CaAl2O4:RE3+(RE = Tb or Dy) phosphor powders were synthesized with different contents of activator ions Tb3+ and Dy3+ by using the solid-state reaction method. The effects of the content of activator ions on the crystal structure, morphology, and emission and excitation properties of the resulting phosphor particles were investigated. XRD patterns showed that all the synthesized phosphors had a monoclinic system with a main (220) diffraction peak, irrespective of the content and type of Tb3+ and Dy3+ ions. For the Tb3+-doped CaAl2O4 phosphor powders, the excitation spectra consisted of one broad band centered at 271 nm in the range of 220-320 nm and several weak peaks; the main emission band showed a strong green band at 552 nm that originated from the 5D4→ 7F5 transition of Tb3+ ions. For the Dy3+-doped CaAl2O4 phosphor, the emission spectra under ultraviolet excitation at 298 nm exhibited one strong yellow band centered at 581 nm and two weak bands at 488 and 672 nm. Concentration-dependent quenching was observed at 0.05 mol of Tb3+ and Dy3+ contents in the CaAl2O4 host lattice.

• 조신호(신라대학교 신소재공학과, 녹색융합기술센터) | Shinho Cho Corresponding author