P-type semiconductors are created by doping silicon with trivalent impurity atoms like boron. These impurity atoms add holes to the silicon crystal structure when they form covalent bonds. As a result, the majority charge carriers in p-type semiconductors are holes. P-type and n-type semiconductors can be combined to form a p-n junction, with a depletion region forming at the boundary between them. This p-n junction is the basis for diodes and other electronic devices.