The electronic structure of a doped semiconductor is shown here. (c) Which region of the diagram represents the band gap?

Verified step by step guidance

1. Identify the two main regions in the diagram: Band A and Band B.
2. Understand that Band A represents the valence band (filled molecular orbitals) and Band B represents the conduction band (empty molecular orbitals).
3. Recognize that the band gap is the energy difference between the top of the valence band (Band A) and the bottom of the conduction band (Band B).
4. Locate the region between Band A and Band B in the diagram.
5. Conclude that this region represents the band gap.

Key Concepts

Band Gap

The band gap is the energy difference between the top of the valence band (filled molecular orbitals) and the bottom of the conduction band (empty molecular orbitals) in a semiconductor. It determines the electrical conductivity of the material; a larger band gap typically means lower conductivity, while a smaller band gap allows for easier electron excitation, enhancing conductivity.

Doping in Semiconductors

Doping involves adding impurities to a semiconductor to change its electrical properties. N-type doping introduces extra electrons, while P-type doping creates 'holes' or positive charge carriers. This process modifies the band structure, affecting the position and size of the band gap, which is crucial for tailoring the semiconductor's performance in electronic devices.

Energy Bands

Energy bands in solids arise from the overlap of atomic orbitals, leading to the formation of filled and empty molecular orbitals. The filled band corresponds to the valence band, while the empty band is the conduction band. The arrangement and separation of these bands, including the band gap, dictate the material's electrical and optical properties, influencing its behavior in applications like transistors and diodes.