First-principles calculations of twin boundaries in 3C-SiC, Si and diamond were performed on the basis of density-functional theory in the local density approximation. The formation energies and electronic properties of isolated and interacting twin boundaries were investigated. It was found that, in 3C-SiC, interacting twin boundaries which were separated by more than two Si-C bilayers were energetically more favorable. This implied the relatively frequent appearance of these defects. The effect of the spontaneous polarization that was associated with the hexagonal symmetry around twin boundaries was also studied and it was observed that the wave functions which belonged to the conduction- and valence-band edge states in 3C-SiC tended to be localized almost entirely on different sides of the faulted layers. There was no such feature in Si or diamond.

Energies and Electronic Properties of Isolated and Interacting Twin Boundaries in 3C-SiC, Si and Diamond. H.P.Iwata, U.Lindefelt, S.Öberg, P.R.Briddon: Physical Review B, 2003, 68[11], 113202 (4pp)