THE PREPARATION OF ZNS/MN ELECTROLUMINESCENT PHOSPHOR LAYERS BY IONIZED CLUSTER BEAM DEPOSITION

The ionized cluster beam (ICB) technique was used to prepare thin films with good crystallinity. It utilizes the high kinetic energy of aggregates of atoms ionized by electron bombardment and accelerated to the substrate by a negative applied voltage. The ICB method was used for the preparation of ZnS:Mn phosphor layers for electroluminescent (EL) devices. A double-fiber structure was observed for films without ionization at low substrate temperature, whereas a single-fiber structure was observed for films produced by ICB even at low substrate temperature, Ionization and acceleration were confirmed to have an effect on improving the crystallinity of thin films, i.e. an increase in grain size and enhancement of crystal orientation. The threshold voltage tended to decrease and the maximum luminance tended to increase when using the phosphor layers prepared by ICB in EL devices. This is possibly the first report of a ZnS:Mn phosphor layer prepared by ICB applied to double insulating type thin film EL devices.