Morphology Of Phosphor Particles Research Articles

Influence of polymeric additives on morphology and performance of Y 2O 3:Eu phosphor synthesized by flame-assisted spray pyrolysis

Fine powder of cubic Y 2O 3:Eu phosphor was synthesized and simultaneously deposited on fused silica slides by low-temperature flame-assisted spray pyrolysis in premixed propane/air flames. By adding ethylene glycol and citric acid to the precursor solution, morphology of phosphor particles could be improved. The intensity of the photoluminescence (PL)-emission of the phosphor screens deposited by the modified technique, when excited by ultraviolet (UV)-light with the wavelength of 254 nm, did not exceed that of the screens deposited without the polymeric additives. However, in vacuum UV, phosphors produced with the addition of polymers perform significantly better than the ordinary “no-polymer” FASP-coatings.

Synthesis and characterisation of europium activated yttrium oxide fine powders

In order to prepare fine powders of red emitting Y 2O 3:Eu phosphors, the reagent simultaneous addition ( SimAdd) technique was developed and the influence of some preparative conditions on morpho-structural and optical properties of phosphors was studied. There was revealed that the precipitating reagent type and the pH of the precipitation medium influence on the photoluminescence (PL) properties as well as on the microstructure and morphology of phosphor particles. The SimAdd-technique enables us to prepare fine powders (<1 μm) of Y 2O 3:Eu phosphors with relatively good PL performances to be used in modern optoelectronic devices.

P‐51: Preparation of (Y,Gd)BO3:Eu3+ Phosphor with High Luminescent Efficiency by New Synthetic Method

AbstractTo improve the luminescent efficiency of conventional (Y,Gd)BO3:Eu3+ red‐phosphor for the plasma display panel (PDP), we have developed a new synthetic method such that the stoichiometric amount of boric acid is reacted with small‐sized and spherical (Y,Gd)2O3:Eu3+ phosphor oxides prepared by thermal decomposition of urea. The sol‐gel method using citric acid as a complex‐networking and fuel agents was also applied to compare the difference in luminescent efficiency under the vacuum ultraviolet (VUV) excitation depending on the synthetic methods. In this study, the most efficient composition of orthoborate was determined to be (Y0.64Gd0.31)BO3:0.05Eu3+. Orthoborate phosphor materials prepared by this new synthetic method have exhibited more effective VUV absorption in the range from 140 nm to 180 nm, and thus higher emissive brightness under the PDP operating condition than those of commercial phosphor and materials prepared in sol‐gel method. It is proposed that the present new synthetic method can improve crystalline purity and spherical morphology of phosphor particles and thereby the luminescent efficiency.

Morphology Control of BaMgAl10 O 17 : Eu Particles: The Use of Colloidal Solution Obtained from Alkoxide Precursor in Spray Pyrolysis

The morphology of phosphor particles was controlled by changing the precursor solution used in the spray pyrolysis. The colloidal and aqueous solutions were obtained using aluminum isopropoxide and aluminum nitrate as the source of aluminum. The characteristics of particles prepared from colloidal solution were compared with those of particles prepared from aqueous solution. The particles prepared from colloidal solution maintained their spherical structure and nonaggregation characteristics of as‐prepared particles even after post‐treatment at 1400°C while aggregation was observed to take place in the particles prepared from aqueous solution. The high thermal stability of particles prepared from colloidal solution was attributed to the stable intermediate, . For the highest crystallinity and brightness of particles, the optimum post‐treatment temperature was found to be 1200°C. The particles prepared from colloidal solution had higher crystallinity than those prepared from aqueous solution. © 2000 The Electrochemical Society. All rights reserved.