Applied Materials Today
·
2019
·
IF 8.013
Quan Xu,Wenjing Yang,Yangyang Wen,Shengkun Liu,Zheng Liu,Wee-Jun Ong,Neng Li
Multiple-color emissive MXene quantum dots (MQDs) exhibit vast application prospects in various fields, including optoelectronics, bioimaging, and catalysis. However, the majority of the recent MQDs display limited maximum emission in the blue-light region. Herein, we employ the hydrogen bonds as an adjustment method to prepare novel full-color MQDs using Ti 3 C 2 MXene as the starting material. By doping with sodium thiosulfate and ammonia water (sulfur-doped, nitrogen-doped), the maximum emission of the obtained MQDs demonstrates entire light spectrum covering from blue to orange light. Interestingly, the as-synthesized Ti 3 C 2 MQDs aqueous solutions unveil multiple-color, excitation-independent emission wavelength and fluorescence (lifetime and quantum yield) enhancement compared with in the dry state. The fluorescence shift and enhancement are confirmed by comprehensive spectroscopic techniques (e.g. grazing incidence X-ray diffraction (GIXRD)) and complementary density functional theory (DFT) calculations. The results indicate that the construction of stalwart bridge-like hydrogen-bonded networks between the MQDs by highly ordered bound water on the doped MQDs surface can give rise to the immobilization of the C O and C–O bonds of the MQDs, thus strengthening the rigidity of the entire system. As a benefit of the bandgap emission, white light-emitting diodes (WLEDs) with stable emission color by directly utilizing MQDs as an active emission layer have been realized for the first time. As such, the as-prepared full-color MQDs developed herein can remarkably broaden the prospect of MXene 2D quantum dots (2D-QDs) in a myriad of technological applications such as electronics, batteries, bioimaging, and cancer therapy.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 5
·5821-5830
·
IF 2.478
Hu Peng,Deng Zhaoping,Wang Teshen,Li Zepeng,Ma Yanlin
In this study, a series of Eu 3+ -doped NaBaBi 2 (PO 4 ) 3 red phosphors were synthesized by high-temperature solid-phase reaction method, and the phase structure and photoluminescence properties of the samples were investigated in detail. All the diffraction peaks of the phosphors with various Eu 3+ concentrations are well matched with the NaBaBi 2 (PO 4 ) 3 standard phase, indicating that Eu 3+ ions have no effect on the host structure. Under the excitation of 391 nm wavelength, the emission spectra consisted of four characteristic emission peaks at 595, 617, 656 and 703 nm, respectively. The strongest emission peaking at 617 nm originates from the 5 D 0 → 7 F 2 electron transitions of Eu 3+ ions. The optimum concentration of Eu 3+ ions in NaBaBi 2 (PO 4 ) 3 :Eu 3+ is 9% concentration. The phosphor exhibits strong absorption capacity in the near-ultraviolet region. The Commission International de I’Eclairage chromaticity coordinates of the NaBaBi 2 (PO 4 ) 3 :Eu 3+ samples are located in the red region, indicating that the phosphors are suitable red component to applied in near-ultraviolet-based white light-emitting diodes.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 24
·9501-9510
·
IF 4.569
Jianhong Ding,Meng Kuang,Shuifu Liu,Ziheng Zhang,Kangrong Huang,Jiansheng Huo,Haiyong Ni,Qiuhong Zhang,Junhao Li
Developing novel luminescent materials with ideal properties is an endless project, urged by growing requirements of advances in energy saving, healthy lighting and environmental friendliness. Herein, a series of ScCaOBO3:Ce3+,Mn2+ phosphors with excellent luminescence properties were synthesized by the high temperature solid state method. X-ray diffraction was applied to analyse the phase composition of the obtained phosphors. The morphology and dopant distribution were observed by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS), respectively. The Rietveld refinements and luminescence spectra indicate that Ce3+ preferentially occupies the Sc3+ site and produces a blue emission band at around 460 nm, which originates from the characteristic 5d–4f transitions, while Mn2+ preferentially occupies the Ca2+ site and emits red light due to its characteristic 4T1(4G)–6A1(6S) transitions. Upon excitation at 354 nm, both Ce3+ and Mn2+ emissions can be obtained and further investigations evidenced that the broad and intense light emission of Mn2+ located in the red spectral region is the result of energy transfer from Ce3+ to Mn2+. Theoretical calculations reveal that the energy transfer process from Ce3+ to Mn2+ is of the resonance type and is governed by electric dipole–dipole interactions. Since the ScCaOBO3:Ce3+,Mn2+ phosphors are capable of producing broadband emissions that widely cover the blue and red spectral regions, the introduction of a green light-emitting phosphor CMA:Tb3+ can conveniently generate high quality white light. Therefore, a white light-emitting diode device with extremely high color rendering indices, Ra = 93.7 and R9 = 91.9, was successfully obtained.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Materials Chemistry Frontiers
·
2020
·Vol. 5
·期 2
·937-943
·
IF 6.788
Xupeng Gao,Xinyu Shen,Dingke Xue,Xin Li,Po Lu,Min Lu,Chunyan Li,William W. Yu,Xue Bai
Two-dimensional (2D) perovskites have become a research hotspot due to their large exciton binding energy and excellent stability. However, it is difficult to achieve longer wavelength emission than blue and green light in the 2D perovskites owing to their wide band gap resulting from their strong quantum confinement. Herein, we demonstrate a simple, efficient and low energy consumption crystallization method at room temperature to synthesize Mn2+ ion doped 2D (PEA)2PbBr4 nanocrystals (NCs) with dual-color emission centered at 410 nm from the exciton transition of the host and 600 nm from the d–d transition of Mn2+ ions. The periodic XRD peaks prove the formation of 2D perovskites. It is reassuring that the high PLQY of 54% has been achieved in the Mn2+ ion doped 2D (PEA)2PbBr4 NCs. The temperature-dependent and time-resolved spectra illustrate the efficient energy transfer from excitons to Mn2+ dopant ions. The realization of white LEDs with different color temperatures presents an opportunity and prospect for Mn2+ ion doped 2D perovskites in LED application.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Light-Science & Applications
·
2019
·Vol. 8
·期 1
·1-9
·
IF 14
Zhao Ming,Liao Hongxu,Molokeev Maxim S.,Zhou Yayun,Zhang Qinyuan,Liu Quanlin,Xia Zhiguo
Phosphor-converted white LEDs rely on combining a blue-emitting InGaN chip with yellow and red-emitting luminescent materials. The discovery of cyan-emitting (470–500 nm) phosphors is a challenge to compensate for the spectral gap and produce full-spectrum white light. Na 0.5 K 0.5 Li 3 SiO 4 :Eu 2+ (NKLSO:Eu 2+ ) phosphor was developed with impressive properties, providing cyan emission at 486 nm with a narrow full width at half maximum (FWHM) of only 20.7 nm, and good thermal stability with an integrated emission loss of only 7% at 150 °C. The ultra-narrow-band cyan emission results from the high-symmetry cation sites, leading to almost ideal cubic coordination for UCr 4 C 4 -type compounds. NKLSO:Eu 2+ phosphor allows the valley between the blue and yellow emission peaks in the white LED device to be filled, and the color-rendering index can be enhanced from 86 to 95.2, suggesting great applications in full-spectrum white LEDs.
研究领域:
材料科学
·
光学工程
·
固态照明技术
✓ 已验证
DOI
高影响因子
ACS Applied Optical Materials
·
2022
·
IF 0
Hongshi Zhang,Chaojie Li,Jiyou Zhong,Jun Wen,Weiren Zhao
The near-infrared (NIR) phosphor-converted light-emitting diode (pc-LED) is an emerging portable light source and has multifunctional applications based on spectroscopic technology. Nevertheless, it is still difficult to develop broadband NIR materials with strong resistance toward thermal quenching. In this work, a thermally robust broadband NIR phosphor NaGaP2O7:Cr3+ was reported, which has an emission peak located at 793 nm, and the emission spectrum covers 650–1100 nm with a full width at half-maximum (fwhm) of 115 nm. The emission intensity at 150 °C was surprisingly maintained as 85.45% of that at 25 °C, indicating an outstanding ability to resist thermal quenching. A systematic investigation of aspects such as structural rigidity, the band gap of the host, and the electron phonon coupling effect was carried out to understand the mechanism of thermally robust luminescence in this material. Finally, the NaGa0.94Cr0.06P2O7 NIR phosphor and 450 nm InGaN LED chip were combined to produce a prototype NIR light source. This device generates a NIR output power of 44.43 mW and a photoelectric conversion efficiency of 10.4% when driven at 150 mA, demonstrating a good performance of this material for practical applications.
研究领域:
材料科学
·
光学
·
固体物理
✓ 已验证
DOI
INORGANIC CHEMISTRY COMMUNICATIONS
·
2020
·
IF 1.943
Xiangjia Meng,Shuai Huang,Mengmeng Shang
Red-emitting phosphors have attracted considerable interest for their applications in warm white light-emitting diodes (LEDs). A series of novel red emitting Eu 3+ -doped Ba 2 GdVO 6 phosphors were prepared by a solid-state reaction annealed at 1300 °C for 6 h. Under the excitation of blue light (465 nm), Ba 2 GdVO 6 :Eu 3+ phosphors emit pure red light. The critical distance at which concentration occurs is determined to be 8.7 Å when the doping concentration reached up to 20 mol%. More importantly, the as-prepared Ba 2 GdVO 6 :20%Eu 3+ phosphor exhibit good thermal stability. The PL intensity at 150 °C remains 72% of its initial intensity at room temperature. The preliminary studies show that the Ba 2 GdVO 6 :Eu 3+ might be a promising red material for application in blue light converted warm white LED.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Kun Zheng,Xu Li,Mingjun Chen,Yi Gong,Aiwei Tang,Zhenguang Wang,Zhiren Wei,Li Guan,Feng Teng
According to mastery of solvent and reaction temperature, red, yellow, and blue emissive carbon nanodots (CNDs) with high quantum yield are successfully achieved using neutral red carbon source by solvothermal methods. The differences on the emission color of CNDs are evidently ascribed to conjugated absorption bands from n-π* transition confirmed by structural and optical characterizations. The results of quantum yield, transmission electron microscopy images, high magnification fluorescent micrographs of CNDs ethanol solution and solid-state CNDs & polyvinylpyrrolidone (CNDs&PVP) powders reveal that the obtained CNDs possess ultrahigh luminescence, favorable solubility, uniform dispersibility and well material compatibility. The bright fluorescent films were fabricated by mixing the CNDs &PVP composite powders with the epoxy. By taking advantage of these remarkable properties, the red, yellow, blue light-emitting diode was realized by combining CNDs&PVP film with a UV-LED chip. This work provides a new perspective for the explanation of the PL mechanism and the exploration of stable, high-performance, and environment-friendly multicolored CNDs-based LEDs.
研究领域:
材料科学
·
光学工程
✓ 已验证
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
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Feiyan Xie,Junqiang Gu,Shengqian Wang,Shengliang Zhong,Hualan Xu,Junhao Li
Phosphors for white light-emitting diodes (WLEDs) would suffer from inadequate luminescent thermal stability, especially at high temperatures, affecting both the reliability and lifespan of devices. Thus, the development of phosphors with excellent thermal stability is a crucial task. By use of a high-temperature solid-state reaction method, a series of Tb3+ and Eu3+ codoped NaGd2Ga3Ge2O12 (abbreviated as NGGGO) phosphors has been successfully synthesized. With an appropriate doping concentration of Tb3+ and Eu3+, the NGGGO:Tb3+,Eu3+ phosphors can provide color tunable emissions; simultaneously, the energy transfer (ET) efficiency from Tb3+ to Eu3+ can reach nearly 100%. Notably, high-concentration Tb3+ doping in NGGGO could induce oxygen vacancies, giving significant enhancement on the thermal stability of Eu3+ luminescence. For the NGGGO:60% Tb3+,1.6% Eu3+ phosphor, the emission intensity of Eu3+ at 450 K remained even higher than that observed under room-temperature conditions. By use of the as-synthesized phosphor as a red emission converter, a near-ultraviolet pumped WLED device can be fabricated. Under a driving current of 20 mA, the device exhibits high color rendering index (CRI) ∼ 89, low correlated color temperature (CCT) ∼ 4603 K, and bright white light with CIE chromaticity coordinates of (0.3569, 0.3587), which demonstrates the potential of NGGGO:Tb3+,Eu3+ phosphors in WLED application.
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
Materials Chemistry Frontiers
·
2025
·
IF 6.4
Lanxuan Yang,Lili Liu,Xu Ding,Ruili Xu,Tian Tian,Zhifu Liu,Lianjiang Tan,Yaoqing Chu
The asymmetry of the local environment within host materials plays a critical role in enhancing the emission performance of Eu3+ ions. In this study, we introduced a novel Si4+-doping strategy to optimize the luminous properties of Eu3+ ions by promoting asymmetry in the local lattice environment. And then, a series of Si4+/Eu3+ co-doped Sr3Ga2Ge4O14 phosphors were synthesized. Our findings reveal that Si4+-doping at a concentration of 60 mol% significantly enhances the emission intensity of Eu3+ ions in the Sr3Ga2Ge4O14 host by approximately 80%. Also, the internal quantum efficiency increases from 37.80% to 49.04%, alongside a rise in color purity from 87.40% to 99.80%. Utilizing this Sr2.3Ga2Ge1.6Si2.4O14:0.7Eu3+ high-performance red phosphor, we fabricated a white light-emitting diode (WLED) device with natural white light characteristics, achieving CIE coordinates of (0.338, 0.323), a correlated color temperature (CCT) of 5636 K, and a color rendering index (CRI) of Ra = 89.4. Additionally, we developed a high-performance anti-counterfeiting ink using this red phosphor, which adheres uniformly to surfaces with varying roughness and delivers exceptional luminescence effects. This study provides new insights into the development of advanced red-emitting phosphors for applications in lighting and anti-counterfeiting technologies.
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 RESEARCH BULLETIN
·
2024
·
IF 5.3
Huancheng Wu,Chaowei Yang,Xuejie Zhang,Bingfu Lei,Mingtao Zheng,Haoran Zhang
In this paper, a series of Ba2GaB4O9Cl:Ce 3+ ,Tb 3+ phosphors were synthesized by the conventional high-temperature solid-state reaction. The incorporation of Ce 3+ ions as sensitizers significantly enhances the absorption and luminescence intensity of Tb 3+ ions in the Ba 2 GaB 4 O 9 Cl phosphor. The energy transfer from Ce 3+ to Tb 3+ occurs through the electric quadrupole-quadrupole interaction, with an energy transfer efficiency of 48 %. The internal quantum efficiency of Ba 2 GaB 4 O 9 Cl:Ce 3+ ,Tb 3+ phosphor is 39.95 % upon 316 nm excitation. At 423 K, the emission intensity of Ba 2 GaB 4 O 9 Cl:Ce 3+ ,Tb 3+ can keep 53.28 % of its initial value at room temperature. All these results indicate that the Ba 2 GaB 4 O 9 Cl:Ce 3+ ,Tb 3+ phosphor has potential application for white LED.
研究领域:
材料科学
·
光学
✓ 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）