atomic structure. Materials with larger energy gaps are insulators, while materials with smaller energy gaps are semiconductors or conductors.
The valence and conduction band play a crucial role in determining the electrical conductivity of a material. Materials with a smaller energy gap, such as semiconductors, have a higher electrical conductivity compared to insulators with a larger energy gap. This is because in semiconductors, electrons can easily move from the valence band to the conduction band, allowing for the flow of electric current.