Protective Silica Coatings on Zinc-Sulfide-Based Phosphor Particles

• Published in: Journal of the American Ceramic Society Vol. 85; no. 8; pp. 2128 - 2130
• Main Authors: Villalobos, Guillermo R., Bayya, Shyam S., Sanghera, Jasbinder S., Miklos, Robert E., Kung, Frederic, Aggarwal, Ishwar D.
• Format: Journal Article
• Language: English
• Published: Westerville, Ohio American Ceramics Society 01.08.2002; Blackwell; Wiley Subscription Services, Inc
• Subjects: coatings; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; particles; Physics; silica; Spray coating techniques; Crystal growth; Zinc sulfides; Inorganic compounds; Transition element compounds; Doping; Spray drying; Oxides; Silver additions; Experimental study; Particles; Sulfides; Nanometer scale; Field emission displays; Silicon oxides; Protective coatings
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1151-2916.2002.tb00419.x

A spray drying approach was used to apply 15‐nm‐thick SiO2 continuous coatings onto ZnS:Ag phosphor particles. A prehydrolyzed TEOS dip coating formula was used as the SiO2 precursor. The phosphor was mixed together with the precursor then atomized without allowing gelation to occur until the droplets containing the particles were in flight. The coating gelled and dried while falling through a graded heat zone. The dried coated particles were captured in a cyclone separator and heat‐treated to further densify the SiO2 coating. The coatings protected the phosphors while in service in field emission display (FED) devices.