IMPROVEMENT IN AGING CHARACTERISTICS BY ZN DOPING OF ELECTRON-BEAM EVAPORATED SRS-CE THIN-FILM ELECTROLUMINESCENT DEVICES

Aging characteristics of electron-beam evaporated SrS:Ce thin film ele ctroluminescent devices have been improved by using a SrS:Ce and ZnS m ixture source pellet. For the Zn-doped device, luminance is maintained at more than 60% of the initial value and threshold voltage remains c onstant for more than 1000 hours of aging at 500 Hz drive. A rapid dec rease in luminance corresponds to a decrease in dynamic space charge, and is reduced by Zn doping. In contrast, a slow decrease in luminance is attributed to a change in the electron emission characteristics of phosphor-insulator interfaces.