Confirmation of Incorporation of Cu and Se Ions in Applied p- and n-Type-Doped Sb2S3 by Photoemission Spectroscopy

The effect of incorporating copper (Cu) and selenium (Se) ions into stibnite (Sb2S3) lattice was investigated using x-ray photoelectron spectroscopy (XPS). The incorporation of Cu and Se ions was verified by comparing the XPS spectra of the undoped (amorphous Sb2S3), doped (p and n-doped) and pure Se and Cu-acetate powders. The main photoelectron Cu 2p(1/2) (951.8 eV) and Cu 2p(3/2) (932.1 eV) lines derived from the Cu-doped and Cu-acetate powder samples were clearly observed, whereas in the undoped sample, none of the characteristic lines of Cu were detected. The Se Auger line (138.6 eV), the only line of Se which does not coincide with the lines of Sb and S, was successfully detected in an Se-doped XPS sample and the spectrum of pure Se, while Se in the undoped sample was not found. Further, the XPS measurements revealed the relative amounts of Cu and Se in antimony sulfide, as well as the oxidation state of copper incorporated into the matrix.