Nanoencapsulation of ZnS:Ag particulates with indium tin oxide for field emission displays

Cathodoluminescence degradation measurements showed that by applying a nanometer-scale indium tin oxide (ITO) coating on micron-sized ZnS:Ag particles, the degradation lifetime was dramatically improved. X-ray photoelectron spectroscopy (XPS) analysis showed that the Zn 2p3/2 and S 2p peaks of the electron beam irradiated ZnS:Ag were shifted to higher binding energies, which correspond to oxidized elements with respect to those found for the commercial ZnS:Ag particulates. The XPS analysis for the ITO coated ZnS:Ag showed a broadening of the Zn 2p3/2 and S 2p peaks, which were a convolution of several peaks. In this case, the Zn 2p3/2 and S 2p peaks corresponding to ZnS were still present together with another shoulder corresponding to the oxidized elements. This difference in the XPS results shows that the ITO coating reduced the degradation rate by slowing the surface chemical changes on the ZnS:Ag powder.