P-type dopant within semiconductors
Boron is electron-deficient, possessing a vacant p-orbital, with only three outer electrons. Pure silicon structures, with four outer electrons share electrons in a lattice-structure. Boron is therefore used as a P-type dopant within semiconductors, as when mixed into the silicon lattice it forms "holes" in the lattice where a silicon electron has nothing to bond to. The absence of an electron creates the effect of a positive charge, hence the name P-type. Semiconductors have junctions of type N-P-N between positively and negatively charged parts. Holes can conduct current. A hole happily accepts an electron from a neighbour, moving the hole over a space. This P-type silicon is a good conductor of electricity.