OPTICAL MATERIALS
·
2016
·
IF 2.183
Renping Cao,Xiangfeng Ceng,Jijun Huang,Hui Ao,Guotai Zheng,Xiaoguang Yu,Xinqin Zhang
A double perovskite Sr 2 ZnMoO 6 :Mn 4+ (SZM:Mn 4+ ) phosphor is synthesized by high-temperature solid-state reaction method in air. Emission band peaking at ∼705 nm of SZM:Mn 4+ phosphor in the range of 650–790 nm is attributed to the 2 E → 4 A 2 transition of Mn 4+ ion with activated different lattice vibration modes. Three excitation bands in the range of 210–610 nm are assigned to the O 2− → Mn 4+ charge transfer and the 4 A 2 → ( 4 T 1 , 2 T 2 , and 4 T 2 ) transition of Mn 4+ ion. The optimal Mn 4+ ion concentration is ∼0.8 mol% in SZM:Mn 4+ phosphor. Fluorescence lifetime of SZM:Mn 4+ phosphor decreases from ∼132 μs to 108 μs with increasing Mn 4+ ion concentration in the range of 0.2–1.0 mol%. Time-resolved spectra and fluorescence lifetime data indicate that luminescent center is caused by Mn 4+ ion. The luminous mechanism of SZM:Mn 4+ phosphor is explained by Tanabe-Sugano energy level diagram of Mn 4+ ion. The results are useful to understand the influences of the neighboring coordination environment around Mn 4+ and host crystal structure to the luminescence properties of Mn 4+ ion and develop other novel Mn 4+ -doped materials.
研究领域:
材料科学
·
无机化学
·
固体物理
·
发光材料
·
光电功能材料
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2010
·Vol. 257
·期 9
·3920-3923
·
IF 1.616
Hongxu Guo,Jianhua Chen,Wen Weng,Shunxing Li
A visible light-driven photocatalyst, C-doped Zn 3 (OH) 2 V 2 O 7 , prepared by a hydrothermal method was studied. The as-prepared catalyst was characterized by SEM, XRD , DRS, and XPS , and exhibited efficient photocatalytic activity in the degradation of methylene blue (MB) under visible-light irradiation. Besides decoloring, the decomposition of MB was also observed, further demonstrating the performance of the photocatalyst. The carbon existing on the surface of Zn 3 (OH) 2 V 2 O 7 nanorods was free and in carbide form. Dye degradation followed first-order kinetics, and was explained on the basis of the Langmuir–Hinshelwood mechanism.
研究领域:
材料化学
·
光催化
·
纳米材料
·
环境化学
·
无机合成
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2014
·Vol. 32
·期 8
·686-690
·
IF 1.342
LIU Lisha,CHEN Haohong,LIU Biqiu,ZHANG Hui,TANG Bin,FENG Xianjuan,SUN Zhijia,ZHAO Jingtai
To explore novel nano-scintillator with a controllable architecture, pure and Eu 3+ doped lutetium oxyfluoride (Lu 7 O 6 F 9 ) powder were synthesized by combining mild hydrothermal method and solid state calcination approach. The products were all pure orthorhombic Vernier phase demonstrated by X-ray powder diffraction (XRD). The detailed crystal structure was also studied by Reitveld refinement. Lath-like microcrys tals composed of nanoparticles with unique hollow tube of the products were supported by the images of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Excited by X-ray with W as the target, the pure product showed intense broad emission with the peak at about 400 nm suitable for modern photoelectric multiplier tube (PMT), while the Eu 3+ doped sample transferred the incident energy to Eu 3+ ions and gave strong 5 D 0 → 7 F j ( j =0, 1, 2 and 4) emission, which fitted for imaging and labeling measurements. From the luminescent properties, both pure and Eu 3+ -doped products are potential excellent scintillator for X-ray imaging and other high energy detectors, and the pure product is also a good host candidate for rare earth doping.
研究领域:
材料科学
·
无机化学
·
发光材料
·
纳米医学
·
生物成像
·
辐射探测
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2023
·
IF 4.1
Kang Cheng,Xinyue Liu,Weichao Huang,Xinyong Gong,Chaoyong Deng
Cr 3+ is an ideal activator for near-infrared phosphor. Cr 3+ ions have an electronic structure in which the outermost shell is not fully filled, which makes the emission of Cr 3+ susceptible to the crystal field environment and the change of local structural. Therefore, when Zn 2+ -Ti 4+ ion pairs are replaced with Al 3+ -Al 3+ /Ga 3+ -Ga 3+ ion pairs , changes in the crystal structure and the crystal field are strengthened, which improves the luminescence performances of Zn 2 TiO 4 :Cr 3+ phosphors. The thermal stability and the intensity of the luminescence can be clearly seen to have increased.
研究领域:
材料科学
·
无机化学
·
发光材料
·
固体物理
·
功能材料
✓ 已验证
DOI
高影响因子
Journal of Materiomics
·
2024
·Vol. 11
·期 4
·100995
·
IF 8.4
Yuqing Sun,Zhihao Li,Yujie Zong,Fulong Liu,Hongxiang Wang,Hui Sun,Chunlei Wang,Hongchao Wang
The intrinsic low lattice thermal conductivities originates from the complex anion bonding environment make quaternary chalcogenides potential thermoelectric materials. Here, the bonding environment of Se atom in Cu 2.1 Mn 0.9 SnSe 4 is further regulated by substituting Mn 2+ with equimolar pairing elements (Ag + and In 3+ ). The increase in both bond length and angle, together with the reduction in bond strength of Ag Se and In Se bonds, cause the doped samples to display strong anharmonicities ( γ ∼ 1.84–2.04). And the weakened bond strength also lower the sound velocities. Consequently, the κ L of the doped samples is effectively constrained, achieving a minimum value of 0.55 W⸱m −1 ⸱K −1 at 673 K in x = 0.10 sample. Ultimately, a zT value of 0.53 at 673 K is attained in x = 0.10 sample. The modification of bonding environment around anion is considered as an effective mean to optimize the thermoelectric performance of quaternary chalcogenides.
研究领域:
材料科学
·
凝聚态物理
·
功能材料
·
热电转换
·
固态化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Simin Gu,Mao Xia,Cheng Zhou,Zihui Kong,Maxim S. Molokeev,Li Liu,Wai-Yeung Wong,Zhi Zhou
The discovery of novel Mn 4+ -doped oxide red phosphor with suitable spectrum for plant growth is a hot issue in the recent years due to the characteristic red photoluminescence of 2 E g → 4 A 2 transition in Mn 4+ ions. Generally, the emission position of Mn 4+ is hard to tune because of specific crystal field in most phosphors. In this work, tunable luminescence property with obvious red shift in the spectra is observed in the Mn 4+ -doped SrMgAl 10-y Ga y O 17 red phosphor via simple substitution of Ga 3+ for Al 3+ , and crystal field theory and nephelauxetic effect are employed to explain this phenomenon. Meanwhile, the Ga 3+ dopant changes the shape of the spectra because Ga 3+ dopant guides the replacement site of Mn 4+ and changes the luminescence center. Improved emission intensity is obtained because appropriate Ga 3+ doping leads to larger band gap and reduces non-radiative transitions. Phosphor-converted LED (pc-LED) devices fabricated with blue chip (470 nm) and the as-obtained SrMgAl 10-y Ga y O 17 :1.0%Mn 4+ phosphors emit bright blue and red light, which fit the absorption regions of plant pigments well, thus SrMgAl 10-y Ga y O 17 :Mn 4+ phosphor can be a candidate for plant growth LED light.
研究领域:
材料科学
·
光电子学
·
固体化学
·
农业光生物学
·
发光材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 16
·13925-13930
·
IF 2.324
Li Tianjing,Shi Qingle
In this paper, explain a new relationships between Bi 3+ content, the phase crystal, microstructure and conductivity for Sm and Bi co-doped Ce 0.8− x Sm 0.2 Bi x O 1.9−1/2 x ( x = 0, 0.05, 0.1, 0.15, 0.2) electrolytes prepared by co-precipitation method. The XRD patterns showed that this compounds exhibit a fluorite-type cubic structure after the samples calcined at 700 °C for 4 h and the cell volumes of increased when the Bi content increased. In addition, for the samples sintered at 1400 °C for 4 h, the Bi doping improves the relative density, the grain size and the average thermal expansion coefficient (TEC). More in details, the relative density and TEC increase with the Bi content. Form the AC impedance spectroscopy measurements, the conductivity of the sintered samples is found to improve with the increasing of Bi content (for x ≤ 0.15), which is ascribed to the increasing of the number of oxygen ion vacancies and the increase in the unit cell volume. However, the conductivity decreases when the Bi content is further increased (0.15 < x ≤ 0.2), which is ascribed the reduction of the number of free oxygen vacancies. The highest conductivity at 800 °C is 5.6 × 10 −2 S/cm and the activation energy is 0.83 eV for Ce 0.65 Sm 0.2 Bi 0.15 O 1.825 , indicating that this would be a promising electrolyte for the intermediate temperature-solid oxide fuel cell applications.
研究领域:
材料科学
·
无机非金属材料
·
固态离子学
·
能源材料
·
燃料电池
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 49
·期 23
·39700-39706
·
IF 5.2
Xinkun Liu,Ying Dai,Xinmei Pei,Wen Chen
Ferroelectric thin films with giant room-temperature electrocaloric effect (ECE) could be very useful in design of solid-state refrigeration devices. Here, lead-free Ba 0.85 Ca 0.15-x Sr x Zr 0.1 Ti 0.9 O 3 (BCZT-xSr, 0.01 ≤ x ≤ 0.10) thin films are successfully prepared on the substrates (Pt/Ti/SiO 2 /Si) via sol-gel route, and the effect of the Sr substitution on the structure, electric properties and ECE of the films were investigated. The dielectric analyses show that the rhombohedral-tetragonal phase transition temperature (T R-T ) move to a higher temperature and the tetragonal-cubic phase transition temperature (T m ) shift to a lower temperature with increasing Sr content, and finally the T R-T peaks merge into the T m peaks at room temperature. The BCZT-0.05Sr film presents a giant ECE with ΔT = 27.1 K and ΔS = 30.6 J K −1 kg −1 at 800 kV cm -1 near room temperature (301 K). The giant ΔT benefits from a multiphase coexisting region with successive R-T and T-C phase transition character near room temperature. These results indicate that the lead-free Sr-doped BCZT thin film is an attractive material for application in ECE refrigeration devices.
研究领域:
材料科学
·
凝聚态物理
·
功能材料
·
热电转换
·
固态制冷
✓ 已验证
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2019
·
IF 3.834
Nan Zhou,Peixing Gao,Yimei Yang,Yuan Zhong,Mao Xia,Ye Zhang,Yun Tian,Xiangyang Lu,Zhi Zhou
In this paper, a series of novel orange-red emission phosphors Sr 8 ZnY(PO 4 ) 7 :Sm 3+ (SZYP:Sm 3+ ) were synthesized by high-temperature solid-state reaction. The photoluminescence and concentration-dependent properties of this phosphor were investigated carefully through diffuse reflection spectra, excitation and emission spectra, Commission Internationale de l'Éclairage (CIE) chromaticity coordinate and decay times. SZYP:Sm 3+ could be efficiently excited by n-UV and blue lights which center at 318, 345, 363, 376, 401, 410, 440 and 475 nm, respectively. The characteristic orange-red emission peaking at 563, 601 and 647 nm had been detected, which should be attributed to the characteristic f – f forbidden transition of Sm 3+ . The internal quantum efficiency (IQE) of ideal phosphor of SZYP:0.09Sm 3+ reached as high as 47%. In addition, The concentration quenching mechanism and thermal stability of SZYP:Sm 3+ were further investigated. It was found SZYP:Sm 3+ can maintain 93% of initial emission intensity at 150 °C and the corresponding activation energy was calculated to be 0.26 eV based on Arrhenius formula. The emission intensity of 1.0Mg 2+ and 0.02Al 3+ incorporated SZYP:0.09Sm 3+ reached up to 134% and 117% of the initial value, respectively. Moreover, (light-emitting diodes) LED devices were fabricated by employing the optimized samples as orange-red component with 365 nm n-UV chips. The desired emission in plant absorption region and extremely high thermal stability imply that SZYP:Sm 3+ is suitable for the application in plant growth LED lighting.
研究领域:
材料科学
·
光学工程
·
固体化学
·
光电子学
·
农业照明技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 76
·48238-48244
·
IF 3.108
Jiangyun Dai,Chao Yang,Hong Zhang,Hua Zhang,Guoying Feng,Shouhuan Zhou
The successful synthesis of rare earth doped nano/microcrystals with the desired morphology, uniform monodispersity, and intense infrared emission is of fundamental significance, and would facilitate their application in infrared emission-related miniaturization and integration in optoelectronics. However, simultaneously controlling the morphology and enhancing the infrared emission through simple and effective methods has not been well explored. In this study, via Ca2+ doping with an optimized concentration of 25 mol% in the hydrothermal solution, irregular NaGdF4:Yb/Er submicrocrystals converted into highly uniform submicrorods. Meanwhile, an obvious enhancement of visible upconversion (UC) and near-infrared (NIR) downconversion (DC) emission were obtained, probably due to the improved morphology and lowering the local crystal field symmetry around the rare earth ions induced by Ca2+ doping. Furthermore, Ce3+ ions with an optimized concentration of 2 mol% were codoped to intentionally tailor the branching ratio through efficient energy transfer from Er3+ to Ce3+. As a result, the ∼1530 nm emission intensity of the NaGdF4: 25Ca/2Ce/20Yb/2Er submicrorods increased by about 6.4 times in comparison with the NaGdF4:20Yb/2Er counterpart.
研究领域:
材料科学
·
光学工程
·
纳米技术
·
稀土化学
·
光电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2020
·
IF 8.247
Donghao Wang,Yuqi Wu,Xuefan Zheng,Shijun Tang,Zhengliang Gong,Yong Yang
All-solid-state Li–S batteries (ASSLSBs) offer an opportunity to realize both high energy density , safety and reliability, via eliminating the polysulfides shuttle effect and flammable liquid electrolyte. However, the sluggish kinetics of S and Li 2 S solid conversion results in low discharge capacity at high active material loading, which is critical for ASSLSBs to implement the high energy density potential. Herein, nitrogen doped-carbon (NC) coated Li 2 S (Li 2 S@NC composite) is developed for ASSLSBs that highly improves electrochemical performance. A thin and uniform nitrogen doped-carbon layer is coated on Li 2 S via pyrolysis deposition approach to prepare Li 2 S@NC. The as obtained Li 2 S@NC composite exhibits greatly enhanced electrochemical performance with high reversible capacity, high coulombic efficiency of ~100%, good rate capability and cycling stability. Particularly, outstanding electrochemical performance with high capacity of 931 mAh g −1 can also be obtained at both high Li 2 S content (43%) and high areal Li 2 S loading (10.4 mg cm −2 ).
研究领域:
材料科学
·
电化学
·
能源存储
·
固态电池
·
纳米材料
✓ 已验证
DOI
高影响因子
Laser & Photonics Reviews
·
2023
·Vol. 18
·期 1
·2300717
·
IF 11
Yuzhen Wang,Gaochao Liu,Zhiguo Xia
Near-infrared (NIR) II region (1000–1700 nm) lighting sources possess special potential for temperature sensing and quantitative composition analysis. However, it is a challenge to tune the luminescence toward such long wavelength NIR-II emission. Herein, Cr 4+ ions occupation is designed and verified in olivine-type CaYGaO 4 as [CrO 4 ] tetrahedron by site occupancy confinement. Under 620 nm red light excitation, the phosphors display broadband NIR-II emission centered at 1330 nm with a full width at half maximum (FWHM) of 233 nm, resulting from spin-allowed 3 T 2 to 3 A 2 transition of Cr 4+ ions in T d symmetry. The optical thermometry application is demonstrated by decoding the spectral shift and decay times varying with temperature, and the maximum relative sensitivities are 5.82% and 0.78% K −1 , respectively. Furthermore, a flexible film containing CaYGaO 4 :Cr 4+ is fabricated to implement the non-invasive detections of fillet temperature and NH 3 concentration in ammonia. This work represents a step toward developing next-generation NIR-II luminescence materials and widens non-invasive detection applications.
研究领域:
材料科学
·
光学工程
·
生物医学工程
·
无创检测技术
·
分子成像
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）