Dual preparation of hydrophobic and hydrophilic BaWO4:Eu phosphors. (June 2016)

• Record Type: Journal Article
• Authors: Cho, Young-Sik; Huh, Young-Duk
• Is Part Of: Materials research bulletin. Volume 78(2016)
• Page Start: 58
• Page End: 63
• Publication Date: 2016-06
• Subjects: BaWO4:Eu -- Red-emitting phosphor -- Bilayer system -- Transparent display; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2016.02.020
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: Red-emitting BaWO4 :Eu phosphors were prepared in hexane-water bilayer system. The hydrophobic nanometer-sized BaWO4 :Eu phosphors were obtained in hexane. The hydrophilic micrometer-sized BaWO4 :Eu dendrites were obtained in water. Abstract: BaWO4 :Eu phosphors were prepared by performing a solvothermal reaction in a water–hexane bilayer system. A barium oleate (and europium oleate) complex was obtained in hexane via a phase transfer reaction involving Ba 2+ (and Eu 3+ ) ions in an aqueous solution of sodium oleate. The outer surfaces of the nanometer-sized BaWO4 :Eu phosphors were capped by the long alkyl chain of oleate; therefore, the hydrophobic nanometer-sized BaWO4 :Eu phosphors preferentially dissolved in the hexane layer. The micrometer-sized BaWO4 :Eu phosphors were obtained in the water layer. The BaWO4 :Eu phosphors prepared in hexane and water yielded sharp strong absorption and emission peaks at 464 and 615 nm, respectively, due to the 7 F0 → 5 D2 and the 5 D0 → 7 F2 transitions of the Eu 3+ ions. The BaWO4 :Eu phosphors are good candidate red-emitting phosphors for use in InGaN blue-emitting diodes, which have an emission wavelength of 465 nm.