Cathodoluminescent properties of coated SrGa2S4:Eu2+ and ZnS:Ag,Cl phosphors for field emission display applications

Field emission displays (FED) operate at lower voltages and significantly higher current densities than cathode ray tubes (CRTs). This makes it advantageous to consider how to adapt conventional CRT sulfur based phosphors, which have the highest luminescent efficiency, but which unstable under high electron bombardment, to FED applications. Thus to protect these phosphors from degradation it is necessary to develop thin layer coatings of stable materials, such as MgO, In2O3 or polyphosphate. The goal of this study is to investigate the influences of these coatings on the cathodoluminescent properties of the blue phosphor, ZnS:Ag,Cl; and the green phosphor, SrGa2S4:Eu2+.