Angle-dependent photoelectron spectroscopy has been used to study some details of the chemistry at the interface between indium-tin-oxide, deposited by argon plasma sputtering, and poly(p-phenylene vinylene). We find chemical species corresponding to different oxidized states of poly(p-phenylene vinylene) and we discuss their assignment with reference to those produced in photo-oxidation experiments. (C) 1998 Elsevier Science S.A.