Ultrabroadband red luminescence of Mn4+ in MgAl2O4 peaking at 651 nm
- 7 May 2020
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Dalton Transactions
- Vol. 49 (17), 5711-5721
- https://doi.org/10.1039/d0dt00931h
Abstract
Blue light pumped red luminescence with broadband and high photon-energy emission is highly desired for phosphor-converted white light-emitting diodes (pc-wLEDs), to achieve a high color rendering index and high luminous efficacy. Mn4+-doped red-emitting phosphors generally exhibit sharp vibronic emissions associated with the parity- and spin-forbidden E-2(g) -> (4)A(2g) transitions. In this paper, two abnormal luminescence behaviors were observed for Mn4+ in the MgAl2O4:Mn4+ spinel phosphor with a short wavelength emission band peaking at 651 nm. Firstly, the Mn4+ 2Eg -> (4)A(2g) transition exhibits ultrabroadband luminescence in MgAl2O4 and the large full-width at half-maximum (FWHM) is dependent both on the calcination temperature and on the partial substitution of Al3+ with Ga3+. Secondly, the thermal quenching behavior of the Mn4+ 2Eg -> (4)A(2g) luminescence in MgAl2O4 shows a dependence on its thermal treatment and preparation method. The Rietveld refinement and Raman results demonstrate that the variation in the FWHM of the luminescence spectra is a sum effect of structural ordering (i.e., isotropic displacement decrease of constituent atoms) and the Mg <-> Al anti-site disorder. A model for the observed varying thermal quenching of luminescence was tentatively proposed. The intrinsic thermal quenching temperature of Mn4+ luminescence in MgAl2O4 was found to be 390-400 K using the samples prepared by the co-precipitation and molten salt methods. The present work gives a novel perspective to understand the luminescence spectra of Mn4+ 2Eg -> (4)A(2g) transition.Funding Information
- National Natural Science Foundation of China (51902291, 51574205)
- China Postdoctoral Science Foundation (2019M662524, 2019M652574)
- Natural Science Foundation of Guangdong Province (2018B030311022)
- Japan Society for the Promotion of Science (16H06441, 19H02798)
- Russian Foundation for Basic Research (19-52-80003)
This publication has 52 references indexed in Scilit:
- Crystal field studies of the Mn4+ energy levels in the perovskite, LaAlO3Optical Materials, 2013
- Spectral analysis of RE3+(RE = Er, Nd, Pr and Ho):GeO2–B2O3–ZnO–LiF glassesJournal of Physics: Condensed Matter, 2008
- Synthesis and characterization of nano MgAl2O4 spinel by the co-precipitated methodCeramics International, 2007
- Predicting lattice parameter as a function of cation disorder in MgAl2O4spinelJournal of Physics: Condensed Matter, 2005
- Fluorescence properties of Mn4+ in CaAl12O19 compounds as red-emitting phosphor for white LEDJournal of Luminescence, 2005
- Synthesis of Mg–Al spinel powder via precipitation using ammonium bicarbonate as the precipitantJournal of the European Ceramic Society, 2001
- Structure of SpinelJournal of the American Ceramic Society, 1999
- Phase Relations and Lattice Constants in the MgO‐Al2O3‐Ga2O3 System at 1550°CJournal of the American Ceramic Society, 1997
- Luminescence and fluorescence line narrowing studies of Y3Al5O12:Mn4+Journal of Luminescence, 1986
- Luminescence of Mn ions in ordered and disordered LiAl5O8Journal of Luminescence, 1973