Codoping in wide band-gap semiconductors

We review our recent proposal of a "codoping method (using both n- and p-type dopants at the same time)" for the fabrication of a low-resistivity wide band-gap semiconductors based upon ab initio electronic structure calculations. Following codopind methods are proposed; (1) GaN: Si-Ga+2Mg(Ga)(or Be-Ga), H+2Mg(Ga)(or Be-Ga), and O-N+2Mg(Ga)(or Be-Ga), (2) AlN: O-N+2C(N), (3) ZnSe: In-Zn+2N(Se), Cl-Se+2N(Se), Li-Zn+Cl-Se (or I-Se), and Te-Se+2N(Se), (4) CuInS2: V-Cu+In-Cu+2P, and (5) Diamond: B+2N, and H+2P, and (6) ZnO: Al+2N. We compare our prediction with the recent sucessful codoping experiments.