Seminarium "Teoria i Modelowanie Nanostruktur"
sala 1.02, ul. Pasteura 5
Dr Kamil Czelej (Warsaw University of Technology)
Ab initio calculations of point defects and their complexes in diamond
To understand the impact of certain point defects on the electronic structure, electrical, magnetic, and optical properties of diamond, I performed theoretical calculations based on advanced hybrid density functional theory.One of the most relevant problems in the field of diamond–based high–power electronics is relatively high donor activation energy of phosphorus–doped diamond. The calculations performed in this thesis indicate that arsenic and antimony can theoretically generate shallower donor level than substitutional P, however, due to very high formation energy, the fabrication of As– or Sb–doped diamond with reasonable concentration of these elements at substitutional site might be very challenging.The investigation of yet unidentified H-vacancy and H-P-vacancy complexes in diamond has been carried out employing the extended Hubbard model Hamiltonian with fully ab initio derived parameters was introduced to properly describe their electronic structure. Some of the investigated defects were found to be promising for quantum information processing application. Further the Ti-N and Ti-vacancy-N complexes has been studied.