Layer-by-layer control of Ag film growth on Sn/Si(111)-(√3 x √3)-R30°

SURFACE SCIENCE

卷:701

Article

Starfelt, S.¹  Laven, R.¹  Johansson, L. S. O.¹  Zhang, H. M.¹ 

[1] Karlstad Univ, Dept Engn & Phys, SE-65188 Karlstad, Sweden

关键词: Quantum well states;    Thin films;    Semiconductor;    STM;    STS;    ARPES;   

DOI  :  10.1016/j.susc.2020.121697

来源: Elsevier

【 摘 要 】

Silver thin films have been formed on the Sn/Si(111)-(root 3 x root 3)-R30 degrees surface at room temperature. The film morphologies, growth and electronic structures have been studied by scanning tunneling microscopy/spectroscopy (STM/STS), low-energy electron diffraction (LEED) and angle-resolved photoelectron spectroscopy (ARPES). The first layer of Ag forms an interface which consists of atomic rows with three-fold symmetry oriented along the Si(111)-1 x 1 directions. On top of the interface, Ag grows as an uniform thin film, following a layer-by-layer mode. The electronic structures of the films have been studied by STS for coverages between 1-5 monolayers (MLs). The STS spectra show peaks in the occupied electronic states which move towards the Fermi level with increased film thicknesses. These peaks have been attributed to quantum well states. ARPES measurements have been performed for 1 and 2 ML Ag coverage on Sn/Si(111)-(root 3 x root 3)-R30 degrees, where the resulting thicknesses were confirmed by STM. The spectra reveal that quantum well states appear first for the 2 ML film.

【 授权许可】

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