Cesium coating of thin-film zinc sulphide cold cathodes

Avalanche breakdown in polycrystalline ZnS thin films can produce cold cathode hot electron emission. The physical processes behind this phenomenon are not well understood, nor is the nature of the electron energy distribution inside the ZnS during breakdown. Lowering the work function of the emission surface by evaporation of elemental cesium is discussed. The increase in emission current is compared to that from a tungsten filament and …