An amphoteric dopant can act as a donor impurity or an acceptor impurity according to its incorporated lattice site or defect configuration. Silicon in gallium arsenide is the standard example: substitution on the gallium sublattice gives a shallow donor, while substitution on the arsenic sublattice gives a shallow acceptor. Its electrical effect therefore depends on growth conditions as well as total silicon concentration.[ref]
Thermal equilibrium concentrations of the amphoteric dopant Si and the associated carrier concentrations in GaAs by Chang-Ho Chen and others. Abstract: neutral and ionized donor species occupy Ga sites; neutral and ionized acceptor species occupy As sites
New to topics? Read the docs here!