First Principles XPS Calculation for the B Defects in SiC

We investigate the core-level X-ray photoelectron spectroscopy (XPS) spectra of various defects containing boron in silicon carbide (SiC) using a first principles calculation with careful evaluation of the local potential boundary condition. It is found that a 512-atom cubic supercell for 3C-SiC and a 576-atom hexagonal supercell for 4H-SiC are required for convergence of the XPS binding energy to within 0.1 eV. The XPS binding energies of SiC have considerable site dependence owing to the electronegativity difference between Si and C. The difference of XPS binding energies between the Si and C substitutional sites is 3.4 eV.