Oxide phosphors as thin-film electroluminescent materials

The possibility of practical thin-film electroluminescent (TFEL) displays using oxide phosphor emitting layers has been investigated with a single-insulating-layer device structure using a thick insulating ceramic sheet. Highluminance TFEL devices using rare earth- or transition metal-activated oxide phosphors consisting of binary, ternary and multicomponent oxide compounds are demonstrated. It is concluded that oxide phosphors are very promising as emitting layer materials for TFEL devices, because they can exhibit EL characteristics comparable with those of sulfide phosphors. It was found that various oxide phosphor TFEL devices can emit the three primary colors without the use of color filters. The emissions from the following highluminance oxide phosphor devices were found to be suitable for full-color displays: Ga2O:Mn, ZnGa2O4:Mn and Zn2SiO4:Mn for the green color and ZnGa2O4:Cr for the red color. In addition, a luminance of 592 cd/rn2 for yellow emission was obtained in a CaGa2O4:Mn TFEL device driven at 60 Hz. Keywords: Oxide Phosphor, Thin-Film Electroluminescent Device, Electroluminescence, Thin Film, Phosphor, Display, Flat Panel-Display, Oxide