Valence control method of co-doping for the fabrication of metallic silicon from the first-principles calculations

We propose the co-doping method for the fabrication of p-type Si as low-resistive as metals. This method is the doping method in which two sorts of element are doped into host crystal simultaneously. The optimal configurations for B/Ge, B/P in Si were studied by the first-principles calculation. It was found that an energy gain is obtained as Ge or P atoms are placed nearby a B atom. This result indicates that the solubility limit of B increases. (C) 2001 Elsevier Science B.V. All rights reserved.