JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Bing Zhang,Yixin Luo,Binqiong Peng,Lisha Zhang,Ning Xie,Dan Yue,Weidong Li,Bowen Qin,Wenjing Du,Zhenling Wang,Yilei Zhang
The paper presents a green and easily prepared water-soluble fluorescent nitrogen doped carbon dots (N CDs) synthesized by one-step hydrothermal process. The N CDs displays brilliant blue fluorescence excited by UV light, with excellent water solubility, and a quantum yield of 15.7 %. The fluorescence intensity of N CDs remains unchanged after 48 h of exposure to ultraviolet light, exhibiting good photostability. Moreover, the ion sensing characteristics of these N CDs have been explored for more than a dozen anions and cations. The result reflects that this fluorescent CDs exhibits excellent sensitivity and selectivity for Fe 3+ within a range spanning of 40 ∼ 500 μΜ with a limit of detection down to 0.22 μΜ. The principle of sensor sensing is likely related to the formation of the internal filtering effect (IFE), which leads to a decline in the fluorescence intensity of N CDs in aqueous solutions containing Fe 3+ . Due to the excellent water solubility, good photostability and high yield of N CDs, the application of prepared N CDs/polyvinyl alcohol (PVA) as fluorescent materials for white LED devices was explored. The prepared N CDs/PVA (NCP) composite film can also exhibit bright blue light under 365 nm excitation, indicating good application prospects in the area of white LED devices and agricultural films.
研究领域:
材料科学
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光学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Xiaoyi Liu,Haiming Cheng,Bin Yue,Zhu Wen,Ying Jin,Guixia Liu,Shengda Liu,Dan Li,Jinxian Wang,Wensheng Yu,Xiangting Dong
Novel eye-sensitive Ba 3 Nb 2 O 2 F 12 (H 2 O) 2 :Tb 3+ green and Ba 3 Nb 2 O 2 F 12 (H 2 O) 2 :Mn 4+ red oxyfluoride phosphors with extremely strong absorption in the UV region were designed and synthesized by simple co-precipitation strategy. Particularly, Tb 3+ ions were doped in this matrix for the first time, which greatly improves their absorption efficiency in the near ultraviolet region (367 nm) and emits sharp green light (544 nm). In addition, the Ba 3 Nb 2 O 2 F 12 (H 2 O) 2 :Mn 4+ red phosphors have strong zero phonon line (ZPL) emission at 625 nm, which is conducive to improving the sensitivity of human eye and color purity. Meanwhile, the optical properties of the red phosphor are significantly enhanced via doping K + cations as charge compensators. Crystal field environment and nephelauxetic effect of the as-prepared phosphors before and after K + cation doping were systematically analyzed. Moreover, these synthesized red/green phosphors have good thermal stability and moisture resistance. Remarkably, the as-prepared Ba 3 Nb 2 O 2 F 12 (H 2 O) 2 :5%Mn 4+ or K 0.9 Ba 2.1 Nb 2 O 2 F 12 (H 2 O) 2 :5%Mn 4+ red phosphors can be directly mixed with the as-synthesized Ba 3 Nb 2 O 2 F 12 (H 2 O) 2 :13%Tb 3+ green phosphor coating on 365 nm near-ultraviolet LED chip to package WLED devices with excellent electroluminescence performance. These findings are conducive to opening an avenue for screening the unique structure of optical materials.
研究领域:
材料科学
·
光学
✓ 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
Advanced Optical Materials
·
2024
·
IF 8
Moushira. A. Mohamed,Mohamed. A. Ali,Guo Shaorun,Xiaofeng Liu,Jianrong Qiu
Phosphor-in-silica glass (PiSG) composite is an excellent candidate for highly stable and efficient color converter in high power white light emitting diodes (wLEDs). However, the high-throughput fabrication of PiSG with different shapes is still challenging for current techniques. Here this study reports the manufacture of transparent PiSG based on YAG:Ce (Y 3 Al 5 O 12 :Ce 3+ ) using injection molding (IM) technique. In this approach, different shapes of centimeter-sized YAG:Ce-PiSG pieces are fabricated by using IM of a YAG:Ce/amorphous silica nanoparticles/thermoplastic polymer composite at low temperatures (@ 150 °C) which afterward are debound (@ 600 °C) and densified (@ 1150 °C). Interestingly, the molding time to produce YAG:Ce/silica/polymer green parts is 5 s per piece, implying the capability for high-throughput production of YAG:Ce-PiSG. Furthermore, the as-fabricated YAG:Ce-PiSG exhibits high luminescence efficiency (>91%) and high chemical/thermal stabilities. Accordingly, high power wLEDs (10 W) are fabricated using the YAG:Ce-PiSG which demonstrates high luminous efficiency of 144 lm W −1 at 50 mA, closing to that of the wLEDs fabricated by expensive YAG:Ce ceramic plate (i.e., 149 lm W −1 @ 50 mA). The work provides a facile and universal approach for industry-scale production of PiSG that can be promising for various photonic 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 MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 23
·1-10
·
IF 2.8
Ni Wei,Zhang Chuancheng,Liu Hailian,Wang Miaomiao,Zou Yong,Liu Wenpeng,Ding Shoujun
The development of narrowband green phosphors with high efficiency and stability plays an important role in the designing of high-performance backlight white light-emitting diode (WLED) devices. In this work, trivalent terbium host-sensitized orthoniobate green phosphor, TbNbO 4 , has been prepared using the traditional high-temperature solid-state reaction method. The phosphor has a monoclinic structure with the space group C2/c. Besides, the TbNbO 4 is revealed with a direct bandgap structure and the bandgap is determined to be 3.67 eV by first principle calculation. Under 353 nm UV excitation, TbNbO 4 phosphor shows strong and narrow-band green emission with center around 550 nm, attributed to the 5 D 4 → 7 F 5 transition of Tb 3+ ions. Furthermore, the results demonstrated that the phosphor exhibits favorable thermal stability and activation energy, with a notably high activation energy value of 0.24 eV. This observation suggests that the host-sensitized TbNbO 4 phosphor holds potential as narrow-band green-emitting alternative for backlighting white light-emitting diodes (WLED) display application.
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
DALTON TRANSACTIONS
·
2024
·Vol. 53
·期 9
·4325-4341
·
IF 3.5
P. J. Xia,X. Z. Zheng,L. Yue,Y. F. Lei,M. Xu,W. B. Dai
For further development of light sources, white light-emitting diodes (wLEDs) have attracted widespread attention as promising next-generation light sources fabricated via the combination of phosphors and LED chips. However, latent defects, such as chemical/thermal instability, low color rendering index (CRI) and high correlated color temperature (CCT), of current mainstream wLEDs seriously hinder their further large-scale implementation. Herein, in order to overcome these limitations, single-phase color-tunable gaudefroyite (Ca3Y(GaO)3(BO3)4 (CYGB)) tridoped with Bi3+/Tb3+/Eu3+ ions was synthesized for the first time and detailed characterisation was performed via high-temperature solid-state reaction and structural/spectral analyses, respectively. Radius difference percentage calculations and Rietveld refinements indicate that dopants occupy both Y3+ and Ca2+ sites but preferably the Y3+ site over the Ca2+ site due to the same valence state. Through subtly regulating the (co)doping contents and skillfully utilizing the energy transfer (ET) strategy from the allowed transition of blue light-emitting Bi to the forbidden transition of green/red light-emitting Tb/Eu, the color hue (including white light) of highly efficient PL can be easily tuned according to the need. Meanwhile, composition/content-optimized white light-emitting CYGB:2%Bi/10%Tb/12%Eu also shows splendid chemical/thermal stability. Finally, as a proof-of-concept experiment, the CYGB:2%Bi/10%Tb/12%Eu phosphor-converted wLED (pc-wLED) was fabricated and encapsulated via the up-to-date remote ‘capping’ method, which imparted attractive performances. Altogether, the stable CYGB:Bi/Tb/Eu phosphor is a promising candidate for application in lighting/display fields.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Jiazhuang Guo,Pan Zhang,Liangliang Zhu,Hao Chen,Hai-Xia Shen,Cai-Feng Wang,Su Chen
Multicolor emissive carbon dots (CDs) have received increasing attention due to their excellent optical features. By far, insufficient studies have been conducted on the preparation and modulation of multicolor CDs, and most of the precursors used for the synthesis of multicolor CDs own benzene rings. Here, we report the solvent-engineered preparation of CDs with bright multicolor emissions. The CDs are fabricated by hydrothermal/solvothermal treatment of citric acid and cyanamide, circumventing the use of precursors containing aromatic molecules as well as the medium of concentrated acids. By simply changing the reaction solvent, the emission wavelength of the CDs shifts from the blue to yellow region, and even white emissive CDs are obtained. Specifically, blue, cyan, yellow, and white emissive CDs are obtained to exhibit photoluminescence quantum yields (PL QYs) ranging from 19.7% to 62.3%. Further studies show that the bright fluorescence might originate from molecular fluorophore grafting on the CD surface. Moreover, CDs/polymer composites with uniform bright luminescence are prepared and used as fluorescent color-converting materials for fabricating multicolor LEDs. This study extends the modulated preparation of multicolor emissive CDs that are potentially useful for optoelectronic applications.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2025
·
IF 5.5
Yanqing Zu,Tong Zhang,Binglin Zeng,Decui Gong,Chengzhang Yang,Chujie Wang,Run Gan,Lixia Jing,Peitao Liu,Xiaodong Li,Lei Zhao,Ailing Feng,Zhaoxin Wu
Perovskite nanocrystals (NCs) have attracted much attention in the fields of laser, color conversion and X-ray imaging. However, the poor photophysical properties and stability of NCs due to the proton exchange of traditional X-type ligands such as the pair of oleic acid and oleylamine as well as their easy detachment after purification or long-time storage, have become the major bottleneck for practical applications. Herein, we exploit an in-situ passivation strategy for CsPbBr 3 NCs by merely using a L-type bidentate ligand, namely 1,3-bis(3-aminopropyl) tetramethyldisiloxane (BAPTRDS). Theoretical calculations indicate that this double bridging of BAPTRDS on the surface of NCs can achieve a much larger binding energy (−1.86 eV) in comparision to single chelated 3-aminopropyl-triethoxysilane (APTES) (−1.05 eV). The BAPTRDS passivated NCs exhibit a high photoluminescence quantum yield of 71 %. Besides, the X-ray imaging detector and white light-emitting diodes (WLEDs) were separately obtained by BAPTRDS capped NCs, both of which possess the impressive performance. This work not only can provide deep understanding for surface chemistry of perovskite NCs, but also acquire high-quality CsPbBr 3 NCs for dual applications in X-ray imaging and display.
研究领域:
材料科学
·
光学工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
You Zhang,Kun Zhao,Haoyu Zhu,Qiong Xi,Nian Fu,Dawei Wang,Jinxing Zhao,Li Guan,Yunfei Zhuang,Xu Li
White light-emitting diodes (WLEDs) have emerged as a leading technology for healthy lighting and advanced displays. Nevertheless, the poor thermal stability of blue-emitting components remains a significant bottleneck, hindering their broader adoption in demanding environments. Here, we have prepared a series of Ca 3 Al 2 O 6 :Ce 3+ phosphors by high temperature solid-state method. Substituting the [Al 3+ –O 2- ] ionic pair with [Si 4+ –N 3- ] in the Ca 3 Al 2 O 6 host lattice via a charge-compensated strategy achieves a 1.75 times enhancement in thermal stability compared to the pristine material, while simultaneously inducing a blue-shifted emission spectrum (Δλ = 30 nm). The enhanced thermal stability originates from increased lattice rigidity, while the blue spectral shift arises from modulated crystal field splitting decrease. These mechanistic insights provide a foundational strategy for designing ultra-stable blue phosphors compatible with high-power WLED 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
Materials
·
2025
·Vol. 18
·期 9
·1896
·
IF 3.2
Yanbiao Li,Yuefeng Gao
Stable and efficient inorganic lead-free double perovskites are crucial for high-reliability optoelectronic devices. However, dual-doped perovskite phosphors often suffer from poor color stability due to differences in thermal activation energies and electron–phonon interactions between the doped ions. To address this, single-doped Sb3+-incorporated Rb2HfCl6perovskite crystals were synthesized via a co-precipitation method. Under UV excitation, Rb2HfCl6:Sb exhibits broad dual emission bands, attributed to singlet and triplet self-trapped exciton radiative transitions induced by Jahn–Teller distortion in [SbCl6]3−octahedra. This dual emission endows the material with high sensitivity to excitation wavelengths, enabling tunable luminescence from cyan to orange-red across 400–800 nm. Utilizing this dual emission, a white LED was fabricated, showcasing a high color rendering index and excellent long-term stability. Remarkably, the material exhibits breakthrough thermal stability, maintaining more than 90% of its emission intensity at 100 °C, while also exhibiting remarkable resistance to humidity and oxygen exposure. Compared to co-doped phosphors, Rb2HfCl6:Sb offers advantages such as environmental friendliness, simple fabrication, and stable performance, making it an ideal candidate for WLEDs. This study demonstrates notable progress in developing thermally stable and reliable optoelectronic devices.
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
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Shaokun Ling,Yaxiong Wang,Xiaoyan Qin,Chang Chen,Chunchun Lu,Jidong Chen,Sen Liao,Yingheng Huang,Lei Hou
Although being applied in various fields, white light emitting diodes (WLEDs) still have drawbacks that urgently need to be conquered: the luminescent intensity of commercial phosphors sharply decreases at working temperature. In this study, we calculated the forming energy of defects and confirmed that the VNa defect state can stably exist in β-NaGdF4, by density functional theory (DFT) calculation. Furthermore, we predicted that the VNa vacancies would provide a zero thermal quenching (ZTQ) property for the β-NaGdF4-based red-light phosphor. Then, a series of β-NaGdF4:xEu3+ and β-NaGdF4:0.25Eu3+,yYb3+ red-light phosphors were synthesized by the hydrothermal method. We found that β-NaGdF4:0.25Eu3+ and β-NaGdF4:0.25Eu3+,0.005Yb3+ phosphors possess ZTQ properties at a temperature range between 303–483 K and 303–523 K, respectively. The thermoluminescence (TL) spectra were employed to calculate the depth and density of the VNa vacancies in β-NaGdF4:0.25Eu3+ and β-NaGdF4:0.25Eu3+,0.005Yb3+. Combining the DFT calculation with characterization results of TL spectra, it is concluded that electrons stored in VNa vacancies are excited to the exited state of Eu3+ to compensate for the loss of Eu3+ luminescent intensity. This will lead to an increase of luminescent intensity at high temperatures and facilitate the samples to improve ZTQ properties. WLEDs were obtained with CRI = 83.0, 81.6 and CCT = 5393, 5149 K, respectively, when phosphors of β-NaGdF4:0.25Eu3+ and β-NaGdF4:0.25Eu3+,0.005Yb3+ were utilized as the red-light source. These results indicate that these two phosphors may become reliable red-light sources with high antithermal quenching properties for WLEDs.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2017
·Vol. 46
·期 40
·13835-13844
·
IF 4.029
Luqing Xi,Yuexiao Pan,Mengmeng Zhu,Hongzhou Lian,Jun Lin
A novel red phosphor, NaHF2:Mn4+ (NHF:Mn), was obtained via substituting Na+ located at the center of the octahedron coordinated with six F− ions with Mn4+ in the host lattice of NHF. The phase purity and the exact composition of the obtained NHF:Mn were confirmed by X-ray powder diffraction (XRD), Rietveld refinement, energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and infrared (IR) spectroscopy, respectively. The luminescence intensity of NHF:Mn was enhanced by optimizing the synthetic conditions. A series of warm white light-emitting diodes (WLEDs) with a color rendering index (CRI) higher than 88.0 and correlated color temperatures (CCT) between 3146 and 5172 K were obtained by encapsulating the as-prepared red phosphor NHF:Mn with the yellow one Y3Al5O12:Ce3+ (YAG:Ce) on blue chips. The advantage of the synthetic strategy to obtain NHF:Mn can be extended to develop novel Mn4+ doped red phosphors via substituting for central ions with unequal electric charge in the centers of octahedra.
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
危险品化学品经营许可证（带存储）