Angle-Resolved Photoelectron Spectroscopy on CdTe(100) c(2×2)

K.-U. Gawlik, J. Brügmann, S. Harm, R. Manzke, M. Skibowski Institut für Experimental Physik, Universität Kiel, Olshausenstr. 40-60, 24098 Kiel, Germany B.J. Kowalski and B.A. Orłowski Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa, Poland

Received: June 1, 1993

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The CdTe(100) c(2×2) surface prepared by ion bombardment and annealing was investigated by angle-resolved photoemission spectroscopy using synchrotron radiation with photon energies between 8.5 eV and 32 eV. The bulk band structure was determined along the ΓΔX-direction normal to the surface measuring energy-distribution curves. The results are compared with a theoretical valence band structure assuming free-electron-like final states in connection with k-conservation. For further comparison we calculated the final states by the pseudopotential method and analyzed the results in form of structure plots. In this way, most of the dispersing maxima in the normal emission spectra can be explained. For this mode of photoelectron spectroscopy the resulting dispersion must be due to the component of the Bloch wave vector normal to the surface, k⊥, keeping surface related structures at a fixed binding energy position Eb. The lack of dispersion for five structures along ΓΔX gives experimental evidence for their surface origin.

DOI: 10.12693/APhysPolA.84.1093 PACS numbers: 73.20.At, 79.60.Bm