Two patterns of the Si[001](130) symmetrically-tilted grain boundaries were established using two procedures: One was atomic relaxation at 0K, and the other was high-temperature treatment, plus 0K relaxation. The relaxation and subsequent electronic calculations were based on the density functional theory method, while the empirical Tersoff potential was employed to conduct the high-temperature equilibration. The results showed that the high-temperature pre-processing was indispensable to avoiding local minima, and the two resultant configurations agreed well with those in the literature. Electron localization functions were adopted in order to revise the conventional Si-Si bond-length criterion, refreshing the distortion details. The band-gap structures of the two systems were completely different, and the absence of gap states was confirmed in the more stable one. Potential barriers were found to be quite high at the grain boundaries in both structures, and defect-related localized states were reckoned to account for such facts besides gap states though may be to a lesser degree.

Atomic and Electronic Structures of Si[001](130) Symmetric Tilt Grain Boundaries Based on First-Principles Calculations. W.L.Huang, W.Ge, C.Li, C.Hou, X.Wang, X.He: Computational Materials Science, 2012, 58, 38-44