Nanofunctionalized Phosphor Particles for Advanced Display Applications

Abstract

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