Photoemission study on the valence band of a β-FeSi2thin film using synchrotron radiationElectronic supplementary information (ESI) available: Core-level UPS spectra for Fe 3p and Si 2p, and the spectral differences for on- and off-resonance and for before and after resonance at the Fe 3p core excitation. See DOI: 10.1039/c0dt01832e

Resonant and constant-initial state photoemission spectroscopies using synchrotron radiation were applied to investigate the valence-band electronic structure of a semi-conducting β-type iron-disilicide (β-FeSi2) thin film. The results clearly indicated that the component elements, iron (Fe) and silicon (Si), contribute differently to the valence band features; the Fe 3d orbitals mainly concentrate in the top region of the valence band while the Si 3s and 3p orbitals spread over the wide region of the valence band. The β-FeSi2thin film showed a typical p-type semi-conducting nature with a work function of 4.78 eV. The β-FeSi2film showed the Fe M1VVAuger lines around the kinetic energy of 88 eV. It would be expected from these observations that there exist strong interactions between iron and silicon atoms in the β-FeSi2film resulting in orbital mixing and band formation. [ABSTRACT FROM AUTHOR]