In the context of semiconductors, a 'hole' refers to an absence of an electron in the crystal lattice. This vacancy acts like a positive charge carrier, allowing for the movement of charge within the semiconductor material. When an electron moves from one energy level to another, it leaves behind a hole in its original position. This hole can then be filled by another electron from a neighboring atom, thereby facilitating electrical conduction in materials like silicon.
This concept is fundamental in understanding how semiconductors function, particularly in the formation of p-type semiconductors. The presence of holes is crucial for the operation of various electronic devices, as they enable the movement of positive charge, complementing the flow of electrons (negative charge carriers) in the material. Thus, in semiconductor physics, holes are a key component of charge transport and play an essential role in the behavior of semiconductor materials.