BaWO₄:Dy<SUP>3+</SUP>,Eu<SUP>3+</SUP> 백색광 형광체의 발광 특성과 에너지 전달 효율

다국어 초록 (Multilingual Abstract)

Dy<SUP>3+</SUP>- and Eu<SUP>3+</SUP>-codoped BaWO4 phosphors for white light-emitting diode were synthesized with different activator ions via a solid-state reaction process. The structural, morphological, and optical properties of the BaWO₄:Dy<SUP>3+</SUP>,Eu<SUP>3+</SUP> phosphors were investigated as a function of Eu<SUP>3+</SUP> concentration at a fixed concentration of Dy<SUP>3+</SUP> ions. XRD patterns exhibited that all the synthesized phosphors had a tetragonal system, irrespective of the concentrations of Dy<SUP>3+</SUP> and Eu<SUP>3+</SUP> ions. The excitation spectra of the synthesized phosphors were composed of three intense bands centered at 251, 355, and 393 nm and several weak peaks. For the BaWO₄:Dy<SUP>3+</SUP>,Eu<SUP>3+</SUP> phosphors synthesized with 1 mol% of Eu<SUP>3+</SUP>, the emission spectra under ultraviolet excitation at 393 nm showed two strong blue and yellow bands at 485 and 577 nm corresponding to the ⁴F9/2 <SUP>6</SUP>H15/2 and ⁴F9/2 <SUP>6</SUP>H13/2 transitions of Dy<SUP>3+</SUP> ions, respectively and several weak bands in the range of 600–700 nm resulting from the 4f transitions of Eu<SUP>3+</SUP> ions. As the concentration of Eu3+ ions increased, intensities of the blue and yellow emission bands gradually decreased while those of the red emissions increased rapidly and the energy transfer efficiency from Dy<SUP>3+</SUP> to Eu<SUP>3+</SUP> ions was 95.3% at 20 mol% of Eu<SUP>3+</SUP>. The optimum white light emission with x=0.363, y=0.357 CIE 1931 chromaticity coordinates was obtained for the sample doped with 5 mol% Dy<SUP>3+</SUP> and 1 mol% of Eu<SUP>3+</SUP>.

목차 (Table of Contents)

• Abstract
• 1. 서론
• 2. 실험방법
• 3. 결과 및 고찰
• 4. 결론
• References