Silver thin films have been created by room temperature deposition on a Ga/Si(111)-√3 x √3 surface and their valence band structures and core levels have been measured by angle-resolved photoelectron spectroscopy (ARPES). Discrete quantum-well states (QWSs) quantized from the Ag sp valence band are observed already at 3 monolayers (ML). The characteristics of the QWSs have been examined in the phase accumulation model for thicknesses between 3 and 12 ML. The phase shift and QWSs binding energies dependence with Ag film thicknesses have all been consistently derived. In-plane energy dispersion follows a parabolic curve, and the effective mass of the QWSs shows an increasing trend with binding energies as well as with reduced film thicknesses. Furthermore, the ARPES measurements reveal umldapp mediated QWSs around the (M)over-bar points of the Si(111) 1 x 1 surface Brillouin zone. The study confirms that the Ga/Si(111)-√3 x √3 surface is a good substrate for growing uniform ultrathin Ag films in room temperature conditions.

Silver thin films have been formed by room temperature deposition of Ag on a Ga/Si(111) (√3 × √3)R30° surface. Scanning tunneling microscopy and spectroscopy (STM/STS) have been used to study both the clean Ga/Si(111) (√3 × √3)R30° surface and Ag films with different coverages. For the film formation, Ag first grows into 2D islands on Ga/Si(111) (√3 × √3)R30°. The first layer of the islands forms atomic lines with three-fold symmetry in the 1 × 1 direction of the underlying Si(111) substrate. From a 2 ML coverage, the growth becomes layer-by-layer mode. STS measurements have been performed on Ag films with different coverages inorder to investigate their electronic structures. Between 2–4 ML, the STS spectra reveal 2 and 3 peaks below the Fermi level. These peaks move towards the Fermi level with increased film thicknesses and thus share the same behavior as those of quantum well states (QWSs). The energy positions of the peaks have been compared with valence band photoelectron spectra in order to assign them to various parts of the QWSs. In addition, the photoemission results also confirm the existence of QWSs for a 2 ML Ag film on Ga/Si(111) (√3 × √3)R30°.

Silver thin films have been formed by room temperature deposition of Ag on In/Si(111)-√3 × √3. The Ag films have been investigated using both angle-resolved photoelectron spectroscopy (ARPES) and scanning tunnelingmicroscopy and spectroscopy (STM/STS). This creates a powerful link between the electronic structures and the film morphology. The valence band spectra show a clear evidence of quantum well state (QWS) formation already for a 2 monolayer (ML) film. This QWS moves towards the Fermi level for the 3 ML film, which also reveals a second QWS. The QWSs’ dispersions have been plotted along the ΓM and ΓK symmetry lines of the 1×1 surface Brillouin zone (SBZ), where the ΓM direction shows the umklapp-mediated QWSs. The valence band spectra for the 3 ML Ag film also show a strong Ag sp band close to the edge of the Ag(111) 1×1 SBZ. In the STS spectrum from 2 ML, two peaks are visible below the Shockley surface state. These peaks are compared with the ARPES data and attributed to different features of the QWS

Silver thin films have been formed on the Sn/Si(111)-(√3 ×√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)-(√3 ×√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.