Preparation and Characterization of Zinc Sulfide Phosphors Coated with Barium Titanate Using Sol‐Gel Method

Abstract

A study has been carried out to prepare ‐coated phosphors utilizing a sol‐gel technique with mixed solutions of titanium alkoxides and barium alkoxides and acetate in various solvents. The precursor gel of prepared by the hydrolysis of iso‐propoxides of barium and titanium in iso‐propylalcohol transformed to crystalline at a low temperature of 550°C. Coating was carried out by heating the precursor gel containing phosphors in air at 450°C for 5 h, followed by heating in nitrogen‐flowing atmosphere at 570°C for 10 h in order to prevent phosphors from being oxidized. However, the heat‐treatment in nitrogen flowing atmosphere depressed the electroluminescent intensity because of oxygen defects in . It was found that annealing in air at 400°C for 5 h gives rise to the brightest phosphors.