NSF Award
9615987
Spire Corporation Ward Halverson This Small Business Innovation Research (SBIR) Phase II project will develop zinc gallate (ZnGa2O4) as a thin-film phosphor and produce full color faceplates by selective ion implantation of luminescence centers. Field emission displays (FEDs) based on cathodoluminescent phosphors are promising alternatives to active matrix liquid crystal displays; however, conventional sulfide-based powder phosphors compromise FED performance due to their granular nature, current-saturation characteristics, and limited operating lifetime. Replacing powdered phosphors with sulfur-free, thin film oxide materials can improve chromaticity, allow much finer definition, and increase phosphor lifetime, while reducing manufacturing costs. Phase I demonstrated bright red and green cathodoluminescence (CL) in sputter-deposited ZnGa2O4 which was ion implanted with europium and manganese; and bright blue CL was found from "self-activated" (Ga-rich) zinc gallate films. Phase II will optimize phosphor preparation, ion implantation and annealing, and increase external luminous efficiency by minimizing light-guiding in the thin-film phosphor. Organometallic chemical vapor deposition of ZnGa2O4 will be compared to sputter-deposition of the thin film phosphor host. A wider range of activator and co-activator ions and annealing schedules will be investigated. Multi-colmr phosphor faceplates will be fabricated and demonstrated in an operating FED device. Flat, field emission displays with high luminance, wide color gamut, high electrical efficiency, and long operating life will find applications in computer terminals, lap-top computers, instrument panels, navigational aids, and consumer electronics from cellular telephones to television sets.
