How does boron doping create holes in silicon?

In the context of semiconductor electronics, boron doping creates holes in silicon through a process of atomic substitution.

Silicon atoms have four electrons in their outer shell, which they share with neighboring atoms to form a stable covalent bond structure. Boron, however, is a trivalent atom with only three electrons available in its outer shell.123

When a boron atom is substituted for a silicon atom in the crystal lattice, it lacks the fourth electron necessary to complete the four covalent bonds with its neighboring silicon atoms. To compensate, the boron atom "accepts" an electron from the surrounding structure. This creates an electron deficiency, or a positively charged site, known as a hole, in the valence band. Because boron acts as an acceptor of electrons, this process results in a p-type (positive) semiconductor, where these holes serve as charge carriers that can migrate through the crystal lattice to conduct electricity.1234