IMPROVEMENT OF LOW-VOLTAGE CATHODOLUMINESCENT PROPERTIES OF ZINC-SULFIDE PHOSPHORS BY SOL-GEL METHOD

The phosphors used in conventional cathode rag. tubes (CRTs) are diffi cult to use at voltages lower than 500 V, because of charge buildup on their surface. To overcome this drawback a ZnS:Ag,Cl phosphor was coa ted with a very thin In2O3 conductive layer by the sol-gel method usin g tri-iso-propoxyindium. Properties of the cathodoluminescence at volt ages ranging from 50-500 V were studied and compared with those of the as-received ZnS:Ag,Cl phosphor. It was found that the luminance of th e In2O3-coated phosphor was far better than that of the as-received ph osphor when they were excited using an electron beam with an energy of less than 500 eV. Furthermore, the aging characteristics of the catho doluminescence showed marked improvement.