Experimental correlation between photoemission matrix elements and LEED intensities in superperiodic structures

• Published in: Journal of electron spectroscopy and related phenomena Vol. 185; no. 11; pp. 441 - 447
• Main Authors: Srour, W., Tejeda, A., Nicolaou, A., Le Fèvre, P., Bertran, F., Taleb-Ibrahimi, A., Malterre, D.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-11-2012; Elsevier
• Subjects: Analogies; Band structure of solids; Bands; Mathematical analysis; Photoemission; Physics; Spectra; Spots; Symmetry; 61.05.jh; 68.47.Fg; 73.20.At71.18.+y; 68.37.Ef; 79.60.-i
• ISSN: 0368-2048; 1873-2526
• DOI: 10.1016/j.elspec.2012.08.005

► There is a qualitative link between photomission matrix elements and LEED. ► Diffracted and PES intensities in k space of Si(111)-(7×7) behave similarly. ► Diffracted and PES intensities as a function of E in vicinals behave similarly.
A direct comparison between photoemission measurements and band structure calculations is sometimes tricky. Matrix element effects may affect considerably the spectral weight of the electronic states and prevent the expected translational symmetry of the band structure from being observed. We show how matrix element effects can be qualitatively described to a certain extent by making an analogy between photoemission and low energy electron diffraction. We have tested this approach in two superperiodic systems. We have first explained the intensity distribution in different Brillouin zones of a surface state in Si(111)-(7×7), where the surface state spectral intensity does not exhibit the (7×7) symmetry. We have also compared the LEED intensity of superperiodic LEED spots with the energy dependence of bulk bands on a facetted Si surface as measured by photoemission.