ELECTROLUMINESCENT AND CATHODOLUMINESCENT PROPERTIES OF ZNS-CU,MN AND ZNS-CU,TB THIN-FILMS

The electroluminescent (EL) and cathodoluminescent (CL) characteristics of ITO-ZnS:Cu,Mn(Tb)-Al DC EL thin films were investigated. The experimental results showed that efficient resonant energy transfer takes place from self-activated ZnS and Cu centers to Mn ions resulting in high luminance of ZnS:Mn,Cu cells. EL properties of ZnS:Cu,Tb cells can be explained on the basis of the direct impact excitation model, while the energy transfer mechanism makes a negligible contribution to the excitation process. This accounts for the comparatively low EL luminance of Tb-doped cells.