This Small Business Innovation Research Phase I Project Spire proposes to develop zinc gallate (ZnGa2O4) as a thin-film host phosphor, and produce full color (red, green, blue) faceplates by selective ion implantation of recognized luminescent centers for this material, viz., Cr, Mn, Ga. Field emission displays (FEDs) based on cathodoluminescent (CL) phosphors are rapidly becoming the favorite embodiment for flat panel displays in America, and many efforts are underway to bring FEDs into the marketplace. However, due to their granular nature and limited operating lifetime, conventional sulfide-based powder phosphors compromise FED performance. Replacing powdered phosphors with sulfur-free, thin film oxide materials produced by physical vapor deposition can improve chromaticity, allow much finer definition, and reduce phosphor degradation while aiding in process automation to allow control of manufacturing costs. In parallel ARPA sponsored programs, Spire has used ion implantation in phosphors to demonstrate 50 fL (60 Hz) yellow with ZnS:Mn and 1 fL (60 Hz) blue with CaGa2S4:Ce for thin film electroluminescence; and 15 fL (1 mA/cm2) green with Zn2SiO4:Mn for thin film cathodoluminescence, all state-of-the-art brightness levels. The proposed program will demonstrate all three colors in adjacent lines on a single FED faceplate. Phase II will optimize phosphor chemistry and improve external efficiency by studying various texturing approaches to minimize waveguiding.
