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Dehydrogenation-driven to synthesize high-performance Lu2Si4N6C:Ce3+- a broad green-emitting phosphor for full-spectrum?lighting
摘要: Green phosphor Lu2Si4N6C:Ce3+ (LSNC:Ce3+) shows an ideal feasibility to the near ultraviolet LED (n-UV LED) for “Full-Spectrum Lighting” (FSL). However, it is complex to synthesize pure Lu2Si4N6C phase. Herein, we prepared LSNC:Ce3+ via a novel dehydrogenation-driven high temperature solid-state reaction method, which distinctly optimized the morphology, and then significantly enhanced the photoluminescent performance of LSNC:Ce3+. The improving mechanism ascribed to the stepwise dehydrogenation of LuH3 which was beneficial to further shear LuH3 particles. The LSNC:Ce3+ phosphor obtained by the optimized process exhibits excellent thermal stability, and its external quantum efficiency is 57.3 %. Interestingly, the intensities of excitation peaks decrease at 375 nm while it increases at 425 nm gradually with the Ce3+ concentration. It is reasonably ascribed to the different ability of photo-ionization in different 5d levels. Finally, the constructed w-LED with the titled phosphor exhibits a well-distributed warm white light with high color rendering index (Ra = 96.6, R9 = 96, R12 = 82). It indicates that the LSNC:Ce3+ gives assistance to compensation for the “spectrum chasm” in blue-green region, as well as contributes to the improvement of Ra and R9, that is beneficial for full-spectrum lighting.
关键词: Carbonitride,n-UV LED,Reaction mechanism,Full-Spectrum,Green phosphor Lu2Si4N6C:Ce3+
更新于2025-09-23 15:23:52
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Effects of composition modulation on the structural and luminescence properties of Mn2+ doped Na2Mg1-xCaxSiO4 green-emitting phosphors
摘要: On the basis of the crystalline structural information that the matrix material has excellent physical-chemical stabilization, green-emitting Na2(Mg1-xCax)SiO4:Mn2+ (NMCS:Mn2+) phosphors were synthesized by a traditional solid-state method and systematically optimized, and their photoluminescence properties were studied. The luminescence properties of NMCS:Mn2+ phosphors as a function of Ca2+ concentrations were investigated. The structure of the as-prepared phosphors was identified by the X-ray diffraction (XRD) and the luminescent properties were characterized by the luminescence spectra, decay curve and CIE chromaticity coordinates. The emission peaks at 520nm generated by 4T1(4G)→6A1(6S) transition of the Mn2+ doped NMCS phosphors can provide a green component in the tri-color system. The emission intensity would be enhanced greatly by Ca2+-substitution and it can be observed that these emission peaks would shift to shorter wavelengths (blue-shift) with the increasing of Ca2+ content. The large enhancement of emission intensity and the shift of emission peaks due to Ca2+ substitution may provide a reference in the research of new type and more efficient phosphors for NUV-LEDs.
关键词: green phosphor,luminescence properties,Na2(Mg1-xCax)SiO4:Mn2+
更新于2025-09-23 15:21:21
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Synthesis, structure and optical properties of Erbium-doped Lithium Barium Phosphate
摘要: Li2BaP2O7 activated with Er3+ ions was prepared by the classic ceramic method and characterized by X-ray diffraction technique, IR, Raman and photoluminescence (PL) spectroscopies. The Li2BaP2O7: Er phosphors exhibited a monoclinic single phase structure with C2/c space group. A green and red emission lines dominate the spectrum upon excitation at 400 nm. The CIE-coordinate (x = 0.308, y = 0.512) were found in green light. Free ion parameters of the Er3+ ions in Li2BaP2O7 and the Judd–Ofelt parameters were calculated and they were used to explore the radiative parameters such as transition probability (AT), and branching ratios (β) related to the Er3+ emission transitions. The calculated 4S3/2 radiative life time around 0.198 ms is compared with the experimental value. The calculated quantum efficiency is about 42 %. Li2BaP2O7: Er can be considered as a novel green phosphor.
关键词: Erbium,green phosphor,Judd-Ofelt theory,optical spectroscopy
更新于2025-09-19 17:15:36