Gd2O3:Eu phosphor particles with sphericity, submicron size and non-aggregation characteristics

Gd2O3:Eu phosphor particles with red emission were directly prepared by a continuous spray pyrolysis process. Photoluminescence, morphology and crystallinity of the as-prepared and annealed particles were investigated. The particles prepared at 800 degrees C have sharp peaks of cubic phase Gd2O3, and the crystallinity of the cubic phase increased with increasing reactor temperature up to 1400 degrees C. The mean size of the particles increased from 0.35 to 1.2 mu m when the solution concentration was increased from 0.02 to 1 M. The Gd2O3:Eu particles absorbed excitation energy in the range from 220 nm to 300 nm, and the maximum excitation wavelength was near 255 nm, The optimum brightness was obtained at a doping concentration of 10 at.%. The main emission peak was 612 nm, resulting in a red emission. The red light was obtained at 600 degrees C when the prepared particles were excited by UV light. The maximum PL intensity was obtained at 1400 degrees C, and the pattern of the PL spectra of the particles was changed at 1600 degrees C. The PL intensity of the as-prepared particles at 1400 degrees C was increased by a factor of 1.1 in comparison with annealed particles. (C) 1999 Elsevier Science Ltd. All rights reserved.