Creation of a metallic channel at theSn∕InAs(111)Bsurface studied using synchrotron-radiation photoelectron spectroscopy

Pb induced charge accumulation on InAs(111)B

“…Unfortunately, values at other coverages were not properly measured and cannot be used. However, the measured value is in good agreement with previous values from the InAs(1 1 1)-Sn surface [31]. The reversed polarisation brings back electrons closer to the surface.…”

“…At 4°off normal emission angle the intensity is practically zero. This is in agreement with previous observations of a metal induced free electron channel in the surface region [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]31,32,34,35]. An alternative interpretation could be quantum-well states within the metallic film, which has been observed for example in the Ag/Fe(1 0 0) system [36], and Pb/ Cu(1 1 1) [25].…”

“…The intensity peaks at 27 eV, while it decreases at higher photon energies to become practically null at 35 and 38 eV. The photon energy dependence is very similar to a recent report from the InAs(1 1 1)B-Sn surface [31]. It is however different from what has been reported on other surfaces with a stronger intensity at lower photon energies, for example 16.5 eV on the InAs(1 1 1)A surface in Ref.…”

“…Such shifts reflect changes in the surface band bending, and lead does accordingly not change the surface band bending from the clean surface. This is different from Sn on InAs(1 1 1)B that induces a 200 meV down ward band bending [31] and also from Co that induces an up ward band bending on the same surface [23]. It is however, similar to previous observations from Pb on InAs(1 0 0), where no additional Fermi level shift was observed [32].…”

“…Finally the changed photon energy dependence, compared to for example InAs(1 1 1)A, has been ascribed to a modified inner potential in the surface region due to the increased electron density [31].…”