JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Shaokun Ling,Xiaoyan Qin,Chang chen,Kai Meng,Yifeng Yan,Junyun Ming,Sen Liao,Yingheng Huang,Lei Hou
Despite long-term development of LEDs, problems urgent to resolve is still existing. The most outstanding problem to tackle is luminescent stability at high temperature working situation. In this study, a novel type of β-NaYF 4 based phosphor incorporated with Eu 3+ and Tb 3+ is reported. A series of β-NaYF 4 :0.065Eu 3+ , x Tb 3+ ( x = 0.001, 0.002, 0.003, 0.004, 0.005) phosphors were synthesized by hydrothermal method . The sample β-NaYF 4 :0.065Eu 3+ ,0.002Tb 3+ possesses optimal luminescent property at room temperature. The mechanism of energy transfer from Tb 3+ to Eu 3+ ion is quadrupole-quadrupole interactions. The sample β-NaYF 4 :0.065Eu 3+ ,0.002Tb 3+ demonstrates zero thermal quenching (ZTQ) property at 303 K to 383 K. According to XRD and XPS characterizations, nonequivalent replacement between intrinsic ion Na + and Y 3+ were discovered, which finally leads to production of crystal defects. According to electron paramagnetic resonance (EPR) characterization and density functional theory (DFT) calculation, the type of crystal defect of β-NaYF 4 :0.065Eu 3+ ,0.002Tb 3+ is confirmed to be V Y vacancies which are the predominant defect of crystal. The depths and densities of defects were calculated according to data of thermoluminescence spectra (TL spectra). Crystal defects play the role of electrons traps that could store electrons. Electrons stored in traps will be excited to excitation state of Eu 3+ under the thermal stimulation to offset undesirable impact of thermal quenching (TQ), which leads to ZTQ property of the sample β-NaYF 4 :0.065Eu 3+ ,0.002Tb 3+ . The CRI and CCT of fabricated WLED are 3830 K and 84.1, respectively.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Cong Xiang,Jingyi Fang,Yanlin Huang,Zhuo Zheng,Hyo Jin Seo
Eu 3+ is not only a major red-emitting activator, but also an excellent spectral probe ion. This work reports the Eu 3+ -sites and luminescence in the cation-deficient perovskite tungstates, A-site deficient SrLa 2 (Mg 2 W 2 )O 12 [Sr 1/2 □ 1/2 La(MgW)O 6 ] and B-site deficient Sr 2 La 2 (MgW 2 )O 12 [SrLa(Mg 1/2 □ 1/2 W)O 6 ]. The 7 F 0 → 5 D 0 excitation spectra of Eu 3+ activators in two lattices were measured via pulsed dye laser. In SrLa 2 (Mg 2 W 2 )O 12 :Eu 3+ , there is only one 7 F 0 → 5 D 0 transition, which could be related to the Eu 3+ center on La 3+ sites; while, two 7 F 0 → 5 D 0 transitions in Sr 2 La 2 (MgW 2 )O 12 indicate Eu 3+ ions occupy Sr 2+ in addition to La 3+ , resulting in the luminescent centers related to heterovalent substitution defects. The different Eu 3+ sites make two phosphors exhibit different red luminescence properties. SrLa 2 (Mg 2 W 2 )O 12 :Eu 3+ shows higher luminescent efficiency and thermal quenching due to its regular distribution of the activators resulting in lower dispersion losses of the energy transfer. The experimental results show that rare earth ions occupy different crystallographic positions in A -site and B -site deficient perovskite oxides, and this microstructure can be important for the corresponding luminescent properties.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICA B-CONDENSED MATTER
·
2024
·
IF 2.8
Bingjie Han,Xinyu Chang,Haili Jiang,Yuhan Wang,Fengjun Tian,Kang Li,Sivagunalan Sivanathan,Xinghua Yang
Red inorganic phosphors are widely utilized in the field of artificial plant supplemental lighting. Nevertheless, their red light emission falls short of satisfying the plant's dual requirements for both deep-red and far-red light simultaneously. In this work, multiple red emission Sm 3+ and Sm 3+ -Mn 4+ activated CaGdMgNbO 6 (CGMNO) red phosphors were prepared by high-temperature solid-state reaction. The luminescence characteristics, thermal stability, energy transfer behaviour and optical temperature sensing properties were investigated. The 550–750 nm emission bands of CGMNO:Sm 3+ and CGMNO:Sm 3+ , Mn 4+ matched the absorption band of the plant. The inhibition of energy transfer between activated ions and the structural reconstruction of conduction band traps reveal the anomalous thermal quenching behavior of Sm 3+ ions at high temperatures. These results show that Sm 3+ -Mn 4+ co-activated CGMNO phosphors have potential applications in plant growth.
研究领域:
材料科学
·
植物学
✓ 已验证
产品关联
DOI
高影响因子
Laser & Photonics Reviews
·
2022
·Vol. 17
·期 3
·2200639
·
IF 10.947
Shuyang Bao,Yueyuan Liang,Cong Zhao,Luhan Wang,Xiaojuan Liang,Weidong Xiang
Solid-state white lighting applications with high brightness, low power consumption and long operating life have gradually dominated the modern industrial illumination market. For applications in white light-emitting diodes (WLEDs) and white-lighting laser diodes (WLDs), Phosphor-in-Glass (PiG), owing to its facile process, high efficiency and excellent chromaticity tunability, stands out as an optimal choice among various types of color converters. Currently, research in yellow-emitting Y 3 Al 5 O 12 :Ce 3+ (YAG: Ce) phosphors combined with different glass system has reached a mature stage and the poor illumination is a major bottleneck. Moreover, to realize high-quality white lighting, exploiting full-color PiGs is of great importance for its commercialization. Herein, the multicolour PiGs their successfully obtained by deliberately matching different color-emitting phosphors with the glass matrix. Glass composition selection rules for specific phosphors their proposed based on investigations of glass protection mechanism and the corrosion reaction between phosphors and glass matrix. In addition, an astonishing YAG: Ce PiG phenomenon (zero thermal quenching) is founded and discussed. As for practical applications, high-quality 5-W chip-on-board (COB) WLEDs their constructed by utilizing simple matches of colorful PiGs. Assembled WLDs modules also rendered a high-efficiency and stable lighting source. These results dramatically inspire the development of high-quality solid-state white lighting applications.
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
Xiaopeng Hu,Anlin Zhang,Rong Tang,Xiaoyue Jin,Junzhi Che,Xuan Ouyang,Chang Zhou,Lianwu Xie,Bin Deng,Ruijin Yu
A series of reddish-orange emitting Ca 2 InNbO 6 :Sm 3+ (CINO:Sm 3+ ) phosphors for white light-emitting diodes (w-LEDs) were synthesized using a high-temperature solid-state technique. The synthesized CINO:Sm 3+ phosphors are pure phases with monoclinic structures. The optimal Sm 3+ doping concentration is 0.02 mol, and concentration quenching is due to the dipole-dipole interaction. Upon 407 nm excitation, the as-prepared CINO:Sm 3+ phosphors exhibited strong reddish-orange emission around 602 nm, attributed to the 4 G 5/2 → 6 H 7/2 transition of Sm 3+ . Surprisingly, the CINO:Sm 3+ phosphors revealed an abnormal thermal quenching (ATQ) phenomenon, and when the temperature of the phosphors was raised to 380 K, their emission intensity increased by more than 15%. The CINO:0.02Sm 3+ phosphor had a high color purity (98.9%) and reddish-orange chromaticity coordinates (0.608, 0.388). Meanwhile, the manufactured w-LED demonstrated a good color rendering index ( R a = 93), decent CCT (5752 K), and Commission International de l′Eclairage (CIE) chromaticity coordinates (0.327, 0.335). The experimental results demonstrated the superiority of the CINO:Sm 3+ phosphors in 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
Applied Materials Today
·
2025
·
IF 6.9
Wasim Ullah Khan,Waheed Ullah Khan,Haiou Zhu
Thermal quenching and brightness are significant challenges for many phosphors, particularly those used in WLEDs, restricting their effectiveness for large-scale implementation. However, developing phosphors with both anti-thermal quenching (anti-TQ) and high brightness remains quite challenging. Here, we report on the synergistic effect (SE) of energy transfer (ET) offset enabling anti-TQ and intrinsic suppression of concentration quenching (CQ) in sensitized photoluminescent schemes. Anti-TQ (102.1%@400 K) is achieved through the synergistic effect of ET and strong structural rigidity. The chromaticity-shifting (ΔEs) level is 8.63×10 −3 , indicating that it retains PL thermal stability comparable to commercial phosphors. The sensitization effects were investigated both experimentally and through theoretical models as a function of Dy 3+ concentrations. The ET process were studied based on the force electric dipole at each ion, achieving an efficiency of 83.4% and ET rates of 165.8%. The Ca 3 ScAl 3 B 4 O 15 :0.015Tm 3+ ,0.12Dy 3+ -based WLED exhibits satisfactory parameters of R a (83.9) and low-CCT (3345 K). The results highlight how emitters play a crucial role in dissipating excitation energies, offering a new avenue for improving the efficiency of sensitized luminescent materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2020
·
IF 4.825
Zhaowu Wang,Haipeng Ji,Jian Xu,Xinghui Hou,Jumpei Ueda,Setsuhisa Tanabe,Shasha Yi,Ying Zhou,Deliang Chen
A single-crystalline defect-less phosphor is desired for efficient luminescence of the therein doped optical activators. In this paper, microsized MgAl2O4:Mn4+ single-crystal phosphors with bright red luminescence were grown in molten LiCl salt at 950 °C, for application in blue LED pumped white lighting. By comparing the phosphor formation from various Mg2+- and Al3+-bearing sources, both the template-formation and the dissolution-diffusion processes were evidenced to account for the formation of the microsized MgAl2O4:Mn4+ crystallites. Using nano γ-Al2O3 as the Al3+-bearing precursor, the uniform MgAl2O4:Mn4+ microcrystallites with a {111} planes-exposed tetragonal bipyramid morphology were obtained. The photoluminescence property was studied at various temperatures, and Mg ↔ Al anti-site disorder induced luminescence broadening was discussed. The Mn4+2Eg → 4A2g transition in MgAl2O4 shows a quite short luminescence wavelength peaking at 651 nm and ultrabroadband emission extending to 850 nm. The luminescence is relatively robust against thermal effect with relatively high thermal quenching temperature of 400 K and activation energy of 0.23 eV. Employing the red-emitting MgAl2O4:Mn4+ crystallites, blue LED pumped white lighting prototypes were fabricated which simulate the solar-like spectrum and show neutral to warm white.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
LUMINESCENCE
·
2023
·Vol. 38
·期 2
·208-215
·
IF 2.9
Hui Wang,Lingling Wang,Meihua Wu,Minghao Fang,Zhaohui Huang,Xin Min
This paper reports a sequence of a Ca 3 YAl 3 B 4 O 15 :xEu 3+ red phosphor prepared using a high-temperature solid-state reaction. At the excitation of 396 nm, the samples emitted intense red emission centred at ~623 nm, which could be attributed to the 5 D 0 → 7 F 2 transition of the Eu 3+ ion. The results showed that the optimum Eu 3+ doping concentration of Ca 3 YAl 3 B 4 O 15 :Eu 3+ phosphor was x = 80 mol%, and the concentration quenching mechanism of Ca 3 YAl 3 B 4 O 15 :Eu 3+ red phosphor belonged to the exchange coupling between Eu 3+ ions. The Commission Internationale de l'éclairage (CIE) coordinates and colour purity of Ca 3 Y 0.2 Al 3 B 4 O 15 :0.8Eu 3+ were calculated as (0.6375, 0.3476) and 95.5%, respectively. Moreover, the red emission of the obtained phosphor Ca 3 YAl 3 B 4 O 15 :0.8Eu 3+ exhibited a low thermal quenching behaviour with an intensity retention rate of 92.85% at 150°C. The above results manifest that the Eu 3+ -activated Ca 3 YAl 3 B 4 O 15 phosphor is predicted to be a promising red luminescent component for white light-emitting diodes.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Coatings
·
2021
·Vol. 11
·期 5
·581
·
IF 2.881
Linyuan Lian,Youyou Li,Daoli Zhang,Jianbing Zhang
InP quantum dots (QDs) are promising down-conversion phosphors for white light LEDs. However, the mainstream InP QDs synthesis uses expensive phosphorus source. Here, economic, in situ-generated PH3is used to synthesize InP QDs and a two-step coating of ZnS shells is developed to prepare highly luminescent InP/ZnS/ZnS QDs. The QDs show a photoluminescence quantum yield as high as 78.5%. The emission can be tuned by adjusting the halide precursor and yellow emissive InP/ZnS/ZnS QDs are prepared by judiciously controlling the synthetic conditions. The yellow QDs show suppressed thermal quenching and retain >90% room temperature PL intensity at 150 °C for the growth solution. Additionally, the PL spectrum matches with the eye sensitivity function, resulting in efficient InP QD white light LEDs.Keywords:InP;quantum dots;core/shell;InP/ZnS;thermal quenching
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
·
2023
·
IF 3.6
Yufeng Du,Yuxin Li,Yixuan Zhao,Xinyu Zhang,Changlin Li,Ruiqi Yang,Zhequan Zou,Jingjing Lian,Jinyou Duan,Huihong Lin,Ruijin Yu
A new series of red luminescent Cd 2 MgTeO 6 : x Eu 3+ ( x = 0.5–50 mol%) phosphors was successfully synthesized through a high-temperature solid-phase reaction at 1000 °C. The synthesized phosphors were investigated for their phase purity, surface morphology , elemental distribution, and luminescence properties. Strong orange-red light emission (617 nm) was observed upon excitation at 398 nm, which was attributed to the electric dipole 5 D 0 - 7 F 2 transition of Eu 3+ . The optimal doping concentration was found to be x = 20 mol%. Concentration quenching mechanism was identified as the interaction of near-neighbor ions. The chromaticity coordinates of all the Cd 2 MgTeO 6 :Eu 3+ samples were found to be located in the red region and were almost the same. The Cd 2 MgTeO 6 : 20 mol%Eu 3+ phosphors exhibited an unusual thermal quenching behavior, maintaining 102% of the initial intensity, thus possessing excellent thermostability. Moreover, the manufactured white light diode demonstrated a good color rendering index ( R a = 89) with the coordinates of (0.344, 0.330) by the Commission International de L'Eclairage (CIE). Additionally, the Cd 2 MgTeO 6 : 20 mol%Eu 3+ phosphor was surface-functionalized with oleic acid (OA) (Cd 2 MgTeO 6 : 20 mol%Eu 3+ @OA) to aid in the identification of Level I-III fingerprint details with high resolution and contrast. Good visualization of the latent fingerprint (LFP) was observed on different substrates. Therefore, Cd 2 MgTeO 6 :Eu 3+ phosphors hold great promise for the visualization of w-LEDs and LFPs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Liang-Jun Yin,Chao Cai,Hui Wang,Yu-Jie Zhao,Hao Van Bui,Xian Jian,Hui Tang,Xin Wang,Long-Jiang Deng,Xin Xu,Ming-Hsien Lee
Superior thermal quenching and degradation of phosphors are required for long lifetime lighting devices, such as light-emitting diodes, which can be realized through composition modification. Here, Al-N bonds in AlON: Eu 2+ phosphors are substituted by higher bond order of Si-C. Photoluminescence (PL) results show thermal quenching (at 150 °C) and thermal degradation (after 600 °C treatment in air) are improved by 5% and 8% with a small decrease of PL intensity in 5% SiC doped AlON: Eu 2+ phosphor. To explain these observations, first-principles computational study was performed to understand the Si and C configuration in AlON:Eu 2+ . The calculations reveal that Si and C elements are not randomly distributed in AlON lattice. It was found that Si prefers occupying tetrahedral sites (Td-Si) and the insertion of C in Td-Si is always energetically favorable, which results in the formation of SiC 4 and SiNC 3 clusters. Thus, the Al-N substitution by Si-C induces a stronger local structure, which accounts for the emission redshift and better thermal stability.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2015
·
IF 2.288
Xiang-Yang Chen,Zhi-Jun Zhang,Ang Feng,Meng Xu,Jing-Tai Zhao,Fang-Fang Xu
Density functional theory calculations on monoclinic Lu 2 WO 6 is carried out using the Cambridge Sequential Total Energy Package code. The result indicates that Lu 2 WO 6 is a broad band gap semiconductor with an indirect band gap of 3.13 eV. Eu ions are trivalency and the average coordination number is 7.6(5), indicating that the site of Lu is occupied by Eu. The activation energy Δ E is calculated as 0.314 eV. In addiation, the thermal quenching mechnism of Eu-activated Lu 2 WO 6 and the different concentration quenching mechanisms for 5 D 0 and 5 D 1 emissions of Eu ions have been proposed.
研究领域:
材料科学
·
物理学
✓ 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）