Model of V Hg Incorporation in Arsenic-Doped HgCdTe: First-Principles Calculations

Following the suggestion that the As Hg – V Hg and As Hg –2 V Hg defect complexes are potential sources of carrier compensation observed in As-doped HgCdTe, we have studied the electronic properties and formation energies of these complexes. We find that these complexes are electrically active acceptors but have exceedingly high formation energies, meaning that they play no role in carrier compensation except at low temperatures. V Hg will thus likely remain as an isolated defect. Such a model of V Hg incorporation allows us to further predict the postgrowth As activation. Our prediction emphasizes the As Hg –2 V Hg complex as the starting defect for As activation, rather than the As Hg – V Hg pair as previously suggested.