Title
Deep red-emitting Ca14Al10Zn6O35:Mn4+ phosphors for WLED applications
Author
Jin Young Park, Jung Sik Joo, Hyun Kyoung Yang, Minseok Kwak
Year
2017
Journal
Journal of Alloys and Compounds
Abstract
Novel deep red-emitting Ca14Al10Zn6O35:Mn4+ (CAZ:Mn4+) phosphors were synthesized by a citrate sol-gel method. The X-ray diffraction patterns of CAZ:Mn4+phosphors confirmed their cubic structure after annealing at 1200 °C. The photoluminescence emission (PL) and excitation (PLE) spectra were measured to examine the emission richness of CAZ:Mn4+ phosphors. The PLE spectra of CAZ:Mn4+phosphor exhibited a broad band, between UV and blue regions, due to the charge transfer (CT) transition of Mn4+-O2- and 4A2g→4T2g, 4A2g→4T2g, 4A2g→4T2g of Mn4+ions. The results showed that the deep red emission peak of the CAZ:Mn4+ phosphor was located at 714 nm due to the 2Eg→4A2g transition of Mn4+ ion, which was effectively excited by 450 nm. The optimum concentration of Mn4+ ion in Ca14Al10Zn6O35 host lattice was found to be at 3 mol%. Using CAZ:3Mn4+ phosphors, white light-emitting diode (WLED) was fabricated. The CIE chromaticity coordinates of CAZ:3Mn4+ and fabricated WLED located at (0.709, 0.291) and (0.338, 0.396), respectively, resulting in the generation of warm white light for indoor illumination.
Instrument
FP-8500
Keywords
Photoluminescence, Fluorescence, Quantum yield, Color analysis, Thermal stability, Materials, LEDs