The surface and bulk composition of Cu(2)ZnSn(Se(x)S(1-x))(4) (CZTSSe) monograin powders were investigated by X-ray photoelectron spectroscopy (XPS). The concentration depth profiling of CZTSSe monograin powders was obtained by Ar(+) ion etching. According to the XPS spectra of CZTSSe monograin powder, the binding energies of Zn 2p(3/2), Cu 2p(3/2), Sn 3d(5/2), S 2p(3/2) and Se 3d(5/2) core levels after surface cleaning are located at 1021.6 eV, 932.4 eV, 486.1 eV, 161.5 eV, 53.9 eV, respectively. From XPS depth profile analysis. Cu deficiency and the excess of chalcogenides on the powder crystals surface were observed. (C) 2010 Elsevier B.V. All rights reserved.