Deposition of Ga and As Adatoms on the Ge (111) and Si (111) Surfaces: A First-Principles Study
The (1×1) and (\(\sqrt 3 \times \sqrt 3 \))R30° (T4) structures of Ga and As adatoms on the Ge(111) and Si(111) surfaces are studied using the first-principles calculations. The surface energetics predicts, in some cases, a transformation of the T4 structure (surface covered with 1/3 monolayer (ML) of adatoms) into domains of the 1-ML covered (1×1) structure and areas of clean reconstructed surface. For As adatoms, such phase separation is favored on both substrates, while for Ga adatoms, it is only preferred on the Ge(111) surfaces. These results are compared with experimental observations.
KeywordsPhase Separation Adsorption Energy Uniform Coverage Segregation Energy Translational Unit
Unable to display preview. Download preview PDF.
- J.E. Northrup, Bull. Am. Phys. Soc. Vol.32 (1987) 720Google Scholar
- 5.M.A. Olmstead, R.D. Bringans, R.I.G. Uhrberg and R.Z. Bachrach, Phys. Rev. Vol.B34 (1986) 6401Google Scholar
- 10.As the Si(111)(7×7) surface energies quoted in Refs.  and  (+1.153 and +1.179 eV/((1×1) cell), respectively) are given with respect to the bulk, whereas all the surface energies in the present work are counted with respect to the ideal surface, we have calculated the surface energy of the ideal (1×1) surface with respect to the bulk, with the result +1.594 (+1.377) eV per (1×1) cell of Si (Ge) at 8 Ry cutoff. This situates the Si(111)(7×7) surface energy at -0.44 or -0.42 eV/((1×1) cell), under the energy of the ideal surface.Google Scholar