Empty electronic states in low-energy absorbed current spectroscopy of NbSe2(0 0 0 1) surface

The fine structure of the experimental absorbed current spectra along the normal to a clean NbSe2(0 0 0 1) surface is interpreted theoretically. It is shown that the fine structure of absorbed current spectra is mainly due to the electronic structure of unoccupied high-level electronic states (above the vacuum level), which become occupied by electrons entering a solid. The predominant role of the bulk energy-band structure effects in the spectra formation is shown. In addition, a comparison to existing theoretical and experimental data is given.