Effect of BaF_2 as the source of Ba component and flux material in the preparation of Ba_(1.1)Sr_(0.88)SiO_4:Eu_(0.02) phosphor by spray pyrolysis

摘要

The phosphor powders with the composition of Ba_(1.1)Sr_(0.88)SiO_4:Eu_(0.02) were prepared by spray pyrolysis. Barium fluoride and barium nitrate were used as the source materials of Ba component. Ba_(1.1)Sr_(0.88)SiO_4:Eu_(0.02) phosphor powders had broad excitation wavelength ranging from 220 to 460 nm irrespective of mole ratios of barium fluoride and barium nitrate. Ba_(1.1)Sr_(0.88)SiO_4:Eu_(0.02) phosphor powders had broad emission spectrum [between 470 and 600 nm and had the maximum peak intensity at 522 nm. Substitution of BaF_2 instead of some amount of barium nitrate improved the photoluminescence intensities of Ba_(1.1)Sr_(0.88)SiO_4:Eu_(0.02) phosphor powders. The maximum photoluminescence intensity of Ba_(1.1)Sr_(0.88)-SiO_4:Eu_(0.02) phosphor powders prepared from spray solution with barium fluoride and barium nitrate was about 595% of the phosphor powders prepared from spray solution without barium fluoride. The sky blue light emitting LED with prepared phosphor powders showed (0.1958 and 0.2719) on the CIE chromaticity diagram and luminous intensity of 1.68 cd.