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Y 2 O 2 S:Eu Red Phosphor Powders Coated with Silica
Author(s) -
Jean JauHo,
Yang SzuMing
Publication year - 2000
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2000.tb01492.x
Subject(s) - tetraethyl orthosilicate , phosphor , materials science , fourier transform infrared spectroscopy , sol gel , scanning electron microscope , amorphous solid , transmission electron microscopy , hydrochloric acid , dynamic light scattering , analytical chemistry (journal) , nuclear chemistry , chemical engineering , mineralogy , nanoparticle , chemistry , nanotechnology , chromatography , crystallography , metallurgy , composite material , optoelectronics , engineering
Y 2 O 2 S:Eu red phosphor powders were coated with silica (SiO 2 ), using sol–gel and heterocoagulation techniques. Phosphor powders were dispersed in ethanol with tetraethyl orthosilicate and water. Hydrochloric acid was used to catalyze the sol–gel reaction, and an amorphous film 10–20 nm thick was observed via transmission electron microscopy (TEM). Colloidal SiO 2 powders 10–70 nm in size were used, and the SiO 2 powder coating was made by controlling pH values in the range of 4.5–8, in which a negatively charged surface of SiO 2 powder and a positively charged surface of red phosphor powder were formed. Then, SiO 2 powders were adsorbed electrically onto the phosphor powder surface, as evidenced by TEM, dissolution, and zeta potential measurements. Chemical bonding in the coating was studied using electron spectroscopy for chemical analysis and Fourier transform infrared spectroscopy.