We systematically investigated the vibrational properties and total energy of defects containing two boron atoms in Si by a first-principles calculation. Our calculations were performed for six configurations with two substitutional B atoms, including up to the fifth-nearest neighbors, which are found to be electrically active, and for the ⟨001⟩ B2 cluster. The total energy calculation reveals that two substitutional boron atoms prefer configurations remote from each other because of tensile stress. Comparing calculated IR frequencies and isotope shifts with experimental ones, we found that the previous interpretation is inadequate for the vibrational modes of the first-nearest-neighbor B2 cluster. Furthermore, it is shown that the theoretical IR peaks of ⟨001⟩ B2 give a reasonable explanation for the experimental ones whose origin has not been clarified for more than 30 years. Thus the existence of ⟨001⟩ B2 is confirmed with respect to the atomic structure. We further calculated the electronic structure of ⟨001⟩ B2, and found it to be consistent with near-edge x-ray absorption fine-structure spectroscopy data.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2001 Jan 25|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics