The valence band structure of the ZnSe{001}-(2 × 1) surface as determined by angle-resolved photoemission spectroscopy

Abstract

The valence band structure of the (2 × 1) reconstructed surface of ZnSe{001} has been investigated using angle-resolved photoemission spectroscopy. The results of our analysis are consistent with the band structure of a previously proposed (2 × 1) Se dimer-terminated surface and showed that there may be three surface resonance states lying in the first 3 eV from the top of the valence band maximum which extend over most of the length of the Brillouin zone along the 〈110〉 direction. A fourth feature identified as a surface state was observed around the X̄ point at ∼ −5.8 eV. The gap surface state previously predicted for the Se dimer-terminated surface was barely resolvable and was found to lie just above the valence band maximum at the \\ ̄ gG point.