JOURNAL OF CRYSTAL GROWTH
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2012
·
IF 1.726
Shenjie Li,Daocheng Pan
Cu 2 SnSe 3 nanocrystals with a metastable zincblende and wurtzite structure have been successfully synthesized. The crystal structures were confirmed by means of X-ray diffraction and selected area electron diffraction . The lattice mismatch between Cu 2 SnSe 3 and ZnSe is only 0.26%, thus homogeneously alloyed (ZnSe) x (Cu 2 SnSe 3 ) 1− x nanocrystals could be synthesized. The band gaps of nanocrystals can be tuned in a wide range of 2.75 to 0.92 eV; however the bowing parameter as high as 19.1 eV for alloyed (ZnSe) x (Cu 2 SnSe 3 ) 1− x nanocrystals was observed. These low cost and dispersible alloyed (ZnSe) x (Cu 2 SnSe 3 ) 1− x nanocrystals with a targeted band gap have a high potential in thin film solar cells.
研究领域:
材料科学
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太阳能电池研究
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DOI
高影响因子
NATURE MATERIALS
·
2020
·Vol. 19
·期 5
·528-533
·
IF 38.663
Zeng Mengqi,Liu Jinxin,Zhou Lu,Mendes Rafael G.,Dong Yongqi,Zhang Min-Ye,Cui Zhi-Hao,Cai Zhonghou,Zhang Zhan,Zhu Daming,Yang Tieying,Li Xiaolong,Wang Jianqiang,Zhao Liang,Chen Guoxian,Jiang Hong,Rümmeli Mark H.,Zhou Hua,Fu Lei
Developing a precise and reproducible bandgap tuning method that enables tailored design of materials is of crucial importance for optoelectronic devices. Towards this end, we report a sphere diameter engineering (SDE) technique to manipulate the bandgap of two-dimensional (2D) materials. A one-to-one correspondence with an ideal linear working curve is established between the bandgap of MoS 2 and the sphere diameter in a continuous range as large as 360 meV. Fully uniform bandgap tuning of all the as-grown MoS 2 crystals is realized due to the isotropic characteristic of the sphere. More intriguingly, both a decrease and an increase of the bandgap can be achieved by constructing a positive or negative curvature. By fusing individual spheres in the melted state, post-synthesis bandgap adjustment of the supported 2D materials can be realized. This SDE technique, showing good precision, uniformity and reproducibility with high efficiency, may further accelerate the potential applications of 2D materials.
研究领域:
材料科学
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光电子学
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纳米技术
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DOI
PubMed
高影响因子
Nature Communications
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2020
·Vol. 11
·期 1
·1-13
·
IF 12.121
Zhao Fulai,Feng Yiyu,Wang Yu,Zhang Xin,Liang Xuejing,Li Zhen,Zhang Fei,Wang Tuo,Gong Jinlong,Feng Wei
The discovery of graphene and graphene-like two-dimensional materials has brought fresh vitality to the field of photocatalysis. Bandgap engineering has always been an effective way to make semiconductors more suitable for specific applications such as photocatalysis and optoelectronics. Achieving control over the bandgap helps to improve the light absorption capacity of the semiconductor materials, thereby improving the photocatalytic performance. This work reports two-dimensional −H/−OH terminal-substituted siligenes (gersiloxenes) with tunable bandgap. All gersiloxenes are direct-gap semiconductors and have wide range of light absorption and suitable band positions for light driven water reduction into H 2 , and CO 2 reduction to CO under mild conditions. The gersiloxene with the best performance can provide a maximum CO production of 6.91 mmol g −1 h −1 , and a high apparent quantum efficiency (AQE) of 5.95% at 420 nm. This work may open up new insights into the discovery, research and application of new two-dimensional materials in photocatalysis.
研究领域:
材料科学
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光催化
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半导体物理
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能源材料
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DOI
高影响因子
Nanoscience and Nanotechnology Letters
·
2015
·Vol. 7
·期 5
·398-401
·
IF 1.431
Wang Shanshan,Zhang Jun,Peng Feng,Shao Lexi
Micron-sized Cu2FeSnS4 single crystals were synthesized by molten salt method using CuS, FeS and SnS as raw materials and using CsCl as fluxing agent for the first time. The Cu2FeSnS4 single crystals were investigated by X-ray diffraction,
Raman, X-ray photoelectron spectroscopy and UV-vis absorbance spectroscopy. The results showed that the Cu2FeSnS4 single crystals were having stannite structure with an average size about 50–100 μm and the band gap was about 1.45 eV.
研究领域:
材料科学
·
化学
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DOI
高影响因子
INORGANIC CHEMISTRY
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2012
·
IF 4.601
Wenlong Yin,Wendong Wang,Lei Bai,Kai Feng,Youguo Shi,Wenyu Hao,Jiyong Yao,Yicheng Wu
The 12 new rare-earth tellurides Ba2MLnTe5 (M = Ga and Ln = Sm, Gd, Dy, Er, Y; M = In and Ln = Ce, Nd, Sm, Gd, Dy, Er, Y) have been synthesized by solid-state reactions. The two compounds Ba2GaLnTe5 (Ln = Sm, Gd) are isostructural and crystallize in the centrosymmetric space group P1̅, while the other 10 compounds belong to another structure type in the noncentrosymmetric space group Cmc21. In both structure types, there are one-dimensional anionic 1∞[MLnTe5]4– chains built from LnTe6 octahedra and MTe4 (M = Ga, In) tetrahedra, but the connectivity between the LnTe6 octahedra and MTe4 tetrahedra is different for the two structure types. On the basis of the diffuse-reflectance spectra, the band gaps are around 1.1–1.3 eV for these compounds. The Ba2MLnTe5 (M = Ga and Ln = Gd, Dy; M = In and Ln = Gd, Dy, Er) compounds are paramagnetic and obey the Curie–Weiss law, while the magnetic susceptibility of Ba2InSmTe5 deviates from the Curie–Weiss law. In addition, electronic structure calculation on Ba2MYTe5 (M = Ga, In) indicates that they are both direct-gap semiconductors with large nonlinear-optical coefficients.
研究领域:
材料科学
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凝聚态物理
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DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2013
·Vol. 15
·期 47
·20698-20705
·
IF 3.829
Dongfang Hou,Xianluo Hu,Yanwei Wen,Bin Shan,Pei Hu,Xiaoqin Xiong,Yun Qiao,Yunhui Huang
Sillenite Bi12MO20 (M = Ti, Ge, Si) nanofibers have been fabricated through a facile electrospinning route for photocatalytic applications. Uniform Bi12MO20 (M = Ti, Ge, Si) nanofibers with diameters of 100–200 nm and lengths of up to several millimeters can be readily obtained by thermally treating the electrospun precursors. The photocatalytic activities of these nanofibers for degradation of rhodamine B (RhB) were explored under UV-visible light. The band structure and the degradation mechanisms were also discussed. The fibrous photocatalysts of Bi12TiO20, Bi12SiO20 and Bi12GeO20 exhibit different photocatalytic behaviours, which are attributed to the microstructure, band gap, and electronic structures.
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Haihong Wang,Huiyan Ma,Yan Li,Lin Cheng,Jucai Yang,Juming Liu
Efficient, low-cost, and easily scalable wide-spectral-responsive TiO2 photocatalysts are still extremely desired in driving photocatalytic degradation toward practical applications. In this work, a modified TiO2 with a narrow band gap and low valence band (VB) (CC-OV-TiO2) was successfully synthesized based on a facile sol–gel and low-temperature carbonization process, which can be used for the photocatalytic degradation and mineralization of a wide range of phenols. The results show that the interstitial doping of carbonates and the modification of surface oxygen vacancy (OV) defects together contribute to the formation of the VB tail states, which substantially narrow the band gap of TiO2 and widen the photoresponse range. Meanwhile, the carboxylated carbon species induce a substantial downward shift of the VB edge through coordination of the electron-withdrawing carboxyl groups, which further enhances the oxidation ability of the photogenerated holes. Accordingly, CC-OV-TiO2 with a narrow band gap and low VB exhibits superior and stable photocatalytic performance.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·
IF 5.7
Ruijing Fu,Junpeng Gao,Pinsen Zhang,Lingrui Wang,Bo Wang,Guangxia Wang,Xiaoshuang Li,Youchao Kong,Qingguang Zeng,Guanjun Xiao
Manganese (Mn)-based organic–inorganic metal halides (OIMHs) are extensively employed in various optical applications due to their non-toxicity, superior optical properties, and tunable emission advantages. Developing effective strategies to enhance the optical properties of these materials and clarifying their structure–optical property relationships continue to be of significant interest. Here, we report that the zero-dimensional (0D) (C24H20P)2MnBr4 exhibits remarkable pressure emission tuning that shifts from green to red, a phenomenon driven by the enhancement of the crystal field splitting energy and the reduced energy difference of the lowest d–d transition (4T1 → 6A1) motivated by the shortening of Mn–Br bonds. Additionally, the band gap value of (C24H20P)2MnBr4 becomes 3.13 eV, showing an unexpected decrease by 1.09 eV from an initial value of 4.22 eV, when the pressure is released from 31.0 GPa. The incomplete recovery of the distortion in [MnBr4]2− tetrahedra, impeded by the distortion of soft organic macromolecules, is believed to be responsible for band gap narrowing. Combined with computations and subsequent experiments, it is inferred that pressure induced reduction in the Mn–Br bond distance contributes to the distortion of tetrahedral [MnBr4]2− and larger-sized organic cations. Our work not only elucidates the structure–optical property relationships in Mn-based OIMHs, but also opens new avenues for modulating their optical properties and devising innovative strategies for designing novel Mn-based OIMHs.
研究领域:
材料科学
·
光学
·
化学
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DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2023
·
IF 2.8
Yajie Wang,Xiaoyan Gan,Wei Zheng,Liling Guo,Hanxing Liu
Halide double perovskite Cs 2 AgBiBr 6 hinders its wide range of optoelectronic applications due to large band gap. This work focuses on Sb 3+ /In 3+ doping to tune the band gap of Cs 2 AgBiBr 6 thin films. The influences of annealing temperature and doping amount of Cs 2 Ag(B x Bi 1-x )Br 6 (B = Sb 3+ , In 3+ ) thin films were investigated. When annealed at the optimized temperature of 150 °C, the Cs 2 Ag(B x Bi 1-x )Br 6 (B = Sb 3+ , In 3+ ) thin films accommodate up to 100% Sb 3+ and 70% In 3+ , respectively, without showing any secondary phases. The band gap of Cs 2 Ag(B x Bi 1-x )Br 6 (B = Sb 3+ , In 3+ ) thin films decreases as the increase of Sb 3+ and increases as the increase of In 3+ amount. Therefore, the band gap regulation of 0.39 eV is realized, with the smallest value of 2.25 eV for Cs 2 AgSbBr 6 and highest value of 2.64 eV for Cs 2 Ag 0.3 In 0.7 Br 6 , respectively. Our work confirms an approach to realize band gap adjustment of Cs 2 AgBiBr 6 thin films.
研究领域:
材料科学
·
光电子学
·
半导体物理
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DOI
高影响因子
Journal of Physical Chemistry C
·
2017
·
IF 4.536
Zhan Zhang,Lixia Ren,Hong Yan,Shujin Guo,Shuanhu Wang,Min Wang,Kexin Jin
Single crystals of heterovalent Bi-doped CH3NH3PbCl3 perovskite have been successfully grown through the inverse temperature crystallization method. Bandgap narrowing of 300 meV (a 55 nm red-shifting absorption edge) is obtained for the nominal 20% Bi-doped crystal with the host structure and the energy at the top of the valence band invariable. It is observed that the contact between the Au electrodes and single crystals transforms from Ohmic to Schottky, and the conductivity increases with increasing Bi doping level. By contrast, the Bi-doped CH3NH3PbCl3 thin films are also prepared, and the similar bandgap narrowing is found, although the narrowing degree is less than that in single crystals. This work has a comprehensive understanding of Bi-doped single crystals and thin films, providing further optoelectronic applications for these promising solution-processed hybrid perovskite semiconductor materials.
研究领域:
材料科学
·
光学
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DOI
高影响因子
Catalysis Science & Technology
·
2017
·Vol. 7
·期 4
·982-987
·
IF 5.773
Zongwei Mei,Mingjian Zhang,Julian Schneider,Wei Wang,Ning Zhang,Yantao Su,Bingkun Chen,Shufeng Wang,Andrey L. Rogach,Feng Pan
A series of hexagonal Zn1−xCdxS photocatalysts with variable composition (0.2 ≤ x ≤ 1) is synthesized by a solvothermal method. XPS spectra of Zn 2p and Cd 3d regularly shift upon changing the composition of Zn1−xCdxS samples, due to the difference in the Mulliken atomic charges of Zn, Cd, and S. The photocatalytic activity of the samples for H2 evolution from water was tested under visible-light irradiation (λ ≥ 420 nm) without a cocatalyst; the Zn0.4Cd0.6S sample exhibited the highest photocatalytic H2 evolution rate, which was about 81 mL h−1 g−1. Under irradiation with a 368 nm LED, the H2 evolution rate decreased with increasing Cd fraction in the Zn1−xCdxS solid solution. By comparing the crystallinity, surface area, valence/conduction band positions, absorption spectra and fluorescence lifetimes, we conclude that the photocatalytic activity is related to the balance between the absolute positions of the valence/conduction bands and light absorption ability of the Zn1−xCdxS photocatalysts.
研究领域:
材料科学
·
能源化学
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DOI
高影响因子
Journal of Energy Chemistry
·
2016
·
IF 2.322
Xin Liu,Junzhe Jiang,Yushuai Jia,Ailing Jin,Xiangshu Chen,Fei Zhang,Hongxian Han
Pure phase, regular shape and well crystallized nanorods of p-type semiconductor CaFe 2 O 4 have been fabricated for the first time by a facile molten salt assisted method, as confirmed by XRD , TEM, SEM and HRTEM. UV−vis diffuse reflectance spectra and Mott–Schottky plots show that the band structure of the CaFe 2 O 4 nanorods is narrower than that of the CaFe 2 O 4 nanoparticles synthesized by conventional method. The enhancement of the visible-light absorption is due to narrowness of the band gap in CaFe 2 O 4 nanorods. The appropriate ratio between the molten salt and the CaFe 2 O 4 precursors plays an important role in inhibiting the growth of the crystals along the (201) plane to give the desired nanorod morphology. This work not only demonstrates that highly pure p-type CaFe 2 O 4 semiconductor with tunable band structure and morphology could be obtained using the molten salt strategy, but also affirms that the bandgap of a semiconductor may be tunable by monitoring the growth of a particular crystal plane. Furthermore, the facile eutectic molten salt method developed in this work may be further extended to fabricate some other semiconductor nanomaterials with a diversity of morphologies.
研究领域:
材料科学
·
半导体物理
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产品关联
DOI
高影响因子