MATERIALS RESEARCH BULLETIN
·
2023
·
IF 5.4
Yu Zhang,Kai Li,Xuelian Zhou,Kaixuan Wang,Ze Wang,Sur Lig,Kefu Chao,Fengqi Zhao
Cr 3+ -doped near-infrared phosphors have recently attracted a wide attention. Here, NIR Ca 1- y Sr y Al 12- x Ga x O 19 :0.12Cr 3+ phosphors are obtained by a high-temperature solid-phase method. First, a series of CaAl 7.88 Ga 4 O 19 :0.12Cr 3+ samples is studied and shows that the crystal field strength can be tuned by cation substitutions, until achieving a sharp emission at 692 nm and a broad emission at 780 nm under a 400 nm excitation, and an internal quantum yield of 90.73%. A further substitution by an appropriate amount of Sr 2+ is suggested to be beneficial to increase the rigidity of the crystal structure by Debye temperature calculations. Experimentally, it is observed that Sr 2+ for Ca 2+ substitutions did not affect the luminescence wavelength and resulted in a significant increase of the thermal stability. When 0.7 Sr 2+ substitute Ca 2+ , the thermal stability at 450 K increased by 28% compared to the samples without Sr 2+ .
研究领域:
材料科学
·
无机化学
·
固体物理
·
光学材料
·
功能材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 46
·期 12
·20173-20182
·
IF 3.83
Shujie Gai,Haifeng Zhu,Peixin Gao,Cheng Zhou,Zihui Kong,Maxim S. Molokeev,Zhiyong Qi,Zhi Zhou,Mao Xia
Currently, phosphor-converted LEDs (pc-LEDs) are revolutionizing the industry of plant growth lighting. To meet the requirements of this technology, phosphors with tunable photoluminescence , high thermal stability and luminous intensity are required. Herein, we found that the simple substitution of yttrium for lanthanum in La 2 MgTiO 6 :Mn 4+ (LMT:Mn 4+ ) system could satisfy above three criteria simultaneously. The photoluminescence properties can be regulated by continuously controlling the chemical composition of La 2-x Y x MgTiO 6 :Mn 4+ solid solution . The La sites are occupied by Y ions , causing a significant blue shift in the emission spectra which owing to the change of local crystal field strengthen. Meanwhile, the thermal stability and decay lifetimes are also varied due to the variation of local structure and band gap energy. The thermal stability of the material reaches 83.5% at 150 °C, which is better than the reported La 2 MgTiO 6 :Mn 4+ and Y 2 MgTiO 6 :Mn 4+ phosphors. The electronic luminescence (EL) of pc-LED devices using La 2-x Y x MgTiO 6 :Mn 4+ red phosphor is evaluated, which matching the absorption regions of plant pigments well, reflecting the superiority of the studied phosphors in plant growth lighting areas.
研究领域:
材料科学
·
光电子学
·
无机化学
·
农业工程
·
固体物理
·
发光材料
·
植物生理学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Jiang Wu,Haowen Bai,Wenjie Qu,Guanying Cao,Yanjie Zhang,Jingjie Yu
CsPbBr 3 quantum-dot borosilicate microcrystals and Eu 3+ -doped CsPbBr 3 quantum-dot microcrystals with different concentrations of Eu 3+ are successfully prepared by high temperature melting. The particle morphology of the microcrystals is characterized by scanning electron microscopy (SEM). The fluorescence characteristics are analyzed by fluorescence spectroscopy and CIE chromaticity coordinates . In this research, CsPbBr 3 quantum dots are effectively coated with borosilicate microcrystals to improve the stability of CsPbBr 3 quantum dots while ensuring its strong green emission at 517 nm. The energy transfer from CsPbBr 3 quantum dots to Eu 3+ occurs after doping. When changing the concentration of Eu 3+ , the emission peaks of perovskite broaden and blue shift occurs (517 nm→474 nm). The CIE color coordinate moves from (0.0807, 0.7200) to (0.4537, 0.2724). Therefore, the continuous adjustment of solid perovskite materials from green light to blue light and then to red light region is realized.
研究领域:
材料科学
·
纳米光学
·
无机非金属材料
·
光电子学
·
发光材料
·
固态化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 38
·22064-22071
·
IF 12.732
Wenda Zhang,Jie Feng,Fengqi Lu,Alberto J. Fernández-Carrión,Hui Fu,Xiaojun Kuang
Na-doped melilite-type silicate Sr2MgSi2O7 was reported to display high oxide ion conductivity. In this work, through multiple complementary techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, solid-state 29Si and 23Na nuclear magnetic resonance spectroscopy, and DFT calculations of defect formation energies, we found that it is hard to replace Sr with Na in Sr2MgSi2O7, and the Sr2−xNaxMgSi2O7−0.5x compositions formed mixed crystalline Sr2MgSi2O7 and Na-containing glassy phases. AC impedance spectroscopy measurements indicated that the ionic conduction in Sr2−xNaxMgSi2O7−0.5x could be from Na+ ions in the glassy phase, instead of the oxide ions.
研究领域:
材料科学
·
固体离子导体
·
无机非金属材料
·
能源材料
·
电化学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2019
·Vol. 125
·期 3
·158
·
IF 1.784
Gao Dong-Sheng,Gao Xiang-Dong,Wu Yong-Qing,Zhang Tong-Tong,Yang Jing-Nan,Li Xiao-Min
Co doped BaSnO 3 films [BaSn 1 − x Co x O 3 (0 ≤ x ≤ 0.50), i.e., BSCO] have been grown on MgO single-crystal substrates via pulsed laser deposition. Effects of the Co-doping level on the crystallinity, the microstructure, and optical properties of the BSCO films are investigated. All the BSCO films are of high crystallinity and grown epitaxially on MgO substrates. The lattice parameter of the (200) plane drops linearly with the increase of the ‘ x ’ value. The Co doping is found to increase the film roughness and the grain size, and a RMS roughness of 8.33 nm and grain size up to 100 nm are observed in the film with x = 0.50. The low Co-doping level ( x = 0.05, 0.1) has slight anti-reflection effects on the incident visible light, and the Co-doping level higher than 0.2 reduces the optical transmittance significantly. The optical bandgap shows a first-rising then falling trend with the increase of the Co content, and the lowest bandgap of 1.94 eV is realized in the BSCO film with x = 0.50.
研究领域:
材料科学
·
凝聚态物理
·
薄膜制备
·
光学材料
·
功能氧化物
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2016
·Vol. 18
·期 28
·19165-19172
·
IF 4.449
Lihong Bao,Xiaoping Qi,Tana,Lumen Chao,O. Tegus
Multiple nanocrystalline rare-earth hexaborides La1−xBaxB6 have been synthesized via a single step solid-state reaction. The Ba doping effects on crystal structure, grain morphology, magnetic and optical absorption properties were investigated using XRD, FESEM, HRTEM, SQUID magnetometry and optical measurements. The results show that all the Ba-doped hexaborides crystallize in the CsCl-type single phase, indicating the Ba atoms occupied the lattice sites of LaB6. The optical absorption results indicate that the absorption valleys of LaB6 are red-shifted from 622 nm to 780 nm when the Ba doping content increases to x = 0.8. The first-principle calculation results reveal that Ba doping reduces the total kinetic energy of the electrons of LaB6, which lead to the absorption valleys moving toward a higher wavelength. Meanwhile, the band gap of BaB6 obtained from optical absorption is in good agreement with the theoretical calculation results. The magnetic measurements results showed that Ba doping lead to room-temperature ferromagnetism of LaB6 due to the different ionic radii of La3+ and Ba2+ causing intrinsic crystal defects, which is directly observed experimentally by HRTEM. This is the first time that we have found the tunable optical and ferromagnetic behavior of Ba doped nanocrystalline LaB6. Thus, nanocrystalline La1−xBaxB6, as multi-functional materials, should open up a new route to extend the optical and magnetic applications of LaB6 nanopowder.
研究领域:
材料科学
·
凝聚态物理
·
纳米材料
·
功能材料
·
磁学
·
光学材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Kuan Wu,Gang Xu,Dengyu Pan,Minghong Wu
Combination of high-capacity and flexibility in electrode materials is crucial for flexible electronics. Recently, red phosphorus (P) has caused increasing focus as a hopeful storage material for lithium storage due to its super-high theoretical capacity and low cost. However, the low conductivity of red P and its large volume change during cycling process lead to reduced electrochemical activity. So far, no effective methods have been developed to construct flexible binder-free electrodes using red P as an active material for high-performance lithium-ion batteries (LIBs). Here, a novel hollow three‐dimensional (3D) internet structure as a flexible high-areal-capacity electrode material was fabricated by confining red P nanoparticles into compact MOF-derived carbon-based composite polyhedrons/carbon nanotube internets. The electrode manifests an excellent lithium storage performance for LIBs with a high discharge capacity of 4.78 mAh cm −2 (1920 mAh g −1 ) at 0.1 mA cm −2 and a good capacity retention of 79.2% at 1 mA cm −2 after 300 cycles (73% and 69% capacity retention at 5 and 10 mA cm −2 after 500 cycles, respectively). The novel flexible anode materials can provide excellent Li + storage performance for flexible electronics applications.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
功能材料
·
先进电池技术
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2017
·
IF 2.446
Tengchao Guo,Guoyue Xu,Shujuan Tan,Ning Liu,Jianchao Zhang,Xiangxiong Zeng,Juan Liang
The electronic properties and infrared emissivity of Zn 1-x Mg x O (x = 0, 0.0625, 0.125) were systematically investigated by using the first-principle calculation s based on density functional theory (DFT). The Zn 1-x Mg x O (x = 0, 0.0625, 0.125) powders were prepared by sol-gel method and their infrared emissivity in the wavelength of 8–14 μm was characterized. The results indicate that the infrared emissivity increases with the increase in Mg concentration, which is attributed to the reduction in conductivity and in the real part of dielectric function. Furthermore, the variation in conductivity and dielectric function has been well studied, and a reasonable method to calculate infrared emissivity of semiconductors has been established. It is expected that this method can be used for designing materials with different infrared emissivity and also applied for effectively guiding the experimental investigation.
研究领域:
材料科学
·
凝聚态物理
·
计算材料学
·
功能材料
·
半导体物理
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2019
·Vol. 40
·期 5
·631-637
·
IF 4.914
Zhenmin Xu,Ru Zheng,Yao Chen,Jian Zhu,Zhenfeng Bian
Ordered mesoporous Fe/TiO 2 was prepared by an evaporation-induced self-assembly method. The iron ions were in situ embedded in the pore wall of the TiO 2 framework. The catalyst has excellent light-assisted Fenton catalytic performance under UV and visible light irradiation. X-ray diffraction and transmission electron microscopy results showed that the TiO 2 samples have an ordered two-dimensional hexagonal pore structure and an anatase phase structure with high crystallinity . The ordered pore structure of the TiO 2 photocatalyst with a large specific surface area is beneficial to mass transfer and light harvesting. Furthermore, iron ions can be controlled by embedding them into the TiO 2 framework to prevent iron ion loss and inactivation. After five cycles, the reaction rate of the ordered mesoporous Fe/TiO 2 remained unchanged, indicating that the material has stable performance and broad application prospects for the purification of environmental pollutants .
研究领域:
材料科学
·
环境化学
·
催化化学
·
纳米科技
·
光化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 50
·期 4
·6598-6605
·
IF 5.2
Wei Peng,Jianglei Chang,Bin Wang,Zhen Liu,Genshui Wang,Shuxiang Dong
The ultrahigh piezoelectric coefficient (d 33 ≥ 1000 pC/N) exhibited by piezoelectric Pb(Zr,Ti)O 3 (PZT) ceramics not only captivates researchers but also holds considerable practical value across various applications. While significant progress has been made in enhancing piezoelectricity of PZT-based ceramics, novel mechanisms need to be proposed to explain the piezoelectric behavior of new systems with ultrahigh d 33 . In this study, we initially employ LiNbO 3 as an additive to enhance the piezoelectric properties of the Pb(Ni 1 / 3 Nb 2 / 3 )O 3 –PbZrO 3 –PbTiO 3 ceramics. and the optimal performance is achieved by incorporating 1.5 mol% of LiNbO 3 into the system, resulting in an ultrahigh d 33 ∼1178 pC/N ( d 33 * ∼1560 p.m./V (@ E = 5 kV/cm)). The corresponding mechanism for this superior piezoelectric response involves the AB-site co-doping effect, especially the ( Li Pb ′ − Nb Zr / Ti ∙ ) defect dipoles formed by the introduction of LiNbO 3 . In particular, the addition of LiNbO 3 leads to a more uniform distribution of domain sizes, thereby further enhancing the ultrahigh piezoelectricity. These findings pave the way for a deeper under-standing of the origin of ultrahigh piezoelectric properties and make substantial contributions to the advancement of piezoelectric materials for practical applications in electromechanical devices.
研究领域:
材料科学
·
功能陶瓷
·
压电材料
·
固态物理
·
电子显微学
·
介电材料
·
无机非金属材料
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2017
·Vol. 27
·期 2
·413-418
·
IF 2.594
Yanyun Zhang,Xichuan Yang,Weihan Wang,Xiuna Wang,Licheng Sun
X1 (MeO-TPD) is an inexpensive and easily synthesized π -conjugated molecule that has been used as a hole-transport material (HTM) in solid-state dye-sensitized solar cells (ssDSSCs), achieving relatively high efficiency. In this paper, we characterize the physicochemical properties of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and show that it is a promising p-dopant in a spin-coating solution with X1 as the HTM. The doped ssDSSCs showed an increase in short-circuit current density from 5.38 mA cm –2 to 7.39 mA cm –2 , and their overall power conversion efficiency increased from 2.9% to 4.3%. Also, ssDSSCs with DDQ-doped X1 were more stable than the undoped samples, demonstrating that DDQ can act as a p-type dopant in X1 as an HTM for highly efficient, stable ssDSSCs.
研究领域:
材料科学
·
能源化学
·
光伏技术
·
纳米材料
·
半导体器件
·
表面化学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Chuanying Wang,Xianhua Cheng
β-NaYF 4 :Yb 3+ /Er 3+ microcrystals codoped with Cr 3+ ions were prepared for the first time via a facile hydrothermal method . The influence of doping concentration of Cr 3+ ions on growth and upconversion (UC) luminescence properties of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals were investigated in detail. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra and photoluminescence (PL) spectra were used for characterization. The results demonstrated that the morphology and size of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals were influenced by doping concentration of Cr 3+ ions, the possible mechanism was proposed. The UC intensity of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals was significantly enhanced by doping of Cr 3+ ions. In contrast to β-NaYF 4 :Yb 3+ /Er 3+ microcrystals without doping of Cr 3+ ions, the green and red emission intensities of the microcrystals codoped with 15 mol% Cr 3+ ions were enhanced by 16 and 7 times, respectively. The enhancement of the UC intensities should be ascribed to the distortion of local symmetry around Er 3+ ions, the UC mechanism was discussed. This work will be helpful for improving the UC intensity of other lanthanide-doped UC nano- and micro-crystals.
研究领域:
材料科学
·
无机化学
·
光功能材料
·
纳米医学
·
生物成像
·
分子影像学
·
光学材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）