Quantum-well states in ultrathin Ag(111) films deposited onto H-passivated Si(111)-(1×1) surfaces

Abstract

Ag(111) films were deposited at room temperature onto H-passivated Si(111)-(1x1) substrates, and subsequently annealed at 300 o C. An abrupt non-reactive Ag/Si interface is formed, and very uniform non-strained Ag(111) films of 6-12 monolayers have been grown. Angle resolved photoemission spectroscopy has been used to study the valence band electronic properties of these films. Welldefined Ag sp quantum-well states (QWS) have been observed at discrete energies between 0.5-2eV below the Fermi level, and their dispersions have been measured along the ΓK, ΓM (M ′ ) and ΓL symmetry directions. QWS show a parabolic bidimensional dispersion, with in-plane effective mass of 0.38-0.50mo, along the ΓK and ΓM (M ′ ) directions, whereas no dispersion has been found along the ΓL direction, indicating the low-dimensional electronic character of these states. The binding energy dependence of the QWS as a function of Ag film thickness has been analyzed in the framework of the phase accumulation model. According to this model, a reflectivity of 70% has been estimated for the Ag-sp states at the Ag/H/Si(111)-(1x1) interface.

Quantum electronic stability and spectroscopy of ultrathin Pb films onSi(111)7×7

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ProbingMocore valence onSr2FeMoO6half-metallic ferromagnets and the

“…In the range of explored energies h the energy resolution is about 50 meV. 17,18 Samples have been scratched in situ in ultrahigh vacuum ͑Ͻ3 ϫ 10 −11 torr͒ by using a diamond saw. Surface contamination has been monitored by the eventual presence of 1s-C core level (see inset in Fig.…”

Time-evolution growth of Ag nanolayers on differently-passivated Si(001) surfaces

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