Si (112) 高密勒指数面的理论研究

Large cluster models of Si₃₉H₃₂, Si₃₅H₃₀, Si₉₁H₆₄ and Si₅₈H₄₆ were used to simulate the Si (112) surface, respectively. The net charge and its distribution of these systems were calculated by means of semiempirical CNDO-SCF method. The results indicate that the cluster models Si₃₉H₃₂ and Si₃₅H₃₀ are not large enough to simulate the Si (112) surface, and the cluster of Si₉₁H₆₄ is a reasonable one for modeling Si (112) surface. The authors also found that the net charges existing at surface atoms are concentrated in the direction (or in the opposite direction) of the corresponding dangling bonds. This property is determined by the atomic structure of the surface.