Angle-resolved photoemission of the Si(111) 7 × 7 surface

• Published in: Surface science Vol. 99; no. 1; pp. 28 - 33
• Main Authors: Houzay, F., Guichar, G.M., Pinchaux, R., Thiry, P., Petroff, Y., Dagneaux, D.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1980
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(80)90573-7

Angle-resolved photoemission measurements have been performed on (7 × 7) Si surfaces as a function of the photon energy between 21 and 87 eV at normal emergence for both s- and p-polarizations. A study of the emission as a function of the polar angle has also been done at hv = 52 eV. Two well defined structures are found at −1.8 eV and −0.8 eV below the Fermi level and are attributed to surface states. The −0.8 eV structure is found to be maximum at normal emission and to exhibit a strong p z character. These facts and the absence of a high density of surface states near E F appear to be uneasily compatible with a vacancy model and favour models involving a buckling of the surface.