Density functional theory study of the shallow boron impurity in 3C-SiC and comparison with experimental data

In this paper, we present a detailed study of the boron impurity in 3C-SiC (B sub(Si)) in the cluster (CL) and supercell (SC) approximations, using representative local, gradient-corrected, and hybrid density functionals. Comparison of the theoretical spin-Hamiltonian parameters, calculated in the CL approximation using nonlocal density functionals, with the corresponding experimental values for the so-called shallow boron in SiC has proved that the latter is the (ProQuest: Formulae and/or non-USASCII text omitted) defect. We analyze the motional effects in the electron paramagnetic resonance spectra, as well as the site dependence of the symmetry and SH parameters of (ProQuest: ... denotes formulae and/or non-USASCII text omitted). The dependencies of the calculated structural and energetic parameters on the size of the model space both for SC and CL methods are presented. The calculated relative formation energies and transition energy levels for the neutral B sub(Si) and BC centers reveal substantial finite-size effects. A simple extrapolation scheme indicates that the supercells with up to 10 super(5) atoms are required to achieve the desired accuracy level of 0.1 eV. Calculations suggest that B sub(C) impurity is a hyperdeep acceptor, which acts as the electron trap rather than increases the p-type conductivity.