The blue phosphor Sr2CeO4 synthesized by Pechini's method

Blue emitters are very attractive research subjects because of their possible industrial applications as phosphors for field emission displays. Recently, a blue phosphor, Sr2CeO4, was identified by a combinatorial materials synthesis technique. This material was further synthesized using the chemical coprecipitation method and the decomposition of acetates, carbonates and oxalates in a tedious procedure. In this work, we present the use of Pechini's method as an alternative for the synthesis of this promising material. When the precursor, (Sr/Ce) polymer citrate-ethylene glycol, was fired at 850 degreesC for 2 h, a mixture of Sre(2)CeO(4) and SrCeO3 (inactive) was obtained, whereas the amount of Sr2CeO4 was increased by further heating at 1100 degreesC for 2 h in an oxygen atmosphere, as shown by the diffraction pattern. The excitation spectra present two broad bands with maxima at 294 and 344 nm and the emission spectrum has a broad band (half width similar to 80 nm) centered at similar to 475 nm. The unusually long lifetime of the compound fired at 1100 degreesC of similar to0.04 ms is in good agreement with literature data. In conclusion, the blue phosphor material Sr2CeO4 synthesized at 1100 degreesC in an oxygen flux has comparable or even better emitter properties than that prepared over several days and/or at higher temperatures. The method is very attractive for industrial purposes. (C) 2001 Elsevier Science B.V. All rights reserved.