- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Novel emission bands of Na2TiF6:Mn4+ phosphors induced by the cation exchange method
摘要： A series of Na2TiF6:xMn4+ samples were prepared by the cation exchange method. Visible QC behavior and the strongest ZPL peaks were observed for these samples. The characteristic of the visible QC behavior is that PL intensity at 620 nm is 1.61 times as high as PLE intensity at 476 nm. The mechanisms of these phenomena were discussed, and the color purity, crystal-field and nephelauxetic effect, the critical distance and the multipolar interaction for the samples were determined. The result shows that the Mn4+ ions are located at a strong crystal field and the concentration quenching of Mn4+ is from the quadrupole-quadrupole interaction. The slightly increase of nephelauxetic ratio causes the slightly blue shift of emission. The color-purity and chromaticity coordinates of the optimal sample suggests that the strongest ZPL makes its red emission with high color-purity. Thus, Na2TiF6:0.08Mn4+ is a potential red-emitting phosphor for blue light-based WLEDs.
关键词： Fluorides,Photoluminescence,Mn4+,Red emitting phosphor,Visible quantum cutting
更新于2025-09-23 15:23:52
-
Pressure effect on phosphor thermometry using Mg <sub/>4</sub> FGeO <sub/>6</sub> :Mn
摘要： This study examined the effect of ambient pressure on the luminescent lifetime of Mg4FGeO6:Mn phosphors in different morphologies. To evaluate the pressure sensitivity of phosphor in the form of particle, agglomerated particle and chemically bonded coating, samples including phosphor powder, pressed phosphor disc, and chemically bonded phosphor coating were fabricated and calibrated using a PMT-based measurement system for a pressure range of 20-200 kPa and a temperature range of 298-873 K. The results showed no obvious pressure effect on the lifetime of the chemically bonded Mg4FGeO6:Mn coating. However, the lifetime of the phosphor powder and pressed phosphor disc decreased as pressure increased. This pressure effect was most obvious for the pressed phosphor disc, which was further aggravated at higher temperatures. The atomic distance between manganese ion and other atomics reduced as pressure increased, which induced the movement of excited state in the configuration coordinate. Considering this dependency of pressure sensitivity on phosphor morphology, it is important to adopt the same fabrication procedure for calibration and temperature measurement using Mg4FGeO6:Mn. In addition, for in-flow measurement using Mg4FGeO6:Mn tracer particles, the influence of environmental pressure must be considered.
关键词： Phosphor thermometry,Lifetime,Mg4FGeO6:Mn,Pressure effect
更新于2025-09-23 15:23:52
-
Electronic structure and luminescent properties of Ce3+-doped Ba3Lu2B6O15, a high-efficient blue-emitting phosphor
摘要： A high-e?cient blue-emitting phosphor Ba3Lu2B6O15: Ce3+ was synthesized by three-step solid-state method. XRD Rietveld re?nement analysis reveals that Ba3Lu2B6O15 is of cubic Ia3(——) system, owning a high-symmetric layer structure with two regular LuO6 octahedrons and one BaO9 polyhedron. Density functional theory (DFT) calculation result indicates BLB is a kind of direct band-gap material with broad band-gap of ~5.10 eV. Ba3Lu2B6O15:Ce3+ phosphor exhibits a bright blue emission under UV excitation with high quantum e?ciency of > 90%, and the possible reasons are discussed basing on structural and spectral data. Because of its excellent luminescent properties, Ba3Lu2B6O15:Ce3+ could be a promising candidate as a blue phosphor for NUV LED devices.
关键词： Ce3+,Luminescence,Phosphor,Structure
更新于2025-09-23 15:23:52
-
Crystal structure and photoluminescence properties of novel garnet Y2-LaCaGa3ZrO12:xLn3+ (Ln = Eu and Tb) phosphors
摘要： A series of novel garnet Y2-xLaCaGa3ZrO12:xLn3+ (0 ≤ x ≤ 0.12; Ln = Eu and Tb) phosphors was prepared by a solid-state reaction. Their structural and photoluminescence properties were characterized by X-ray diffraction, Rietveld refinement, and photoluminescence spectroscopy. The studied Y2-xLaCaGa3ZrO12:xLn3+ phosphors crystallized in a cubic garnet crystal structure and Ia3ˉ d space group. The Eu3+- and Tb3+-doped Y2-xLaCaGa3ZrO12 phosphors exhibited strong red and green light emissions, respectively, and high emission color purity. With increasing Tb3+ content, the emitting color of the Y2-xLaCaGa3ZrO12:xTb3+ phosphors shifted to the green spectral region because of cross-relaxation among Tb3+ ions. The Y2-xLaCaGa3ZrO12:xLn phosphors are suitable for applications in white light-emitting diode and other optoelectronic devices.
关键词： Emission,Photoluminescence,Phosphor,Y2LaCaGa3ZrO12
更新于2025-09-23 15:23:52
-
Influences of sol-gel progress on luminescent properties of Li <sub/>1.0</sub> Nb <sub/>0.6</sub> Ti <sub/>0.5</sub> O <sub/>3</sub> :Eu <sup>3+</sup> red phosphor
摘要： Li1.0Nb0.6Ti0.5O3:3wt.%Eu3+ red phosphor was synthesized by sol-gel method. The influences of the pH value and the citric acid(CA)/ metal cations(M) ratio on the luminescent properties of the samples were discussed. The properties of the samples were characterized by X-ray diffraction(XRD) and photoluminescence spectroscopy, respectively. The results showed that the samples were consist of “M- phase”. Under the 466nm excitation, the orange emission at 592nm and the red emission at 612nm could be observed. The emission intensity increased with the increasing of pH value firstly and then decreased. The optimum pH value was 5.5. Moreover, the emission intensity decreased with the increasing of CA/M ratio. The relatively high emission intensity of the sample could be obtained when the CA/M was 3:1. Emission spectra and CIE coordinate of Li1.0Nb0.6Ti0.5O3:3wt.% Eu3+ were superior to commercial red phosphor Y2O3:Eu3+,which showed the red phosphor could have potential application in the White-LED field.
关键词： the red phosphor,Eu3+-doped,emission spectrum,Sol-gel method
更新于2025-09-23 15:23:52
-
[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Cathodoluminescent lamp for general lighting using carbon fiber field emission cathode
摘要： The prototype of cathodoluminescent bulb for general lighting with field emission cathode on the basis of carbon fiber is manufactured. The bulb comprises a high-voltage built-in AC-DC converter of the electric line voltage and a standard E27 cap. A high frequency converter is used to obtain high voltage. The anode voltage relative to the modulator is up to +20 kV; the cathode voltage is up to –4 kV; the current value is of the order of 1 mA. The voltage converter is located in the bulb cap and around the neck of the glass envelope.
关键词： cathode-ray-tube phosphor,carbon fiber,light sources,field emission cathodes,cathodoluminescence
更新于2025-09-23 15:22:29
-
Insights into anti-thermal quenching of photoluminescence from SrCaGa4O8 based on defect state and application in temperature sensing
摘要： Herein, a self-activated phosphor SrCaGa4O8 with excellent thermal stability was synthesized by high temperature solid state reaction method. It exhibited the broad emission range from 300 to 600 nm under 220 nm excitation, which may be caused by the intrinsic defects of host. Specifically, with the temperature increasing, the photoluminescence (PL) color changed from bluish to yellow-green and the maximum of PL intensity at 550 nm was obtained when reaching 493 K. From thermoluminescence curves and high temperature spectra, it was found that the anti-thermal quenching phenomenon could be dependent on the self-compensation of the carriers. Accordingly, the results of temperature-dependent intensity ratio and sensitivity show that SrCaGa4O8 may have potential in the optical temperature sensing.
关键词： Energy transfer,Self-activated phosphor,Optical properties,Anti-thermal quenching,Sensors
更新于2025-09-23 15:22:29
-
Synthesis and luminescent properties investigation of novel red emission phosphors Ca7Zn2(PO4)6: Re3+ (Re?=Eu, Sm and Pr)
摘要： A series of new red emission phosphors Ca7Zn2(PO4)6: Re3+ (Re3+ = Eu3+, Sm3+ and Pr3+) are synthesized by solid state reaction. The crystal structure and microstructure are systematically investigated by X-ray diffraction Rietveld structure refinement, scanning electron microscopy and energy dispersive spectrometer. The photoluminescence properties of Ca7Zn2(PO4)6: Re3+ (Re3+ = Eu3+, Sm3+ and Pr3+) are studied in detail. The results show that Eu3+ single doped Ca7Zn2(PO4)6 could emit red emissions with dominate peaks at 612 nm, 602 nm and 612 nm, respectively, which are attributed to the characteristic transitions (5D0-7F2, 4G5/2-6H7/2 and 3P0-3H6) of Eu3+, Sm3+ and Pr3+. The concentration dependent emission spectra of Ca7Zn2(PO4)6: Sm3+ are studied as well. A charge compensator Li2CO3 is added in Sm3+ doped Ca7Zn2(PO4)6 and the emission intensity is compared with the commercial red phosphor Y2O3:Eu3+. The room temperature fluorescence lifetimes of Ca7Zn2(PO4)6: Re3+ (Re3+ = Eu3+, Sm3+ and Pr3+) are measured and the average lifetimes are evaluated. Finally, the Commission Internationale de L'Eclairage chromaticity coordinates and their color purity are calculated.
关键词： Phosphor,Optical property,Luminescent property
更新于2025-09-23 15:22:29
-
The luminescent properties of GdAlO<SUB align="right">3:Tb<SUP align="right">3+</SUP> phosphors based on molten salts addition
摘要： The (Gd1–xTbx)AlO3 (x = 0–0.12) were obtained through ammonium bicarbonate co-precipitation technology. The pure-phase (Gd1–xTbx)AlO3 with good dispersion could be obtained at relatively lower temperature of 1,000°C. Under optimum UV excitation into 275 nm, the photoluminescence (PL) spectra display a series of 5D4–7FJ transitions of Tb3+ in (Gd1–xTbx)AlO3 system with the strongest green emission at ~546 nm. The overlapping between 8S7/2–6IJ intra f-f transition of Gd3+ and 4f8–4f75d1 transition of Tb3+ at 275 nm suggesting the Gd3+ → Tb3+ energy transfer, and the quenching contents of Tb3+ was found to be ~10 at%. The luminescent property of GdAlO3:Tb3+ phosphor could be further improved with molten salt incorporation. The optimal composition of molten salts was determined to be the mixture of NaCl/Na2SO4 (5 wt% NaCl), and the mass ratio of mixture molten salts to precursor was 2:1. The relationship between the luminescent property and molten salts composition were studied in detail.
关键词： energy transfer,GdAlO3:Tb3+ phosphor,molten salts,luminescent property
更新于2025-09-23 15:22:29
-
Enhanced optical properties of YAG:Ce yellow phosphor by modification with gold nanoparticles
摘要： In this paper methods of synthesis and characterization of cerium doped yttrium aluminum garnet (YAG:Ce) and the improvement of properties by in situ modification using gold nanoparticles are presented. YAG:Ce phosphor was obtained by cations co-precipitation followed by thermal treatment at 1000 °C, while for the development of the Au-YAG:Ce nanocomposites, the Turkevich method was used. The quality of the phosphor particles and composite has been structurally, morphologically and optically studied. It has been emphasized the obtaining of high purity phosphor and maintenance of the YAG:Ce garnet structure after modifying the phosphor surface with gold nanoparticles. Also, the use of gold nanoparticles has led to improvements in optical and morphological properties as a result of lowering the agglomeration trend. Improvement of optical properties makes possible the use of Au-YAG:Ce composite thus developing low energy light sources and with high performance.
关键词： YAG:Ce,Au-YAG:Ce composite,Optical materials,Phosphor
更新于2025-09-23 15:22:29