PUB - Publikationen an der Universität Bielefeld

The electronic structure of the layered semiconductor WSe2(0001) along Delta is studied by spin resolved photoelectron spectroscopy using circularly polarized radiation from the BESSY 6.5 m NIM. The experiments have been performed in the highly symmetric setup of normal incidence and normal emission. The photon energies were varied between 8 eV and 17 eV. Our data give direct informations about the spin-orbit splittings Delta E-so in the valence bands: 0.45+/-0.1 eV, 0.32+/-0.1 eV. On the basis of a set of measured spectra, a symmetry resolved bandmapping is performed for the valence bands, which confirms a relativistic bandstructure calculation, The measured electron spin polarizations agree with the group theoretical prediction and prove the symmetry labelling derived from a labelled nonrelativistic bandstructure by using group theory to be correct. (C) 1999 Elsevier Science B.V. All rights reserved.