An XPS study of novel wide band gap Zn x Sr1- x S semiconductors

The chemical bonding of Zn and Sr atoms to S atoms for Zn _x Sr_{1- x} S thin films has been studied with x-ray photoelectron spectroscopy (XPS). XPS signals from S and Zn in Zn _x Sr_{1- x} S made it clear that phase transition occurs at about x = 0.3 and 0.85 which is in a qualitative agreement with x-ray diffraction (XRD) results. We also found from the splitting of S 2p_3/2 photoemission lines that the Zn _x Sri_{1- x} S for the intermediate composition range have two phases The chemical shifts are also discussed in conjunction with crystal phases.