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Dispersions of surface states on diamond (100) and (111)

1997; American Physical Society; Volume: 55; Issue: 16 Linguagem: Inglês

10.1103/physrevb.55.10841

1095-3795

R. Graupner, Manuela Hollering, A. Ziegler, J. Ristein, L. Ley, A. P. J. Stampfl,

Metal and Thin Film Mechanics

We present angle-resolved photoelectron spectra and surface state dispersions for the clean, 2\ifmmode\times\else\texttimes\fi{}1 reconstructed (111) and (100) surfaces of diamond. For the (100) surface a surface state is found in the gap of the projected bulk band structure around Y-bar, which has a binding energy of 2.7 eV at Y-bar (relative to the Fermi level) and a dispersion in the \ensuremath{\Gamma}-bar-Y-bar direction of 0.5 eV, consistent with theory. At \ensuremath{\Gamma}-bar a surface resonance is observed at 1.4 eV binding energy. No surface states were observed above the valence-band maximum. Our results on the (111) surface show a strongly dispersing surface state that reaches its maximum 0.5 eV below the Fermi level at K-bar. This result implies a gap of at least 0.5 eV in the surface electronic structure, which has consequences for the surface reconstruction in terms of a \ensuremath{\pi}-bonded chain model.