A simple theoretical approach to grain boundaries in silicon

The question of atomic and electronic structure of grain boundaries in Si is addressed within the tight-binding approximation with a self-consistent charge neutrality condition. The authors use simultaneous recursion in real space to calculate inter-atomic forces and relax reconstructions of Sigma =3(112) and Sigma =5(130) grain boundaries. Consequences of over- and under-coordination at defects are illustrated, and relaxed atomic structures are compared with recent lattice imaging and electron diffraction experiments.