TETRAHEDRON
·
2018
·
IF 2.377
Yuqing Ma,Yuyang Zhang,Lin Kong,Jiaxiang Yang
Five quinoline derivatives containing different alkyl chains ( QLACn , n = 2, 4, 6, 8, 12) were synthesized to investigate the effect of alkyl chains on their photophysical properties. The fluorescent properties of the QLACn were affected by the alkyl chains, which indicated obvious blue-shifting trend and fluorescence emission are alkyl chains length-dependent by grinding-induced spectral shifts (Δλ MFC ). Longer alkyl-length revealed larger Δλ MFC . Powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) measurements indicated that the transformation between microcrystalline and amorphous states upon external stimuli should be responsible for the observed reversible MFC behavior.
研究领域:
材料科学
·
光物理学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2023
·
IF 4.5
Fuhua Gao,Wasim Ullah Khan,Zhiyuan Cheng,Waheed Ullah Khan,Iqtidar Ahmad,Zhiqi Ye,Shenghong Yang,Yueli Zhang
Broadband near-infrared (NIR)-emitting materials have critical applications in biology, medical detection, and NIR night-vision. However, developing NIR phosphors with promising optical properties and excellent thermal stability is a great challenge for research. In this work, a novel NIR phosphor Cr 3+ and Yb 3+ doped CaSc 2 O 4 (CSO) is an evolving NIR emitting phosphor with decent optical properties , boosted emission intensity, and thermal stability that makes it a promising candidate with potential applications in NIR-LED and infrared night-vision. The implications of the fundamental electronic structure of CSO, including valence-band (VB) and conduction-band (CB) orbital character, are investigated. Under blue light excitation, CSO:Cr 3+ is settled with pure broadband NIR emissions (max = 920 nm, FWHM (full width at half maximum) = ∼310 nm) and good thermal stability . The occupation of two selectable lattice sites of Cr 3+ in CSO is discussed in detail. Furthermore, emission enhancements of samples are done by Cr 3+ and Yb 3+ codoping, effectively broadening FWHM to 351 nm and reducing thermal quenching. The energy transfer (ET) routes in CSO:Cr 3+ ,Yb 3+ are investigated based on PL lifetime and comprehensive kinetic ET model, revealing that the PL enhancements by Cr 3+ and Yb 3+ codoping mainly originate from the ET from Cr 3+ to Yb 3+ emitters with more efficient and thermally stable. Finally, an InGaN-LED device encapsulated using CSO:0.01Cr 3+ and CSO:0.01Cr 3+ ,0.01 Yb 3+ phosphor was fabricated. The fabricated NIR pc-LEDs are excellent candidates for NIR light sources in biological imaging and NIR night vision.
研究领域:
光学材料
·
生物医学成像
·
光电子学
·
无机发光材料
·
红外技术
·
固态照明
·
纳米生物技术
✓ 已验证
DOI
高影响因子
Laser & Photonics Reviews
·
2023
·Vol. 17
·期 10
·2300158
·
IF 11
Gangyi Zhang,Deyin Wang,Jiejun Ren,Xiaopeng Zhou,Yuhua Wang
Luminescent metal halides have attracted increasing attention because of their tunable emission and superior photoelectric properties. However, it is still challenging to achieve near-infrared (NIR) emission from metal halides, which is important in applications such as food quality analysis and night vision. In this work, the broadband NIR emission is achieved by alloying Sn 2+ into zero-dimensional (0D) Cs 2 ZnBr 4 . The incorporating of Sn 2+ cations enables the originally weakly luminescent Cs 2 ZnBr 4 to exhibit an efficient broadband NIR emission. Upon photoexication, the optimized Sn 2+ alloyed Cs 2 ZnBr 4 (Cs 2 Zn 0.875 Sn 0.125 Br 4 ) exhibits a highly efficient broadband NIR emission peaked around 700 nm, with a large Stokes shift of 323 nm, a full width at maximum of 177 nm, and a high quantum efficiency of around 41%. Spectroscopic and theoretical calculations unveil that the efficient NIR emission originates from the self-trapping emission introduced by the Sn alloying. In addition to the high efficient broadband emission, the Sn 2+ alloyed Cs 2 ZnBr 4 also exhibits high thermal stability, retaining 78% of its initial intensity at 150 °C. The night vision application is demonstrated by using a light source fabricated by combining Sn 2+ alloyed Cs 2 ZnBr 4 phosphor with a 365 nm LED chip in the dark.
研究领域:
材料科学
·
光电子学
·
无机化学
·
固态物理
·
光学材料
✓ 已验证
DOI
高影响因子
Small
·
2024
·Vol. 20
·期 40
·2400578
·
IF 13
Yike Du,Aotian Li,Fan Zhang,Han Gao,Xuan Zhou,Jiliang Zhu,Zhicheng Ye
Passive radiative cooling (PRC) can spontaneously dissipate heat to outer space through atmospheric transparent windows, providing a promising path to meet sustainable development goals. However, achieving simultaneously high transparency, color-customizable, and thermal management of PRC anti ultraviolet (anti-UV) films remains a challenge. Herein, a simple strategy is proposed to utilize liquid crystalline polymer, with high mid-infrared emissive, forming customizable structural color film by molecular self-assembly and polymerization-induced pitch gradient, which guarantees the balance of transparency in visible spectrum and sunlight reflection, rendering anti-UV colored window for thermal management. By performing tests, temperature fall of 5.4 and 7.9 °C are demonstrated at noon with solar intensity of 717 W m −2 and night, respectively. Vivid red-, green-, blue-structured colors, and colorless films are designed and implemented to suppress the solar input and control the effective visible light transmissivity considering the efficiency function of human vision. In addition, temperature rise of 11.1 °C is achieved by applying an alternating current field on the PRC film. This study provides a new perspective on the thermal management and aesthetic functionalities of smart windows and wearables.
研究领域:
材料科学
·
高分子化学
·
光学工程
·
能源材料
·
纳米科技
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2020
·Vol. 8
·期 22
·2001037
·
IF 8.286
Dongjie Liu,Xiaohan Yun,Guogang Li,Peipei Dang,Maxim S. Molokeev,Hongzhou Lian,Mengmeng Shang,Jun Lin
Highly efficient cyan-emitting phosphor materials are indispensable for closing the cyan gap in spectra of the traditional phosphor-converted white light-emitting diodes (WLEDs) to achieve high-quality full-spectrum white lighting. In this work, bright cyan-emitting Ca 3 Ga 4 O 9 (CGO):0.02Bi 3+ ,0.07Zn 2+ phosphor is developed to bridge the cyan gap. Such a Bi 3+ ,Zn 2+ codoping enhances the cyan emission of CGO:0.02Bi 3+ by 4.1 times due to the influence of morphology and size of phosphor particles, charge compensation and lattice distortion. Interestingly, codoping La 3+ ions into the current system can achieve a photoluminescence tuning of CGO:0.02Bi 3+ from cyan to yellowish-green by crystallographic site engineering. Besides, Bi 3+ –Eu 3+ energy transfer is successfully realized in CGO:0.02Bi 3+ ,0.07Zn 2+ , n Eu 3+ phosphors and the emission color tuning from cyan to orange is observed. The investigation of thermal quenching behaviors reveals that the incorporation of Zn 2+ and La 3+ improves the thermal stability of CGO:0.02Bi 3+ . Finally, CGO:0.02Bi 3+ ,0.07Zn 2+ ,0.10Eu 3+ phosphor is employed to obtain a single-phased warm WLED device. A full-spectrum WLED device with remarkable color rendering index (Ra) of 97.4 and high luminous efficiency of 69.72 lm W −1 is generated by utilizing CGO:0.02Bi 3+ ,0.07Zn 2+ phosphor. This result suggests the important effect of CGO:0.02Bi 3+ ,0.07Zn 2+ phosphor on closing the cyan gap, providing new insights of cyan-emitting phosphors applied in full-spectrum white lighting.
研究领域:
材料科学
·
光学工程
·
固体物理
·
无机化学
·
光电子学
·
照明技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2017
·Vol. 33
·期 8
·850-855
·
IF 2.764
Nannan Bi,Lei Zhang,Qiang Zheng,Fei Zhuge,Jiupeng Li,Xuan P.A. Gao,Juan Du
A vapor deposition method was applied to synthesize zinc oxide (ZnO) nanowires and nanorods with diameter from 40 nm to 500 nm, length from 1 μm to 70 μm by adjusting the flow rate of argon, oxygen and the pressure during growth. Results of scanning electron microscopy (SEM) and high resolution transmission electron microscopy (TEM) proved the hexagonal wurtzite structure of the synthesized ZnO nanowires or nanorods , which grow along the <0001> direction. The results show that the growth conditions strongly impact the morphology, growth rate and optical properties of the ZnO nanostructures . The ZnO nanowires with small diameters tend to show stronger ultraviolet (UV) light emission from the electron-hole recombination near band edge in photoluminescence (PL), while those with larger diameters tend to exhibit PL spectra dominated by the broad green light emission due to the defects.
研究领域:
材料科学
·
纳米技术
·
半导体物理
·
光电子学
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Yaping You,Ya Zheng,Zesheng Pan,Yunluo Wang,Tianrui Zhou,Minghui Wang,Haijie Chen,Wan Jiang,Lianjun Wang
White light-emitting diode (WLED) has been widely used as solid-state lighting in recent years, with the advantages of energy saving, high luminous efficiency , and safety. Red phosphors are crucial to the color rendering index of WLED, and Eu 3+ -activated red phosphors can significantly improve the chromaticity performance of WLED. In this work, a series of new orange-red emitting BaLiZn 3 (PO 4 ) 3 : Eu 3+ phosphors were synthesized through high-temperature solid-state reaction method. The phase composition , crystal structure, morphology and photoluminescence properties of BaLiZn 3 (PO 4 ) 3 : Eu 3+ samples were investigated. The phosphors can be effectively excited by the violet light at 394 nm and emit orange-red lights corresponding to the electric dipole transition (5D 0 →7F 1 ) at 594 nm. The optimal doping concentration of Eu 3+ ions was about 5 mol%. The concentration quenching was caused by the electric dipole-dipole interaction between Eu 3+ ions. Temperature-dependent PL spectra indicate that BaLiZn 3 (PO 4 ) 3 : Eu 3+ has excellent emission and color stability at high temperatures. The color coordinates were calculated and fall in the orange-red luminescent area. The color purity is about 98.3 %, and the correlated color temperature is 1710K. These results indicate that the new orange-red phosphor BaLiZn 3 (PO 4 ) 3 : Eu 3+ has potential application prospects in WLED.
研究领域:
材料科学
·
发光材料
·
固体照明
·
无机化学
·
光电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Zhiqin Zheng,Peizhang Xie,Panpan Yi,Jun Zhao,Lihong Liu,Facheng Yi
Nowadays, ultraviolet (UV) and blue converted phosphors have played a key role in the solid-state lighting field, and the white light is usually produced by mixing multiple phosphors. In this work, we report a type of UV converted single white phosphor, i.e. , Ba 9 La 2 Si 6 O 24 :Eu 3+ ,Bi 3+ .Various techniques, such as powder X-ray diffraction (XRD), scanning electron microscopic (SEM), photoluminescence (PL) spectra, and quantum efficiency (QE), have been used to characterize the samples. In Bi 3+ doped samples, upon excitation within the wavelength range of 250–380 nm can lead to three Bi 3+ emission bands ( i.e. , 358 nm, 415 nm, and 516 nm), but only one emission band peaking at 415 nm appears when the excitation wavelength exceeds 380 nm. Structural analysis and discussion on the PL intensity variation reveal there are three Bi 3+ luminescent centers at two different La 3+ sites and one Ba 2+ site. The Bi 3+ concentration-induced luminescent quenching is dominated by the d-d interaction. In view of the spectral overlap between the Bi 3+ emissions and the Eu 3+ excitation spectra , the energy transfer from Bi 3+ to Eu 3+ of the Ba 9 La 2 Si 6 O 24 :Eu 3+ ,Bi 3+ is studied, and it is dominated by a dipole-quadrupole ( d - q ) interaction. Moreover, upon excitation at 365 nm, the emissions broadly tuning from blue, white and to red are achieved by varying the Eu 3+ content. For the white Ba 9 La 2 Si 6 O 24 :Eu 3+ ,Bi 3+ sample, high temperature PL results show that it does not have severe degradation of emission intensity after increasing the temperature from 25 to 300 °C, exhibiting a good thermal stability . To show the potential application in the lighting fields, we fabricate a white light LEDs device by depositing this white phosphor on a 365 nm UV LED chip. As a result, the values, i.e. , a color rendering index (CRI) of 95, luminous efficiency of 80 lm/W, and color temperature (CT) of ~4215 K at chromaticity (0.382, 0.398), are achieved.
研究领域:
材料科学
·
发光材料
·
固态照明
·
无机化学
·
光电子学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2023
·
IF 5.4
Zhihao Zhang,Huimin Li,Ran Pang,Wenjing Wang,Da Li,Lihong Jiang,Su Zhang,Hongjie Zhang
Phosphor-converted light emitting diodes (pc-LEDs) are essential for current lighting and display areas because of their unique properties of being uncomplicated, durable and economical. In previous studies, Pr 3+ doped red-emitting phosphors have attracted enormous research interest due to their high color purity. However, their photoluminescence excitation (PLE) spectra are always hard to be combined with LED chips. This mismatch is a great obstacle to achieve Pr 3+ phosphors utilizing in LED devices. Here, to circumvent this issue, Pr 3+ -doped Ca 3 MgTiGe 3 O 12 (CMTG) red-emitting phosphor was optimized with PLE band shifting from 330 nm to 360 nm after tuning with Bi 3+ co-doping based on the structure and phosphorescence properties. The chip-matched excitation makes it a good candidate for white LEDs (wLEDs) fabrication to improve the output quality of device. Meanwhile, the high color purity of 93.02 % was obtained, which is conducive to widening the color gamut of backlight display applications. The photoluminescence (PL) spectra, fluorescence lifetime, and X-ray photoelectron spectroscopy (XPS) analysis were employed and discussed in detail to explain the role of Bi 3+ played in the system. Finally, wLEDs were fabricated with CMTG:Pr 3+ , Bi 3+ , showing a high color rendering index (Ra) of 94.4. And the color gamut covers ∼80 % of the National Television System Committee (NTSC) standard, suggesting great potential for applications of wLEDs and backlight display.
研究领域:
材料科学
·
发光材料
·
固态照明
·
显示技术
·
无机化学
·
光电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 18
·1251
·
IF 2.8
Zheng Jinjie,Shen Honglie,Li Yufang,Li Hechao,Yue Zhen
Novel efficient visible and near-infrared emitting phosphors NaY(MoO 4 ) 2 (NYM):Ln 3+ (Ln = Ce and Yb) were proposed in this work. The crystal structure, lattice vibration characteristics, morphology, and luminescent properties of NaY(MoO 4 ) 2 phosphors were described. Sensitization of Ln 3+ from the host with various doping concentrations was investigated. The yellow-green emission was achieved in Ce 3+ single-doped NYM phosphors at UV ultraviolet excitation sensitized by the MoO 4 2− group. Under UV excitation, characteristic emissions of Ce 3+ at 400–700 nm and Yb 3+ at 1000 nm of NYM:Ce,Yb were observed, enabling the spectral down-conversion applications. With the increasing concentration of Yb 3+ , the emission intensity as well as the lifetime of Ce 3+ decreased, confirming the energy transfer from Ce 3+ ions to Yb 3+ ions. And the energy transfer coefficient was 27% for NYM:0.01Ce,0.10Yb phosphor. These results indicate that the as-prepared phosphors have potential applications in optical and photonic devices.
研究领域:
材料科学
·
光学材料
·
发光学
·
无机化学
·
光子学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2024
·Vol. 27
·期 5
·661-667
·
IF 2.6
Zhen-Dong Xue,Yi Zhang,Hao-Yu Zhu,Juan-Juan Shao,Qiang Gao,Fang-Ming Wang
Herein, four new cuprous iodide hybrid materials 1–4 were synthesized at room temperature using two types of ligands: imidazoles and triphenylphosphine. Photoluminescence results showed that all the materials exhibited blue emissions with high internal quantum yields (IQYs) ranging from 51% to 64%. Surprisingly, the introduction of triphenylphosphine induced strong aggregation-induced emission (AIE). Additionally, the luminescence lifetimes of these materials were significantly longer, ranging from 11.53 μs to 24.33 μs, which is much longer than those of previous materials. These findings suggest that these materials could be potential candidates for non-rare earth element (REE) lighting phosphors.
研究领域:
材料化学
·
光物理
·
无机-有机杂化材料
·
发光材料
·
非稀土磷光体
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2015
·
IF 2.288
J.L. Wang,E.H. Song,M. Wu,W.B. Dai,S. Ye,Q.Y. Zhang
Selectively enhanced green upconversion (UC) and near-infrared (NIR) downconversion (DC) emissions of Er 3+ by Yb 3+ -Mn 2+ dimer sensitizing have been demonstrated in Er 3+ /Yb 3+ /Mn 2+ tri-doped spinel MgGa 2 O 4 upon excitation of 980 nm laser diode (LD). By optimizing the doping rate of Mn 2+ , the intensity ratio of green to red UC emission intensities of Er 3+ (G/R) could be enhanced about 10 times. Meanwhile, the 1.5 μm NIR DC emission could also be increased about 3.6 times in this system. The DC and UC emission properties, UC mechanism, as well as the enhancing mechanism have been investigated and discussed in detail. A selectively enhancing mechanism based on Yb 3+ -Mn 2+ dimer sensitizing is proposed to explain the selectively enhancing phenomena. This work could inspire the design of novel UC materials for various applications, such as temperature sensors and optical transmission, etc.
研究领域:
光学材料
·
生物医学光子学
·
无机功能材料
·
分子影像
·
转化医学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）