JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2021
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IF 4.291
Wei Li,Liangling Sun,Balaji Devakumar,Nan Ma,Zongjie Zhang,Xiaoyong Huang
In this work, we demonstrated novel Mn 4+ -activated double-perovskite SrLaZnSbO 6 (SLZS) far-red-emitting phosphors for plant cultivation LED lighting. These SLZS:Mn 4+ far-red-emitting phosphors doped with various Mn 4+ concentrations were successfully prepared by using a traditional high-temperature solid-state reaction route. The phase purity, crystal structure, photoluminescence properties, decay lifetimes, CIE chromaticity coordinates and temperature-dependent spectra of as-prepared samples were systematically studied. The SLZS:Mn 4+ phosphors showed an intense far-red emission band in the 650−800 nm spectral region with a maximum at 706 nm under 364 nm excitation, which was due to the 2 E g → 4 A 2g transition of Mn 4+ ions. The optimal doping concentration of Mn 4+ ions in SLZS:Mn 4+ phosphors was found to be 0.5 mol%. And the CIE chromaticity coordinates of SLZS:0.5 %Mn 4+ phosphors were calculated to be (0.7276, 0.2724), which were located in the far-red region. The emission spectrum of SLZS:Mn 4+ phosphors could match well with the absorption band of phytochrome P FR . All of these results demonstrate that SLZS:Mn 4+ phosphors have a huge potential application in indoor plant cultivation.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2020
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IF 7.489
Gongxi Qiao,Gui Chen,Qin Wen,Wanqiang Liu,Jinwei Gao,Zhiqiang Yu,Qianming Wang
The commercial production of carbon dots will be concerned with the simplicity and energy consumption. Herein, maleic acid and m-phenylenediamine form elegantly simple sources for carbon dots. The two precursors are dissolved in formamid (abbreviated as FA) or N, N -dimethylformamide (abbreviated as DMF) and the dehydration-condensation processes have been performed at 30 min or 120 min under room temperature. No external energy/irradiations, reactants or high temperature will be required and the afforded carbon dots (abbreviated as CDs) are collected by extraction, centrifugation, dialysis and column chromatography. It has been found for the first time the choice of organic solvents has been correlated with emission color. The blue-emitting CDs (abbreviated as B-CDs) and green-emitting CDs (abbreviated as G-CDs) are yielded in FA and DMF respectively. Facts support that the increase of –CONH- units causes red-shift in emissions. The optical sensing of tetracycline has been explored and the detection limit of blue-emitting CDs is as low as 25 nM. Live cells exposed to B-CDs and G-CDs (0.5 mg/ml) show no apparent changes via both Cell Counting Kit-8 and Annexin V/7-AAD analysis. The blue and green fluorescent signals can be easily tracked in cells. It has been demonstrated that the two carbon dots can be fabricated as multiple-color light-emitting diodes (abbreviated as LEDs).
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高影响因子
JOURNAL OF LUMINESCENCE
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2020
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IF 3.28
Xiaoyong Huang,Shaoying Wang,Jia Liang,Balaji Devakumar
In this work, novel Eu 3+ ions activated red emitting Ca 2 YTaO 6 (CYT) phosphors have been prepared via a high-temperature solid-state reaction approach. Their crystal structure and photoluminescence properties were investigated by X-ray diffraction (XRD) patterns, photoluminescence excitation and emission spectra , and decay lifetimes. XRD Rietveld refinement results revealed that the CYT:Eu 3+ phosphors crystallized in the monoclinic structure with the space group of P 2 1 / n and lattice parameters of a = 5.5989 Å, b = 5.8449 Å, c = 8.1016 Å, α = γ = 90°, β = 89.8799°, and V = 264.625 Å 3 . The CYT: x Eu 3+ phosphors could be excited by near-ultraviolet light around 396 nm, and they showed bright narrowband red emissions peaking at 590, 614, 656, and 703 nm due to the 5 D 0 → 7 F J (J = 1–4) transitions of Eu 3+ ions. The 614 nm red emission corresponding to the 5 D 0 → 7 F 2 transition was dominant in the emission spectra, indicating that the Eu 3+ ions occupied non-centrosymmetric sites. The critical quenching concentration in CYT: x Eu 3+ phosphors was 50 mol%, and the optimal CYT:0.5Eu 3+ phosphors showed PL intensity as great as 4.2 times higher than the commercial red phosphors Y 2 O 3 :Eu 3+ . CIE chromaticity coordinates of CYT:0.5Eu 3+ phosphors were (0.6678, 0.3319), and the color purity reached up to 97.4%. The nonradiative energy transfer between the Eu 3+ ions in the CYT host was attributable to dipole-dipole interaction, and the critical distance was roughly 7.97 Å. A warm white light-emitting diode (w-LED) based on the combination of a 395 nm LED chip with a blend of commercial BaMgAl 10 O 17 :Eu 2+ blue phosphors and commercial (Ba,Sr) 2 SiO 4 :Eu 2+ green phosphors and as-prepared CYT:0.5Eu 3+ red phosphors was fabricated, which gave warm white-light emission with excellent CIE color coordinates of (0.3833, 0.3859), low correlated color temperature of 3991 K, high color rendering index of 92.1, and good luminous efficacy of 21.76 lm/W.
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JOURNAL OF LUMINESCENCE
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2019
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IF 2.961
Hai Guo,Zhigang Zheng,Liming Teng,Rongfei Wei,Fangfang Hu
In this paper, a series of Bi 3+ and Eu 3+ single-doped as well as Bi 3+ ,Eu 3+ co-doped Ba 9 Y 2 Si 6 O 24 samples were synthesized through a simple high-temperature solid-state reaction method. Their crystal structures, morphologies, luminescent properties, temperature-dependent emission spectra , decay curves and quantum efficiencies were investigated in detail. Upon ultraviolet light excitation, Bi 3+ single-doped samples exhibited blue and green emissions peaking at 408 and 501 nm, corresponding to the 3 P 1 – 1 S 0 transition of Bi 3+ ions. The spectral analysis indicated that there were two different luminescent centers of Bi 3+ ions due to different occupancies in Ba 9 Y 2 Si 6 O 24 host lattice. And the highest quantum efficiency can reach 64.5% in Ba 9 Y 2 Si 6 O 24 :0.024Bi 3+ phosphor. The remarkable spectral overlap between the emission spectra of Bi 3+ ions and the excitation spectra of Eu 3+ ions indicated the exist of energy transfer from Bi 3+ to Eu 3+ . The efficient energy transfer from Bi 3+ to Eu 3+ has been investigated in detail and resulted in that tunable and white-light emission can be obtained by modulating Eu 3+ doping concentration. White emission can be realized with the CIE coordinates of (0.357, 0.345) and quantum efficiency of 57.6% for Ba 9 Y 2 Si 6 O 24 :0.024Bi 3+ ,0.02Eu 3+ . The above results demonstrate that Ba 9 Y 2 Si 6 O 24 :Bi 3+ ,Eu 3+ may be a potential candidate for ultraviolet (UV) driven white light-emitting diodes (w-LEDs).
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高影响因子
OPTICAL MATERIALS
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2017
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IF 2.238
Chaoyang Ma,Yongge Cao,Xiaofei Shen,Zicheng Wen,Ran Ma,Jiaqi Long,Xuanyi Yuan
Nowadays, major commercial w-LEDs fabricated by the traditionally gold-wire-welding packaging technology have undergone considerable development as indoor/outdoor lighting sources due to its high-energy utilization efficiency, long service life, environmental friendliness, and excellent chromatic stability. While, new generation applications in projections, automotive lighting, street lighting, plaza lighting, and high-end general lighting need further improvements in power handling and light extraction. Herein, transparent Ce:YAG glass-ceramics (GCs) phosphor was prepared by low-temperature co-sintering polycrystalline Ce:YAG phosphor powder and home-made PbO-B 2 O 3 -ZnO-SiO 2 glass powder. Thereafter, the flip-chip (FC) w-LEDs were fabricated with the GCs phosphor plates and FC blue chips. The GCs-based FC w-LEDs show not only excellent heat- and humidity-resistance characteristics, but also superior optical performances with an LE of 112.8 lm/W, a CRI of 71.2, a CCT of 6103 K as well as a chromaticity coordinate of (0.3202, 0.3298), under a high operation current of 400 mA. The technology route will open a practically commercial feasible approach to achieve excellent performances for advanced high-power FC w-LEDs.
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高影响因子
INORGANIC CHEMISTRY
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2025
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IF 4.7
Yichen Zhu,Yubin Kang,Jing Su,Zhi Wen,Mingchun Li,Qiangqiang Zhu,Yue Zhai,Juan Kang,Yanghui Li,Le Wang
Lead halide perovskites have garnered interest in light-emitting diode (LED) applications due to their strong emission and tunable properties. However, conventional synthesis methods involve energy-intensive thermal processes and hazardous organic solvents, raising environmental concerns. In this study, we report a simple and eco-friendly mechanochemical approach that produces phase-pure blue-emitting Cs3Cu2I5 (emission at 440 nm) and yellow-emitting CsCu2I3 (emission at 570 nm) phosphors through polarity modulation and control of grinding duration. Our comprehensive analysis of the phase transitions during mechanochemical synthesis reveals that pure Cs3Cu2I5 was synthesized from a 3:2 precursor molar ratio in ethanol for 30 min, while pure CsCu2I3 was obtained from a 1:2 precursor molar ratio in an aqueous solution for 7.5 min. Moreover, Raman spectroscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy analyses confirmed that phase-pure phosphors were achieved through these methods. Finally, we fabricated a series of color-adjustable LEDs by mixing Cs3Cu2I5 and CsCu2I3 phosphors in different proportions. This demonstrates the potential of our mechanochemical synthesis for the efficient, large-scale production of next-generation lighting materials with tunable emission.
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高影响因子
INORGANIC CHEMISTRY
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2024
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IF 4.3
Yiying Zhu,Guoxun Sun,Yining Wang,Yixin Sun,Xiaole Xing,Mengmeng Shang
Doping lanthanide ions is an efficient method to modify the optical properties of lead-free double-perovskite halides. However, most lanthanide-doped double perovskites show a low luminescence efficiency and require a high excitation energy. Here, we have successfully prepared a series of Ho3+-doped Cs2NaBiCl6 microcrystals through a simple hydrothermal method and obtained strong characteristic emissions of Ho3+ at 492 and 657 nm under low-energy excitation (449 nm). After codoping Mn2+, apart from the characteristic emissions from Ho3+ under 450 nm wavelength excitation, the orangish-red luminescence consisting of the emission band centered at 591 nm from Mn2+ and a sharp emission peak at 657 nm from Ho3+ is obtained under 355 nm UV light excitation. Photoluminescence (PL) emission and excitation spectra, along with the PL decay curves, confirm the existence of an energy-transfer channel from Cs2NaBiCl6 to Mn2+ and then from Mn2+ to Ho3+. The enhanced absorption efficiency (10.5 → 70.7%) suggests that the codoping of Mn2+ overcomes the low absorption efficiency caused by f–f forbidden transitions of Ho3+. Finally, the diverse luminescent performance within the Cs2NaBiCl6:Ho3+, Mn2+ phosphor is realized by altering the excitation wavelength, thereby enabling its application in warm-white-light-emitting diodes and plant growth in this work.
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高影响因子
CERAMICS INTERNATIONAL
·
2024
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IF 5.1
Shengqian Wang,Junqiang Gu,Jinying Liu,Feiyan Xie,Chaochao Tao,Shuo Wang,Hualan Xu,Shengliang Zhong
Phosphors with high luminescence efficiency, tunable emission and high color rendering index (CRI) are vital importance for the quality of white light emitting diodes (w-LEDs) in real application. In this work, a new single phase color-tunable Na 5 Lu(WO 4 ) 4 :Tb 3+ ,Eu 3+ phosphor with outstanding luminescent properties was designed and synthesized. Its crystal structure, electronic structure, and luminescence features were studied in detail. The band gap of the host was calculated to be about 4.68 eV. The differential charge distribution after Tb, Eu doping through density functional theory simulation theoretically proved the electron redistribution in the W-O bond upon substitution of Tb 3+ /Eu 3+ . The energy transfer of Tb 3+ →Eu 3+ enabled tunable emission of luminescent colors from green to orange-red due to the quadrupole-quadrupole interaction. The optimal Na 5 Lu(WO 4 ) 4 :60%Tb 3+ ,20%Eu 3+ phosphor exhibited excellent photoluminescence quantum yield of 84.19 % and good luminescent thermal stability (I 423K/298K = 75.90%) with an activation energy of 0.1976 eV. Finally, a white LED device with color coordinates of (0.3371, 0.3636), color rendering index of 89.4 and correlated color temperature of 5334 K was fabricated. These findings demonstrated that Na 5 Lu(WO 4 ) 4 :60%Tb 3+ ,20%Eu 3+ phosphor could be a potential orange-red-emitting color converter for white LEDs. This work not only assisted in the understanding of experimental observations but also provided a theoretical basis for the rational design of phosphors.
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Materials Today Chemistry
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2024
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IF 6.7
Jingming Chan,Balaji Devakumar,Huanzhuo Gao,Xiaoyong Huang
High-color-rendering full-spectrum warm-white light-emitting diodes (LEDs) are in great demand in the field of high-end solid-state white lighting. However, the so-called cyan gap (480–520 nm) in conventional white LEDs always limits their color rendering index (CRI) values, and thus there is a pressing need for cyan phosphors to fabricate full-spectrum white LEDs. Herein, we report on an efficient violet-excited blue-cyan-emitting Ca 2 YHf 2 GaAl 2 O 12 :Ce 3+ (CYHGA:Ce 3+ ) garnet phosphor, which is capable of realizing full-spectrum warm-white LEDs with superior CRI (Ra = 98.2, R12 = 96, R9 = 95) and low correlated color temperature (CCT) of 3735 K. Importantly, when excited at 398 nm, the optimal CYHGA:2%Ce 3+ sample exhibits a strong broadband blue-cyan emission (emission peak: 473 nm; emission bandwidth: 92 nm) with high luminescence efficiency (internal quantum efficiency: 69.9 %; external quantum efficiency: 43.3 %), which perfectly covers both blue and cyan spectral region and enables to close the so-called cyan gap. The fabricated warm-white LED device based on CYHGA:2%Ce 3+ blue-cyan phosphor generates bright warm-white lights with ultra-high CRI values (Ra ≥96.5; R12 ≥ 94; R9 ≥ 93) and low CCT values (3674–3845 K) upon 20–320 mA driving currents. Thus, blue-cyan-emitting CYHGA:Ce 3+ garnet phosphors possess a bright application prospect in high-quality full-spectrum LED lighting.
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高影响因子
CERAMICS INTERNATIONAL
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2025
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IF 5.6
Zhiwei Xia,Yuhan Wang,Rujun Yang,Mengdi Xu,Cunjian Lin,Zhongyuan Li,Ying Lv,Xiaopeng Chi,Shihai You
The interstitial site engineering that purposely creates interstitial luminescent centers in suitable hosts has become an intriguing strategy in designing novel inorganic phosphors. However, effectively tuning the photoluminescence of interstitial activators remains tough challenging at this stage. Here, we demonstrate the effective modulation of interstitial luminescence in inorganic phosphor. In detail, the blue emission band ( λ em = 446 nm) of interstitial Eu 2+ doped α -cristobalite (SiO 2 :Eu 2+ ) is largely enhanced and broadened via a partial, aliovalent substitution of Si 4+ by Al 3+ . After introducing Al 3+ ions into SiO 2 lattice, the full width at half maximum of the blue emission band increase from 59 to 76 nm with a triple growth in quantum efficiency (10.82% → 35.56%). Moreover, the thermal stability improves significantly with a high emission retention of 60% at 325 °C (SiO 2 :0.06Al 3+ ,0.005Eu 2+ ), far higher than that of the parent SiO 2 :0.005Eu 2+ (30%). Encapsulating blue-emitting SiO 2 :Al 3+ ,Eu 2+ along with two commercial green and red phosphors on an ultraviolet LED chip ( λ em = 375 nm), a white LED device with high color rendering index (Ra > 90) was successful fabricated, showing the great potential of this phosphor for achieving high-quality white LED lighting. This study not only provides a promising bule emitter but also sheds light on modulating interstitial luminescence properties in inorganic phosphors.
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高影响因子
ACS Applied Electronic Materials
·
2025
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IF 4.7
Zhixian Wu,Xueyong Zheng,Chunli Jiang,Junhan Xie,Weimin Liu,Bo Li,Hechun Lin,Hui Peng,Chunhua Luo
Tin (Sn)-based perovskite light-emitting diodes (PeLEDs) have garnered significant attention owing to their superior optoelectronic properties, affordable solution processing, and environmental friendliness. However, the properties of Sn-PeLEDs trail those of their lead (Pb) counterparts. The main obstacle is the easy oxidation of Sn2+ to Sn4+ as well as fast crystallization, leading to poor film quality with many defects. Herein, a convenient and effective interface engineering strategy is reported to fabricate (2-thiopheneethylamine)2SnI4 (TEA2SnI4) PeLEDs by introducing different peptides into the PEDOT:PSS hole-transport layer (HTL). Benefiting from the interaction between the peptide molecules and the Sn-perovskite nuclei, the crystallization dynamics are effectively adjusted, leading to an improved film morphology. At the same time, the multiple functional groups of peptides can suppress Sn2+ oxidation and passivate interface defects. Therefore, perovskite films with improved luminescence efficiency are obtained. The perovskite films are further used for the fabrication of pure red PeLEDs with enhanced performance. In particular, the optimized devices based on Leu-Gly-Gly (LGG) achieve a peak external quantum efficiency of 0.5% and a brightness of 136 cd m–2, which are about 2 and 3 times larger, respectively, than those of the reference device. This research offers a general strategy to improve the performance of Sn-PeLEDs via peptide interface engineering.
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高影响因子
OPTICAL MATERIALS
·
2025
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IF 4.2
Rouziaji Alimu,Reziwanguli Yantake,He Jiuyang,Wang Qingling,Aierken Sidike
To achieve high-color-rendering WLED devices, exploration of blue‒cyan phosphors that can be excited by near-ultraviolet (NUV) chips is particularly important to compensate for the cyan gap. In this work, feldspar-structured Sr 1-y Al 2- x Ga x Si 2 O 8 :yCe 3+ blue-cyan phosphors were prepared via a high-temperature solid-phase method and a cation substitution strategy. The luminescence performance of the Sr 0.96 Al 2 Si 2 O 8 :0.04Ce 3+ sample was improved by applying the cation substitution strategy of partially replacing Al 3+ with Ga 3+ , and the representative sample Sr 0.96 Al 1.4 Ga 0.6 Si 2 O 8 :0.04Ce 3+ was obtained. The luminescence intensity increased threefold for the Sr 0.96 Al 1.4 Ga 0.6 Si 2 O 8 :0.04Ce 3+ compound compared to Sr 0.96 Al 2 Si 2 O 8 :0.04Ce 3+ , and a broadband blue‒cyan phosphor with a half-height width of 100 nm was obtained. The representative sample Sr 0.96 Al 1.4 Ga 0.6 Si 2 O 8 :0.04Ce 3+ showed relatively good thermal stability. Sr 0.96 Al 1.4 Ga 0.6 Si 2 O 8 :0.04Ce 3+ was combined with 365 nm NUV LED chips and commercial (Sr, Ca)AlSiN 3 :Eu 2+ to obtain WLED devices with color rendering index (Ra) as high as 94.8 and correlated color temperatures (CCTs) as high as 4831.4 K. These results show that the blue-cyan phosphor complements the cyan component while simplifying the manufacturing process of WLEDs.
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高影响因子
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