DMF effect on the morphology and the luminescence properties of Y2O3:Eu3+ red phosphor prepared by spray pyrolysis

N,N-Dimethylformamide (DMF) was used as a drying control chemical additive (DCCA) in spray pyrolysis in order to improve the luminous properties of Y2O3:Eu particles. It was found that the addition of DMF to the spray solution containing citric acid (CA) and ethylene glycol (EG) greatly enhances the photoluminescence intensity as well as the morphology of Y2O3:Eu particles. According to BET analysis, the surface area of Y2O3:Eu particles prepared from the solution containing only the organic additives was not reduced, whereas, the surface area of the Y2O3:Eu particles prepared from the solution containing both DMF and organic additives was decreased gradually as increasing the concentration of DMF. From these results, it was concluded that the adding of DMF to the spray solution containing the organic additives is a very effective way to reduce the porosity of phosphor particles, keeping the spherical morphology. As a result, the densification of porous structure led to greatly improve the photoluminescence intensity of Y2O3:Eu particles under ultraviolet (254 nm) excitation. Finally, the prepared Y2O3:Eu particles with dense structure showed about 208% improved photoluminescence intensity compared with the particles which have a spherical shape but porous structure.