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A novel ceramic synthesis technique, combustion synthesis, was explored to produce red‐emitting Cr3+‐doped Y3A15O12 and Eu3+‐doped Y2O3 phosphors with improved physical and luminescent properties. This technique involves the reaction of metal nitrates (oxidizers) and an organic fuel (urea, carbohydrazide, glycine) at 500°C. Resulting powders are well‐crystallized, with a large surface area and small particle size. The spectral energy distribution was observed using photoluminescence measurements. The effects of processing parameters such as type of fuel, fuelto‐oxidizer ratio, furnace temperature, and batch water content were studied. An increase in phosphor brightness with increasing reaction temperature was observed. Postreaction heat treatments (1000°, 1300°, and 1600°C) increased the luminous intensity of as‐synthesized powders. Residual carbon content and chromium site symmetry were investigated as possible explanations for the increase in brightness with increasing heat treatment temperature. By tailoring the reaction chemistry, the optimal conditions for producing the most luminescent phosphors have been identified.

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The synthesis and photoluminescence mechanism of ZnGa204:Mn 2 § are presented. Monitored at 450 nm, ZnGa204 exhibits an absorption band at 245 nm; monitored at 506 nm ZnGa204:Mn ~ § exhibits absorption bands at 245 and 283 nm. Under 254 nm excitation ZnGa204 exhibits a broad-band emission extending from 360 to 610 nm, peaking at 450 nm. This emission is gradually quenched, as a new band emerges, peaking at 506 nm, as Mn 2 § is incorporated into the lattice (Zn~_~Mn~Ga2Q), where x = 0.006 at maximum intensity. Activator sensitization and host-to-activator energy transfer are suggested.

ZnGa2Q and Znl_~Mn~Ga~O4 were investigated as potential low voltage cathodoluminescence phosphors for use in vacuum fluorescent displays. A low-voltage cathodoluminescence spectrophotometer was developed for phosphor characterization. Brightness was measured as a function of anode voltage (10 to 300 V). The effects of activator concentration, phosphor layer thickness, deposition process, and internal pressure were examined. The stability of these oxide phosphors in high vacuum and absence of corrosive gas emission under electron bombardment, offer advantages over commonly used sulfide phosphors.