초록

A none-rare earth elements-based Mn2+-doped MgAl2O4 green phosphor for LED applications was synthesized by a solid-statereaction method. X-ray diffraction analysis revealed that the synthesized phosphors have a spinel-type MgAl2O4 phase and anysecondary phase formed by the Mn2+ addition was not detected. The prepared MgAl2O4 : Mn2+ phosphors showed a singleintense broadband green emission in the range from 500 to 560 nm excited by near UV to visible blue light. The green emissionmechanism was found to be attributed to the spin-forbidden d-d transition (4T1(4G) → 6A1(6S)) of Mn2+ by a schematic investigation in terms of energy transfer in Mn2+ ion. As the Mn2+ concentration increased, the emission intensity increased up to 3.0 mol% and then decreased at higher concentrations as a result of concentration quenching, while the peak wavelengthcontinuously moved to the longer wavelengths. Dynamic light scattering (DLS) and field-effect scanning electron microscopy(FE-SEM) characterization showed the 3 mol% Mn2+-doped MgAl2O4 phosphor particles have an irregularly round shape anduniform size distribution with an average particle size of 1-2 μm.

키워드

MgAl2O4 : Mn2+ phosphors, Solid-state reaction, Green phosphors, Optical properties, LEDs

참고문헌(1)open

  1. [단행본] S. Nakamura / 1996 / The Blue Laser Diode: GaN Based Light Emitters and Lasers / Springer : 1 ~ 24