Characterization of wurtzite CdSe single crystal surfaces

• Different surface core level shifts (SCLSs) for the (101¯0) and (112¯0) surfaces of wurtzite CdSe compound.
• The SCLSs of the latter surface are very similar to those of zinc blende CdTe1−xSex(110).
• High-resolution XPS can be sensitive to the topography of the surface.

The surface core level shifts, the binding energy differences between the photoelectron spectra of surface and bulk atoms, have been measured for nonpolar (101¯0) and (112¯0) crystallographic planes of CdSe. It was found that the former surface has surface core level shifts of −0.42 for Se 3d and 0.38 eV for Cd 4d spectra. The latter one gave values of −0.33 for the Se 3d and 0.28 eV for the Cd 4d doublets. The origin of these shifts was suggested to be due to terraces of the surface, since the cleavage occurs along the [0001] direction.