Density-functional calculations of carbon doping in III-V compound semiconductors

This article reports the results of investigations based on local-density-functional theory into the relative formation energies for single substitutional carbon atoms in nine III-V compound semiconductors. The calculations are performed using a supercell formalism derived from the AIMPRO real-space cluster method. Only a very slight trend is discernible down the periodic table. When a metal atom is replaced with carbon, it is energetically least favorable in the phosphides, very marginally lower energy in the arsenides, and ≈0.5--0.7 eV lower in the antimonides. The situation is approximately reversed when a P, As, or Sb atom is substituted by a C atom: for the In compounds the energy is ≈0.4--0.8 eV higher than for the Al and Ga compounds.