Origin of the different reconstructions of diamond, Si, and Ge(111) surfaces - art. no. 016103

Ab initio calculations of the 2 x 1, c(2 x 8), and 7 x 7 reconstructions of the diamond, Si, and Ge(111) surfaces are reported. The pi -bonded chain, adatom, and dimer-adatom-stacking fault models are studied to understand th e driving forces for a certain reconstruction. The resulting energetics, ge ometries, and band structures are compared for the elemental semiconductors with different atomic sizes, and chemical trends are derived. We show why the lowest-energy reconstructions are different for the group-IV materials considered.