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
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
Russian Journal of Physical Chemistry A
·
2024
·Vol. 97
·期 14
·3227-3237
·
IF 0.7
Zheng Yayuan
This paper investigates the kinetics of sodium sulfate crystallization in a stirred bed crystallizer through experimental analysis, focusing on the homogeneous and heterogeneous nucleation mechanisms of the compound. Key nucleation parameters, including tension (γ), critical nucleation radius ( r* ), critical nucleation free energy (Δ G* ), and critical nucleation molecule number ( i* ), are measured under various temperatures and supersaturation ratios, utilizing classical nucleation theory. The results demonstrate that as temperature and supersaturation ratio increase, induction time, critical nucleation free energy, critical nucleation radius, and critical molecule number decrease, while nucleation rate increases. The crystal shape remains relatively constant with changes in temperature and supersaturation ratio, but the average particle size increases with higher supersaturation and temperature. The observed changes in nucleation parameters are consistent with classical nucleation theory. In addition, population balance equations are employed to fit kinetic equations for crystal nucleation and growth rates in a stirred crystallization system. The results show that the growth rate increases with higher supersaturation and stirring rates, while the influence of parameters in the nucleation rate equation suggests that suspension density has the greatest effect, followed by supersaturation ratio and stirring rate.
研究领域:
化学工程
·
材料科学
·
物理化学
·
过程工程
·
晶体工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·Vol. 43
·期 3
·2969-2973
·
IF 2.758
Bing Xie,Haibo Zhang,Hao Kan,Sisi Liu,Ming-Yu Li,Zeyu Li,Shuai Zhu,Shiyong Qiu,Shenglin Jiang
This work demonstrates a highly efficient method for large-scale synthesis of elongated BaTiO 3 nanowires via a novel stirring hydrothermal process. Compared with conventional hydrothermal reaction , one-dimensional (1D) lead-free BaTiO 3 nanowires can be realized at an even lower temperature with a shorter dwelling time. Results suggest that the mechanical force-driven stirring process improved the diffusion and surface reaction rate of BaTiO 3 nanocrystal growth in the solution phase, apparently, leading to the growth of the BaTiO 3 nanowires via an oriented attachment mechanism. Meanwhile, to the best of our knowledge, this method is also the first reported protocol which is capable to grow elongated BaTiO 3 nanowires with length up to tens of micrometers. This research outcome provides a promising option for low cost, high-throughput fabrication of 1D nanostructure in respect of mass-manufacturing.
研究领域:
材料科学
·
纳米科技
·
无机合成
·
功能材料
·
铁电材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Lei Meng,Bin Yao,Yongfeng Li,Zhanhui Ding,Zhenyu Xiao,Kaisi Liu,Gang Wang
The back contact adhesion is the important factor of the microstructural performance which can determine the optoelectronic properties of the kesterite-based solar cells. Here, we present a rational and effective strategy to significantly enhance the back contact adhesion of Cu 2 (Zn,Cd)Sn(S,Se) 4 (CZCTSSe) absorber layers by insetting the appropriate thickness carbon-doping CZCTS thin films . We chose the oleylamine as the carbon-doping reagent which can generate a small amount of carbon in the annealing process . The suitable thickness carbon-doping CZCTS films can significantly change the crystal growth mechanism of CZCTSSe absorber layers, and eliminate the holes in the back contact. The efficiency of CZCTSSe solar cells fabricated by insetting the appropriate thickness carbon-doping CZCTS films is above 7%, and shows the excellent repeatability and long-term air stability compared with the control devices.
研究领域:
材料科学
·
光伏技术
·
半导体物理
·
表面与界面工程
·
无机功能材料
✓ 已验证
DOI
高影响因子
POLYHEDRON
·
2016
·
IF 2.108
Tongguang Sun,Fei Liang,Xinyuan Zhang,Heng Tu,Zheshuai Lin,Guochun Zhang,Yicheng Wu
Single crystals of three new organic–inorganic hybrid compounds, tri[1-(diaminomethylene)uronium] hexachlorobismuthate ((C 2 H 7 N 4 S) 3 BiCl 6 ·H 2 O, HATU-BCH), bis[1-(diaminomethylene)uronium] pentabromobismuthate, ((C 2 H 7 N 4 S) 2 BiBr 5 , HATU-BB), and bis [3,5-diamino-1,2,4-thiadiazol-2-ium] pentaiodobismuthate ((C 2 H 5 N 4 S) 2 BiI 5 , OHATU-BI), have been successfully grown by slow evaporation method. Their structures were determined by single - crystal X-ray diffraction, in which all anion sublattice structures consist of hexahalobismuthates octahedra with different connection modes involving isolated, shared-corner, and shared-edge. The spectra characters were studied by Infrared and Raman spectra, which interpreted by calculation of the density functional theory (DFT) method and diffuse reflectance spectra. Thermal properties were characterized by thermal gravimetric analysis and differential scanning calorimetry.
研究领域:
材料化学
·
晶体工程
·
配位化学
·
光谱学
·
热分析
·
计算化学
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Xue Zou,Mucong Zi,Tiantian Wu,Yuanxin Yao,Caifeng Yang,Daoyi Chen
Kinetic hydrate inhibitors (KHIs) have gradually gained more attention in the natural gas and oil transportation field due to their remarkable inhibition performance at low dosages. However, the inhibition performance of most commercial KHIs is poor under high subcooling conditions. In this work, a radical polymerization method was used to synthesize four new KHIs by introducing the 1-vinylimidazole (VI) or vinylacetate (VAc) monomer. These newly-synthesized copolymer KHIs were characterized by Fourier Transform Infrared, 1 H nuclear magnetic resonance, and gel permeation chromatography, respectively. The cloud point of HY-201 is remarkably as high as 92.3 °C and the four KHIs are all biodegradable. Under subcooling of 10 K and 15 K, the inhibitory performance of four new KHIs and three commercial KHIs on hydrate nucleation and growth are as follows: PVP < Luvicap EG < Inhibex 501 < HY-101 < HY-201 < HY-301 < HY-401. In addition, the hydrate volume fraction of the four new KHIs at the optimal concentration of 15 K subcooling for 12 h was 13.3 %, 1.7 %, 2.4 %, and 2.1 %, respectively, which did not exceed 1/3 of the tested commercial KHIs. Further, the novel mechanism hypothesis is proposed as follows: the surface charge of the hydrate nuclei is neutralized by KHIs, and the hydrate nuclei aggregates, hindering the gas from entering the hydrate. In addition, the strong entanglement and adsorption of KHIs molecules with better inhibition performance make the hydrate lose the space for growth and expansion. Overall results highlight the great application prospects of these new KHIs in natural gas transmission based on the remarkable inhibition performance under high subcooling conditions.
研究领域:
石油与天然气工程
·
化学工程
·
材料科学
·
环境友好材料
·
流体输送
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wei Zhou,Wanglong Mao,Pingyang Huang,Xiong Huang,Haoyuan Xu,Bo Wu,Xiaofang Jiang,Xiangtao Chen,Hanyu Liu,Guofu Zhou,Jinyou Xu
This study introduces a facile method for the controlled growth of addressable planar arrays of highly luminescent, catalyst-free 1,4-bis(5-phenyloxazol-2-yl)benzene (POPOP) nanowires. By employing a hollow mask over a faceted sapphire substrate, simultaneous control over the position and orientation of the nanowires is achieved through a mask-confined graphoepitaxial growth, offering substantial advantages over traditional post-growth assembly techniques. High-temperature annealing creates parallel nanogrooves on the sapphire surface, inducing a graphoepitaxial effect that aligns the nanowires with a consistent [102] crystallographic axis. The hollow mask further aids in precisely localizing nanowire growth through its shadowing effect. Optoelectronic investigations reveal that these nanowires emit intense and stable blue photoluminescence at room temperature, with a broad spectrum spanning from 400 to 600 nm. This luminescence is achieved through excitation by continuous-wave ultraviolet light or two-photon absorption using femtosecond infrared light. Notably, the emission quantum efficiency of POPOP nanowires reaches 59 %, a remarkable improvement over the 12 % observed in powder counterparts when excited with 405 nm light. Transit absorption spectra indicate that ground state bleaching and excited state absorption display consistent kinetics within a 100 ps time window, suggesting the same origin from singlet excitons. The precise alignment and positioning of these nanowires make them viable for in-situ integration into photodetectors with rapid ultraviolet light responses. This study advances the controlled growth of catalyst-free nanowire arrays and enhances the understanding of the optoelectronic properties of POPOP nanowires.
研究领域:
材料科学
·
纳米科技
·
光电子学
·
凝聚态物理
·
表面科学
·
有机半导体
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Deshan Cheng,Mantang He,Wenbin Li,Jihong Wu,Jianhua Ran,Guangming Cai,Xin Wang
Growing of ZnO nanoparticles on PET films without crystal seeding has been achieved by employing polydopamine as the anchor. The PDA layer was formed on the surface of PET film by the polymerization of dopamine. The PDA-PET was dipped into zinc precursors for hydrothermal growth of ZnO nanoparticles. Cluster-like ZnO nanoparticles were obtained and the special structure was affected by the growing time and zinc ion concentration. The surface morphology, structure and properties were characterized, and the functions including antimicrobial activity and UV protection of the ZnO-coated PET film were investigated. The developed facile hydrothermal approach without seeding will benefit the development of UV resistant and antimicrobial PET films.
研究领域:
材料科学
·
纳米技术
·
表面功能化
·
生物医用材料
·
高分子材料
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Jiajie Yu,Muzhong Shen,Siyu Liu,Feng Li,Dongping Sun,Tianhe Wang
In this paper, we describe a simple technique for direct growth of gold nanoparticles (GNPs) into a nanostructured porous alumina layer on conductive glass slide (PAOCG). PAOCG was attached firmly with a small piece of steel and was then immersed in a HAuCl 4 solution. Electro-induced electrons from steel were employed to reduce AuCl 4 − on PAOCG. The galvanic replacement reaction (GRR) was adopted as the fundamental mechanism for reducing metal precursors. This mechanism was further studied by open circuit potential-time (OCP-t) experiment and the result demonstrated that steel induced the continuous proceeding of this reaction. This strategy presents a simple and general protocol for preparation of metal nanoparticles (MNPs) on conductive glass substrates. The SERS properties of Au/PAOCG were investigated using aqueous crystal violet (CV) and 4-mercaptopyridine (4-Mpy) as probe molecules. Au/PAOCG allowed as low as 10 −9 M CV and 10 −8 M 4-Mpy to be detected. The reusability of this substrate was achieved by measuring the SERS spectrum of the probe molecules followed with a 400 °C heat treatment for 10 min to remove the residuals. This substrate could be reused for at least ten cycles without any significantly reduced SERS performance. Therefore, this surface can serve as a portable, durable and reusable SERS substrate and has a potential for commercial applications.
研究领域:
材料科学
·
分析化学
·
纳米技术
·
生物传感
·
表面科学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 36
·16907-16918
·
IF 6.97
Hong Lin,Jian Mao,Minchao Qin,Zhilong Song,Wanjian Yin,Xinhui Lu,Wallace C. H. Choy
While red is one of the primary colors for display applications, the investigation of visible red emitting perovskites, particularly 2D perovskites, is relatively limited. In this work, we demonstrate a single-phase Ruddlesden–Popper quasi-2D (C3H7NH3)2CsPb2I7 perovskite for red color LEDs. Through increasing the annealing temperature of (C3H7NH3)2CsPb2I7 perovskite thin films, we have successfully achieved tunable emission wavelengths from 654 to 691 nm. Equally important, for all the quasi-2D perovskite LEDs, once the annealing temperature is fixed, the emission spectrum is independent of bias voltages, which is very important for their use in lighting and displays. With the analysis of the crystallinity, morphology, and thermodynamic stability of the quasi-2D perovskite, we find that the obtained (C3H7NH3)2CsPb2I7 perovskite is a single-phase quasi-2D perovskite with only n = 2 phase. Besides, we found that the red shifting of emission wavelength is caused by the increase of perovskite crystal size while increasing the annealing temperature. Our results also show that the temperature-induced color tunability can be applied to a series of quasi-2D perovskites with different alkylammonium cations. Importantly, we find that short alkylammonium spacers offer better electrical properties for efficient current transport and high performance in LED applications. This work contributes to controlling the optoelectronic properties of quasi-2D perovskites via controlling their crystal growth as well as paves the way to realize practical lighting and display applications of perovskite LEDs.
研究领域:
材料科学
·
光电功能材料
·
半导体器件
·
纳米结构材料
·
固态照明
✓ 已验证
DOI
高影响因子
Advanced Electronic Materials
·
2021
·Vol. 8
·期 4
·2101125
·
IF 7.295
Qi-Qi Wang,Fan Li,Sheng-Qing Xia,Jian Liu,Xiao-Cun Liu,Ling Chen,Cheng-Qian Zhang
The single crystal growth of Mg 3 Bi 2 -based thermoelectric materials is of great significance for their applications near room temperature. So far, it is still a big challenge to grow such bulk single crystals and attempts are primarily focused on the metal flux methods. For the first time, bulk single crystals of n-type Mg 3 Bi 1.49 Sb 0.5 Te 0.01 are directly grown by applying an In-situ Loading Bridgman method. The as-grown single crystal features an excellent carrier mobility of 220 cm 2 V −1 s −1 , which is among the best compared to other Mg 3 Bi 2 -based bulk materials. Besides, this method is successfully developed to fast grow uniform polycrystalline materials with high thermoelectric and mechanic performance. As demonstrated by the single-leg device, a large temperature difference of 10.5 K is achieved at the supplied electric current of 0.6 A, much superior to other room temperature state-of-the-art thermoelectric materials. With the single crystalline and polycrystalline materials prepared reliably and conveniently, in-depth investigations on the Mg 3 Bi 2 thermoelectric system can be greatly benefited, which should as well significantly facilitate their practical applications at room temperature.
研究领域:
材料科学
·
热电学
·
凝聚态物理
·
晶体生长
·
功能材料
·
能源材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）