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How does boron doping change the electrical conductivity of silicon and germanium?

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A color-coded periodic table of the elements displays each element's symbol and atomic number, with categories such as alkali metals, noble gases, halogens, transition metals, and actinoid elements distinguished by different background colors. — boron group element Modern version of the periodic table of the elements (printable).

Boron doping increases the electrical conductivity of silicon and germanium by transforming them into p-type semiconductors.123

Because boron is a trivalent element with only three electrons available for bonding, its substitution for a silicon or germanium atom in the crystal lattice creates an electron deficiency. This deficiency is referred to as a "hole," which acts as a positively charged site in the valence band.124

When an electric field is applied, these holes can migrate through the crystal lattice, facilitating electrical conduction. By intentionally introducing these acceptor atoms, the material's ability to conduct electricity is significantly enhanced compared to its intrinsic, pure state.124