Comparative analysis on the photoluminescence properties of Cs2BF6:Mn4+ (B = Ge,Si, Zr,Ti) red phosphors for WLEDs |
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| Authors: | Manman Liu Peipei Dang Yi Wei Sisi Liang Guofeng Liu Aifang Geng Hongzhou Lian Jun Lin |
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| Affiliation: | 1. State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, P. R. China
College of Chemistry and Engineering, Changchun University of Science and Technology, Changchun, P. R. China;2. State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, P. R. China;3. College of Chemistry and Engineering, Changchun University of Science and Technology, Changchun, P. R. China |
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| Abstract: | A series of Cs2BF6:Mn4+ (B = Ge, Si, Ti, Zr) red phosphors were synthesized by a precipitation-cation exchange route. The phase purity, morphology, and constituent were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical properties were investigated by photoluminescence (PL) spectra and high-resolution PL. Temperature-dependent PL examination at the range of both 273-573 K and 10-300 K was performed to investigate the emission mechanism of Mn4+ in these fluorides. The intensity for both zero-phonon lines (ZPLs) and vibration coupled emission of Mn4+ in these four systems with different crystal structures was investigated systematically. These phosphors present bright red emission under blue light (467 nm) illumination, among which Cs2GeF6:0.1Mn4+ shows the highest emission intensity with ultrahigh quantum efficiency of 94%. The white light-emitting diodes (WLEDs) fabricated with this sample, blue InGaN chips and commercial YAG:Ce3+ phosphor exhibited high luminous efficacy beyond 100 lm/w with high color rendering index (~88.6) and low color temperature (~3684 K). |
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| Keywords: | optical materials/properties phosphors photoluminescence |
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