JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Zongjie Zhang,Liangling Sun,Balaji Devakumar,G. Annadurai,Jia Liang,Shaoying Wang,Qi Sun,Xiaoyong Huang
In this paper, a series of Eu 3+ -activated double-perovskite Ca 2 LaTaO 6 (abbreviated as CLT: x Eu 3+ ; x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, and 0.8) red-emitting phosphors have been successfully synthesized via the conventional high-temperature solid-state reaction method. These samples were characterized by X-ray diffraction, Rietveld refinement , field-emission scanning electron microscope , elemental mapping, energy-dispersive spectrum, room-temperature photoluminescence , decay lifetimes, quantum efficiency, CIE color coordinates, and temperature-dependent emission spectra . Interestingly, under blue excitation into the 7 F 0 → 5 D 2 transition of Eu 3+ at 466 nm, the CLT: x Eu 3+ phosphors could emit bright red light corresponding to the 5 D 0 → 7 F J (J = 1, 2, 3, 4) transitions. Their luminescence properties have been investigated as a function of the Eu 3+ ions concentration . It was found that the CLT:0.4Eu 3+ sample exhibited the strongest emission intensity, and the concentration quenching effect was caused by the dipole-dipole interaction among Eu 3+ activators. Impressively, the emission intensity of the as-prepared CLT:0.4Eu 3+ phosphors was about 4.3 times higher than the commercial Y 2 O 3 :Eu 3+ red phosphors. Moreover, the CLT:0.4Eu 3+ sample had excellent CIE color coordinates of (0.665, 0.334) and supereminent color purity of 95.3%. Notably, the study on temperature-dependent emission spectra of the CLT:0.4Eu 3+ sample revealed its good thermal stability and color stability at high temperatures. These excellent photoluminescence properties of CLT:0.4Eu 3+ phosphors indicated their promising application potential in white light-emitting diodes as blue-light-excitable red phosphors.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Ying Lv,Siting Fan,Yujie Zhao,Yu Liu,Xiaohang Zhang,Jie Zhao,Jian Yu
Single-component white phosphor is highly desirable to obtain efficient and stable white light-emitting diodes (w-LED). In this paper, a series of Bi 3+ , Tb 3+ , and Eu 3+ doped Ca 3 LuAl 3 B 4 O 15 (CLAB) luminescent materials were successfully prepared. The structure, morphology, and optical properties of samples were characterized by X-ray diffractometer, scanning electronic microscopy, and fluorescence spectroscopy , respectively. The synthesized phosphor exhibits strong blue band emission from Bi 3+ and intense characteristics line emission from Tb 3+ and Eu 3+ under ultraviolet (UV) light excitation. The emission color can fine be adjusted by changing the doping content of the three activators. The warm white light of CLAB:0.5%Bi 3+ ,2%Tb 3+ ,0.75%Eu 3+ with CIE chromaticity coordinates of (0.3728,0.3166), a CCT of 3671 K, and a Ra index of 87 could be realized under UV light excitation. The fabricated w-LED by combining UV chip with CLAB:0.5%Bi 3+ ,2%Tb 3+ ,0.75%Eu 3+ shows excellent thermal stability after high-temperature aging test, implying its promising application in single-phosphor-converted warm w-LEDs.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Kuichen Li,Yue Xu,Zehao Jin,Lili Wang
To achieve large-scale commercialized use of white quantum dots light-emitting diodes (WQLEDs). It is vital to find environmentally friendly and inexpensive luminescent materials without rare earth participation. In this paper, the zinc sulfide quantum dots with different Cu 2+ contents (ZnS:Cu-QDs) were prepared by one-step hydrothermal method , the quantum yield can reach 27.65 % and the thermal decomposition temperature is 610 ℃. Furthermore, the luminescence mechanism of ZnS:Cu-QDs was explored. The wavelength-tunable WQLEDs were fabricated. The WQLEDs exhibit from standard white light to warm white light with a relative colour temperature in the range of 4764–3851 K. The as-prepared WQLEDs from ZnS:Cu0.8 %-QDs show a warm white light with International Commission on Illumination (CIE) coordinates of (0.4009, 0.4265), colour rendering index (CRI) of 72.1, and the correlated colour temperature (CCT) of 3851 K at an input voltage of 3.4 V. This research provides a promising way for achieving WQLEDs by single phase quantum dots without the addition of rare-earth elements.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 23
·8259
·
IF 4.927
Ping Gao,Suwen Cheng,Jiaxin Liu,Junjie Li,Yanyan Guo,Zhengtao Deng,Tianshi Qin,Aifei Wang
Lead-free all-inorganic halide materials with different Mn2+-based crystal structures (Cs3MnBr5and CsMnBr3) were obtained using a convenient synthetic method. Cs3MnBr5had a bright green emission (522 nm), with a unique single-exponential lifetime (τavg= 236 µs) and a high photoluminescence quantum yield (82 ± 5%). A red emission was observed in the case of the CsMnBr3structure with a two-exponential fluorescence decay curve, and the lifetime was 1.418 µs (93%) and 18.328 µs (7%), respectively. By a judicious tuning of the synthetic conditions, a mixed phase of Cs3MnBr5/CsMnBr3was also produced that emitted white light, covering almost the entire visible spectrum. White-light-emitting diodes (WLEDs) with color coordinates (0.4269, 0.4955), a color temperature of (3773 K), and a color rendering index (68) were then fabricated using the as-prepared powder of mixed phases of Cs3MnBr5/CsMnBr3with a commercial UV LED chip (365 nm).Keywords:perovskite;Cs3MnBr5;manganese halide;phosphor;white LEDs
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2024
·Vol. 130
·期 4
·1-9
·
IF 2.5
Qian Di,Jin Yahong,Li Yanmei,Wu Haoyi,Hu Yihua
Phosphor-converted light-emitting diodes (pc-LEDs) with broadband near-infrared (NIR) emissions have garnered significant research interest. Their performance is primarily determined by the type of NIR phosphor used. Herein, a broadband NIR-emitting phosphor, Y 3 Sc 2 Al 3 O 12 :Cr 3+ , is synthesized. The blue-light excitation of the Y 3 Sc 2 Al 3 O 12 :Cr 3+ phosphor produces a broadband emission spectrum ranging from 640 to 1000 nm with a full width at half maximum (FWHM) of 113 nm. The NIR emission intensity maintains approximately 50% of the initial room-temperature intensity at 423 K. The structure–property relationship is also comprehensively studied. Encapsulating the as-obtained NIR phosphor into prototype pc-LEDs produces an NIR output power of 58.1 mW at a 1230 mA driving current and a photoelectric conversion efficiency of 3.5% at 30 mA. Finally, night-vision applications are implemented using the as-fabricated pc-NIR-LEDs device.
研究领域:
材料科学
·
光电子学
·
固态照明
·
红外技术
·
荧光粉化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·
IF 2.7
Jiaxin Gao,Mengxin Liu,Xinan Shi,Daocheng Pan
A high-quality electron transport layer (ETL) has an extremely profound impact on the performance of quantum dot light-emitting diodes (QD-LEDs). To date, ZnO nanoparticle thin films have been usually adopted as ETLs in high-performance QD-LEDs. However, because ZnO is an amphoteric oxide, ZnO nanoparticles are chemically unstable in air, and the quantum-sized SnO2 nanoparticles have great potential to resolve the stability issue of the ZnO nanoparticle ETL. In this work, we develop a ligand-assisted solvothermal precipitation method to prepare quantum-sized SnO2 nanoparticles. Short-chain butyric acid and butylamine are used as the binary ligands, and ethanol is used as the solvent. Under solvothermal conditions, hydrophobic SnO2 nanoparticles capped by butyric acid and butylamine will aggregate and form a white precipitate in ethanol. The SnO2 nanoparticles with a particle size of 3.6 nm exhibit an optical band gap of 4.23 eV. Based on the quantum size effect, the conduction band minimum position of the quantum-sized SnO2 nanoparticles is upshifted to −3.72 eV, which makes them suitable for use in QD-LEDs as the ETL, so that the electrons can be readily injected into the quantum dot emitting layer. As a result, QD-LEDs based on the quantum-sized SnO2 nanoparticles exhibit a maximum external quantum efficiency of 12.9%, revealing that the quantum-sized SnO2 nanoparticles have great potential for application in QD-LEDs as the ETL.
研究领域:
材料科学
·
纳米技术
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2025
·
IF 3.7
Yueyue Wu,Lan Liu,Zifan Li,Jiayi Xie,Zixin Wang,Guo Fang,Keyan Li,Zhenhui Tao,Xin Li,Fei Xiu,Juqing Liu
Graphical With the synergy of Mn 2+ and ODA codecoration, CDs with ultrabroadband and efficient yellow fluorescence in the solid state were synthesized through a simple one-step solvothermal process. These synthetic phosphors exhibit a production yield of 80%, an FWHM of 98 nm, and a solid-state quantum yield up to 62.8%, allowing for high-CRI white LEDs in green and health lighting. Exploiting environment-friendly and efficient phosphors is crucial to constructing high-quality and sustainable white light-emitting devices. Here, we demonstrate a facile and high-yield approach to synthesize Mn 2+ /octadecylamine (ODA)-codecorated carbon dots (CDs) with ultrabroadband and efficient yellow fluorescence in the solid state. The dots are prepared from anhydrous citric acid (CA), 1-ODA, and manganese acetate through a simple one-step hydrothermal process, with a production yield of 80%, a full width at half maxima (FWHM) of 98 nm, and a solid-state quantum yield up to 62.8%. Utilizing the synthetic CDs powder as a phosphor to directly coat on a blue light-emitting chip, the device exhibits warm white emission, with a high color rendering index (CRI) of 88, correlated color temperature (CCT) of 4215 K, and Commission International de l'Éclairage (CIE) coordinates of (0.33, 0.31), endowing great potential applications in green and health lighting.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES
·
2023
·Vol. 78
·期 10
·921-926
·
IF 1.8
Cong Liu,Junshen Xing,Zheng Liu,Wenlin Feng
BaSr 2 (PO 4 ) 2 : 4 %Eu 3+ , 4 % A ( A = Li + , Na + , K + ) phosphors were prepared by high-temperature solid-phase method. The crystal structure, photoluminescence properties, thermal stability, chromaticity coordinates, and fluorescence lifetime of the samples were investigated. The excitation and emission spectra of the samples are broadbands and the maximum peak of the emission spectrum is located at 619 nm. Among three charge compensators, the luminescence intensity is optimal for Li + co-doping case, and the quenching temperature of the typical sample is about 500 K. the fluorescence lifetime
τ
is 1469.6 ns, and the chromaticity coordinates exhibit a strong red emission. The present phosphor has a potential application for white light-emitting diodes (LEDs) under the near-ultra violet (n-UV) light excitation.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 11
·1568
·
IF 4.7
Yinbiao Shi,Xiaojia Su,Xiaoyan Wang,Mingye Ding
Inorganic CsPbX3(X = Cl, Br, I) perovskite quantum dots (PQDs) have attracted widespread attention due to their excellent optical properties and extensive application prospects. However, their inherent structural instability significantly hinders their practical application despite their outstanding optical performance. To enhance stability, an in situ electrospinning strategy was used to synthesize CsPbX3/polyacrylonitrile composite nanofibers. By optimizing process parameters (e.g., halide ratio, electrospinning voltage, and heat treatment temperature), all-inorganic CsPbX3PQDs have been successfully grown in a polyacrylonitrile (PAN) matrix. During the electrospinning process, the rapid solidification of electrospun fibers not only effectively constrained the formation of large-sized PQDs but also provided effective physical protection for PQDs, resulting in the improvement in the water stability of PQDs by minimizing external environmental interference. Even after storage in water for over 100 days, the PQDs maintained approximately 93.5% of their photoluminescence intensity. Through the adjustment of halogen elements, the as-obtained composite nanofibers exhibited color-tunable luminescence in the visible light region, and based on this, a series of multicolor anti-counterfeiting patterns were fabricated. Additionally, benefiting from the excellent water stability and optical performance, the CsPbBr3/PAN composite film was combined with red-emitting K2SiF6:Mn4+(KSF) on a blue LED (460 nm), producing a stable and efficient WLED device with a color temperature of around 6000 K and CIE coordinates of (0.318, 0.322). These results provide a general approach to synthesizing PQDs/polymer nanocomposites with excellent water stability and multicolor emission, thereby promoting their practical applications in multifunctional optoelectronic devices and advanced anti-counterfeiting.
研究领域:
材料科学
·
光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICS EXPRESS
·
2024
·Vol. 32
·期 17
·29817-29829
·
IF 3.2
Zongtao Li,Zongtao Li,Jiayong Qiu,Xiujuan Liu,Jiasheng Li
To address challenges in enhancing color uniformity and ambient contrast ratio (ACR) in RGB light-emitting diodes (LEDs) without losing efficiency, we developed a scattering-enhanced magnetic manipulation (SEMM) bilayer structure. The effect of the TiO2 scattering layer on improving the LED’s angular intensity non-uniformity (AIN) was studied by ray-tracing simulations and optimized by varying the particle concentration. The magnetic manipulation technique formed the microcolumns and magnetic chains of the Fe3O4 anti-reflective layer, which was optimized by adjusting Fe3O4 particle size, magnetic field strength, and Fe3O4 concentration. The resulting bilayered device significantly increased the ACR by 11.38 times and reduced AIN by 63% compared to conventional graphite-based LEDs, while maintaining high brightness and consistent color quality across angles. This marks a pioneering application of magnetic manipulation in enhancing LED display quality.
研究领域:
光学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Haoran Su,Xinyi Li,Dongze Li,Di Gao,Mengxue Zhang,Yufan Shang,Yanping Liu,Huiling Geng,Xiang Liu,Ruijin Yu
Thermal stability holds particular significance for phosphors intended for LEDs . Abnormal thermal quenching was successfully reached by strategic point defect engineering by inserting Frenkel defects and nonequivalent substitution defects in novel Sm 3+ ions doped Na-rich distorted double perovskite Na 1.5 La 1.5 TeO 6 phosphors. Its integral intensity at 420 K (115.03 %) was far higher than that of room temperature . Besides, the phosphors exhibited a pronounced orange-red emission peak at 644 nm when excited at 404 nm, which was ascribed to the 4 G 5/2 - 6 H 9/2 transition of Sm 3+ ions. The concentration quenching phenomenon resulting from dipole-dipole interactions was observed in the phosphors, and the optimal concentration of dopant Sm 3+ was determined to be 1 mol%. After calculation, it was surprising that the color purity values of all phosphors were not less than 99.9 %. Additionally, the internal quantum efficiency (IQE) reached 65.30 %, and the activation energy ( E a ) of Na 1.5 La 1.5 TeO 6 :1 mol%Sm 3+ was 0.570 eV. Meanwhile, the emission spectrum of the produced orange-red light emitting diodes (LEDs) exhibited a close correspondence with the absorption curves of various plant pigments (chlorophyll b , allophycocyanin, phycocyanin, phytochrome red and far red (P R and P FR )). The prepared white light emitting diodes (WLEDs) possessed low correlated color temperature (CCT) of 4769 K and as high general color rendering index (CRI, R a ) value as 91. In summary, the phosphors presented promising options for plant-cultivating LEDs and high CRI WLEDs based on their superior optical and thermal properties .
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2026
·
IF 3.8
Liang Yang,Jianwei Dao,Zihao Han,Zhihao Jiang,Yajie Deng,Taiping Han
Traditional white light-emitting diodes (LEDs) frequently exhibit cyan-gap deficiency, resulting in unbalanced emission spectrum that impedes the realization of full-spectrum lighting. Herein, a novel Ce 3+ -doped garnet phosphor CaY 2 HfAl 4 O 12 (CYHAO:Ce 3+ ) was successfully synthesized via a high-temperature solid-state reaction method. The crystal structure, luminescent properties, thermal stability, and WLED application performance of the phosphor were systematically investigated. X-ray diffraction (XRD) and Rietveld refinement results confirm that CYHAO:Ce 3+ crystallizes in a cubic garnet structure with space group Ia-3d. Under 446 nm blue light excitation, CYHAO:Ce 3+ exhibits a broad cyan emission band centered at ∼505 nm, which perfectly fills the cyan-gap of traditional WLEDs. The optimal Ce 3+ doping concentration is determined to be 0.02 mol. Concentration quenching mainly resulted from radiation reabsorption and electric dipole-electric dipole interactions. This phosphor exhibited strong thermal stability, retaining ∼73% of initial emission intensity at 423 K with an activation energy of 0.31eV. A WLED device fabricated by combining it with commercial CaAlSiN 3 :Eu 2+ phosphors and a 450 nm blue chip emitted warm white light with an excellent color rendering index (Ra = 92.8, R9 = 93.9, R15 = 91.7) and a correlated color temperature of 3507 K. These results demonstrate that CYHAO:Ce 3+ is a promising cyan phosphor for high-quality full-spectrum WLEDs with excellent color rendering performance.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）