Synthesis of controlled semiconductors

The chemical approach to the synthesis of semiconductors is based on the electroneutrality of crystal lattices. Even minor concentrations of impurities, which do not have to conform with the more rigid requirements for the formation of mixed crystals have to be balanced electrically in order to enter a crystal lattice. A lattice can force the impurity to assume the valency of its own cations. For example, tetravalent vanadium is stabilized when vanadium is introduced into ZrO₂. The lattice may also cause the valency of some of its own cations to change in order to balance the effect of the impurity.