The interface microscopy and spectroscopy on the cleavage surfaces of the In4Se3 pure and copper-intercalated layered crystals

Surface properties of In4Se3, In4Se3(Cu) crystals were studied. SEM, STM surfaces micro-and nanostructure, and XPS spectra were obtained for interface on the cleavage surfaces of crystals that have been exposed to air. The intense XPS lines, viz. Se 3d, In 3d, Cu 2p, C 1s, and O 1s were recorded in an expanded binding-energy scale. In each case Gaussian line shape analysis has been done to determine the exact peak positions and peak areas. Chemical shifts have been obtained for the binding-energy values of the XPS lines for Se, In, C, and Cu. The formation of In–In metallic and In–O oxidized bindings and corresponding phases on the cleavage surfaces of In4Se3 and Cu–In–Se bindings for In4Se3(Cu) intercalated crystals have been found. Phases formation was also observed by SEM and STM.