I have XPS data of a semiconductor material I want to find the Valance band and Conduction band position. It is possible to calculate valance band and conduction band positions with XPS spectrum??
any specific literature as reference would be a great help
Thanks in advance
First of all, you need a semiconductor where the states of interest are accupied by electrons. It is normally found for the valence band (VB). Here, the most accurate way to compare your measured VB spectrum with the theoretical density of states as demonstrated by Waldrop and Grant (Appl. Phys. Lett. 68 (1996) 2879). The position might be influenced by the surface electric field (A. Rizzi, J. Vac. Sci. Technol. B 17 (1999) 1674).
The situation is more difficult for the conduction band, beacuse most semiconductors exhibit surface depletion region, i.e. the CB states are not occupied b electrons within the information depth (mean free length path of electrons). For a couple of semiconductore, however, in particular for indium containing compoundts, there might exist an electron accumulation layer. There, the CB states are filled up to the Fermi level. Then it becomes also possible to determine the CB minimum.(P.D.C. King et al., Appl. Phys. Lett. 91, 092101 (2007); V. Scherer et al., Appl. Phys. Lett. 100, 212108 (2012)).
You could do UV Photoelectron Spectroscopy. (XPS machines come with this option). Combining that will DRS will give you the approximate band edge positions.
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