Investigation of ZnS passivated InP nanocrystals by XPS

ZnS passivated InP nanoparticles prepared by the TOP/TOPO method have been investigated by photoelectron spectroscopy with tunable synchrotron radiation. Based on the energy dependence of the electron escape depth, we present a method to characterize the core-shell nature of the sample structure, Energy tuning indicates that In is confined to the core of the particles while Zn is located in a surrounding shell. Computer simulation allows us to quantify these results and to extract average layer thicknesses.