A Mg2+-Ge4+ substituting strategy for optimizing color rendering index and luminescence of YAG: Ce3+ phosphors for white LEDs

Journal Article · Thu Feb 15 00:00:00 EST 2018 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2017.10.019· OSTI ID:22805399

Jiang, Lipeng; Zhang, Xiyan; Tang, He; Zhu, Shiqi; Li, Qingxi; Zhang, Wenmin; Mi, Xiaoyun; Lu, Liping; Liu, Xiuling ^[1]

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1. School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (China)

Highlights: • Mg{sup 2+}-Ge{sup 4+} ion pairs can partially substitute the Al{sup 3+} ions of YAG successfully. With the substitution, the garnet crystal structure remains unchanged. • With increasing Mg{sup 2+}-Ge{sup 4+} ions concentrations, the emission spectra show a progressive red-shift, from 528 to 552 nm (about 24 nm). • In white LEDs, with increasing Mg{sup 2+}-Ge{sup 4+} ions concentrations, the CCT decreased gradually from 6798 to 3261 K and the CRI increased from 76.5 to 89.3. - Abstract: Mg{sup 2+}-Ge{sup 4+} ions substituted YAG: Ce{sup 3+} phosphors (Y{sub 3}Al{sub 5-2x}Mg{sub x}Ge{sub x}O{sub 12}: Ce{sup 3+}) were prepared by high temperature solid state reaction method. X-ray diffraction (XRD), Scanning election microscope (SEM), Photoluminescence (PL) spectra and so on were used to characterize the samples. The effects of Mg{sup 2+}-Ge{sup 4+} concentrations on the morphology, structure, luminescence properties, fluorescence lifetime and white LED performance of YAG: Ce{sup 3+} phosphors were studied in detail. The results indicate that Mg{sup 2+}-Ge{sup 4+} ion pairs can partially substitute the Al{sup 3+} ions of YAG successfully. With the substitution, the garnet crystal structure remains unchanged. However the emission spectra show a progressive red-shift, from 528 to 552 nm (about 24 nm). The lifetime decreased rapidly from 84 to 26 ns. In particular, the correlated color temperature (CCT) decreases gradually from 6798 to 3261 K and the color rendering index (CRI) increases from 76.5 to 89.3 with the increasing of the incorporation content of Mg{sup 2+}-Ge{sup 4+} ion pairs.

• OSTI ID: 22805399
• Journal Information: Materials Research Bulletin, Vol. 98; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM IONS
CERIUM IONS
COLOR
CONCENTRATION RATIO
CRYSTAL STRUCTURE
EMISSION SPECTRA
FLUORESCENCE
GARNETS
GERMANIUM IONS
ION PAIRS
LIGHT EMITTING DIODES
MAGNESIUM IONS
MORPHOLOGY
NEODYMIUM LASERS
OPTIMIZATION
PHOSPHORS
PHOTOLUMINESCENCE
RED SHIFT
SCANNING ELECTRON MICROSCOPY
TEMPERATURE RANGE 0400-1000 K
X-RAY DIFFRACTION