Applied Materials Today
·
2019
·
IF 8.013
Lei Tong,Xiaoyan Duan,Luyao Song,Tiande Liu,Lei Ye,Xinyu Huang,Peng Wang,Yuanhui Sun,Xin He,Lijun Zhang,Ke Xu,Weida Hu,Jian-Bin Xu,Jianfeng Zang,Gary J. Cheng
Intrinsic linear polarized optics discovered in anisotropic two-dimensional (2D) materials has attracted intense interest for polarization-sensitive optical and optoelectronic applications , such as black phosphorous, ReSe 2 , etc. However, the lack of matured method to synthesize high-quality, large-scale and air-stable 2D materials with anisotropic properties, is still an obstacle for practical applications. Monolayer molybdenum disulfide (MoS 2 ), which exhibits strong direct-band-gap light-harvesting properties, can be grown maturely. But unfortunately, MoS 2 does not show linear dichroism owing to its in-plane isotropic crystalline symmetry. We, herein, for the first time, report on an artificial control of extrinsic linear polarized photoelectric effect in monolayer MoS 2 , by successfully controlling its anisotropic degree of in-plane crystal symmetry via artificially induced uniaxial tensile strain . Strong linear polarization-sensitive photodetection from visible to near-infrared range is realized for monolayer MoS 2 -based device, and the polarization anisotropic ratio can reach up over 2.0 under 4.5% strain. The observation is supported by combination of experiment-theory study on polarized Raman spectrum and optical absorption under gradually applied strains. Our results have demonstrated that the artificial-controlled symmetry reducing of MoS 2 is a promising strategy to achieve high performance polarization photodetection. This method can also be extended to other 2D materials, which potentially opens up a new field to endow isotropic 2D materials with anisotropic functionalities by artificial structure engineering.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 11
·1-8
·
IF 5.479
Hu Xiaopeng,Xi Jiajia,Xia Yuanyuan,Zhao Faqiong,Zeng Baizhao
A space-confined synthesis method is employed for the preparation of a single-layer MoS 2 –boron doped ordered mesoporous carbon nanocomposite. A phenol-formaldehyde resin is used as carbon source to create a confined space for the formation of single-layer MoS 2 . The addition of pluronic F127, as a soft template, suppresses the stacking of MoS 2 layers and makes the composite porous. The nanocomposite is characterized by scanning electron and transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The single-layer MoS 2 sheets have a lateral size of about 5 nm and are uniformly embedded in the composite. They possess numerous active edge sites and display a strong synergistic effect with other components. The composite is modified on a glassy carbon electrode, followed by the electrochemical imprinting of theophylline, and the resulting electrode exhibits good electrochemical response to theophylline. The linear response range is 0.01–250 μM by differential pulse voltammetry, and the lower detection limit is 5 nM. It has been successfully applied to the determination of theophylline in spiked tea drink samples.
Single-layer MoS 2 –boron doped ordered mesoporous carbon nanocomposite has large surface area and high catalysis, when coupling with molecularly imprinted polymer the resulting electrode shows highly sensitive and selective response to theophylline.
研究领域:
材料科学
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分析化学
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药物分析
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产品关联
DOI
PubMed
高影响因子
Advanced Materials Interfaces
·
2022
·Vol. 9
·期 17
·2200383
·
IF 6.389
Chenxi Huang,Chen Chen,Wenyuan Wang,Jun Fu,Miaomiao Xiang,Yue Xing,Qi Chen,Hualing Zeng,Xiang Shao
The structure and morphology of the substrate surface play critical roles in tuning the properties of the supported two-dimension materials (2DM). In this work, a simple strategy to engineer the SrTiO 3 single crystal into a trenched structure which is composed of atomically flat terraces and high steps of several nanometers is developed. Through the conventional chemical vapor deposition method, high quality single-layered MoS 2 nanosheets are successfully fabricated directly on the trenched SrTiO 3 (Tr-STO) substrate, which thus result in a heterostructure with well-defined interface and controllable corrugated morphology. The corrugated MoS 2 /Tr-STO sample displays a drastically suppressed photoluminescence as compared to those grown on atomically flat substrates. Detailed scanning probe microscopy in combination with optical spectroscopy measurements demonstrates that the photoluminescence quenching occurs exclusively in the MoS 2 area carpeting the high SrTiO 3 steps, which can be attributed to the significantly reduced bandgaps hence massively enriched free charges in these regions. This work not only provides a new strategy to tailor the 2DM properties by simply engineering the substrate surface corrugations, but also brings deep insights into the dependence of properties of the hybridized system on the interface morphologies.
研究领域:
材料科学
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光学
·
表面科学
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产品关联
DOI
高影响因子
SOLID STATE COMMUNICATIONS
·
2016
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IF 1.458
Song Hao,Bingchu Yang,Jingye Yuan,Yongli Gao
Monolayer MoS 2 is an emerging two-dimensional semiconductor with wide-ranging potential applications in the next generation electronic and optoelectronic devices. Understanding the influences of the supporting substrates on the physical properties of grown MoS 2 is an important step toward its applications. Here we synthesized two typical rhomboid shaped MoS 2 on MoO 2 and triangle shaped MoS 2 on SiO 2 /Si substrates and characterized them by multiple means of X-Ray Photoemission Spectroscopy, Atomic Force Microscopy , Electrostatic Force Microscopy, Raman and Photoluminescence techniques. We found that triangle shaped MoS 2 exhibits different core level spectra compared with rhomboid shaped MoS 2 , attributed to dissimilar charge transfer with the underlying SiO 2 substrate. Interestingly, the triangle shaped MoS 2 single crystals exhibit distinct electrostatic and photoluminescence properties at center and edges. The underlying mechanism is proposed that partial decoupling of MoS 2 at edges from SiO 2 substrate induces different doping level and strain effects, resulting in anomalous physical properties at edges. The results reported here demonstrate that doping and strain effects induced by substrates have a significant influence on physical properties of monolayer triangle shaped MoS 2 ，which can be generally applicable to other transition metal dichalcogenides materials.
研究领域:
材料科学
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物理化学
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DOI
高影响因子
Nanoscale
·
2019
·Vol. 12
·期 3
·1958-1966
·
IF 6.97
Peng Yang,Yabing Shan,Jing Chen,Garel Ekoya,Jinkun Han,Zhi-Jun Qiu,Junjie Sun,Fei Chen,Haomin Wang,Wenzhong Bao,Laigui Hu,Rong-Jun Zhang,Ran Liu,Chunxiao Cong
Monolayer MoS2 is a direct bandgap semiconductor which is believed to be one of the most promising candidates for optoelectronic devices. Chemical vapor deposition (CVD) is the most popular method to synthesize monolayer MoS2 with a large area. However, many defects are always found in monolayer MoS2 grown by CVD, such as sulfur vacancies, which severely degrade the performance of devices. This work demonstrates a concise and effective method for direct growth of high quality monolayer MoS2 by using SiO2/Si substrates pretreated with sulfur vapor. The MoS2 monolayer obtained using this method shows about 20 times PL intensity enhancement and a much narrower PL peak width than that grown on untreated substrates. Detailed characterization studies reveal that MoS2 grown on sulfur vapor pretreated SiO2/Si substrates has a much lower density of sulfur vacancies. The synthesis of monolayer MoS2 with high optical quality and low defect concentration is critical for both fundamental physics studies and potential practical device applications in the atomically thin limit.
研究领域:
材料科学
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光学
·
半导体物理
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DOI
PubMed
高影响因子
ACS Nano
·
2019
·
IF 13.903
Huihui Liu,Yue Li,Miaomiao Xiang,Hualing Zeng,Xiang Shao
Interfacial charge transfer is critical for the photocatalytic activities of compositional photocatalysts. In this work, we have developed a strategy of growing single-layer MoS2 sheets on the rutile TiO2(110) single-crystal surface using a chemical vapor deposition method. Both on-site and off-site characterizations confirmed the monolayer thickness and single crystallinity of the MoS2 adlayer as well as the atomic flatness of the composite surface. Without the presence of contamination, the charge flow across the interface of MoS2 and TiO2 is greatly enhanced, which hence favors the charge separation under excitations and boots up the catalytic activity of the composite system. Moreover, we found the luminescing property of MoS2 is significantly tailored upon coupling with the TiO2 surface. Our work has established a method for revealing the interface properties of the transition-metal dichalcogenides and oxide semiconductors at the atomic level.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Miaomiao Xiang,Chenxi Huang,Yue Xing,Huihui Liu,Xiang Shao
Hybridization with oxide semiconductors provides a versatile strategy for tailoring physicochemical properties of two-dimensional materials (2DMs). However, the direct impacts of specific interface interactions have not yet been very well categorized, in particular at an atomic level. In the present work, through a chemical vapor deposition (CVD) method, we successfully grew monolayer MoS2 flakes on an atomically smooth rutile TiO2 single crystal with (100), (110), and (001) terminations. We found that the fabrication of comparable high-quality MoS2 on all of the TiO2 substrates can only be achieved via finely varying the growth parameters. Moreover, the photoluminescence of MoS2 also changes against the substrate terminations, showing a gradually reduced A0/A– exciton ratio following the sequence of (100) > (110) > (001). Detailed X-ray photoelectron spectroscopy measurements showed the same tendency for the binding energy shifts of both Ti and O in the MoS2/TiO2 samples, which were attributed to the varied dipole fields established at the MoS2/TiO2 interfaces. Our work not only reinforces the important role of interface charge redistribution in tailoring the properties of hybridized systems but also emphasizes that the facet effect may be applied as an efficient strategy for optimizing the photocatalytic activities of compositional systems.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
ACS Nano
·
2021
·
IF 15.881
Chenxi Huang,Jun Fu,Miaomiao Xiang,Jiefu Zhang,Hualing Zeng,Xiang Shao
The elaborate interface interactions can be critical in determining the achievable functionality of a semiconductor heterojunction (SH), particularly when two-dimensional material is enclosed in the system and its thickness is at an atomic extreme. In this work, we have successfully constructed a SH model system composed of typical transition-metal chalcogenide (TMDs) and transition metal oxides (TMO) by directly growing molybdenum sulfide (MoS2) nanosheets on atomically flat strontium titanate (SrTiO3) single crystal substrates through a conventional chemical vapor deposition (CVD) synthetic method. Multiple measurements have demonstrated the uniform monolayer thickness and single crystallinity of the MoS2 nanosheets as well as the atomic flatness of the heterojunction surface, both characterizing an extremely high quality of the interface. Clear evidence have been obtained for the electron transfer from the MoS2 adlayer to the SrTiO3 substrate which varies against the interface conditions. More importantly, the photoluminescence of MoS2 is significantly tailored, which is correlated with both the cleanness of the interface and the crystal orientation of the SrTiO3 substrate. These results not only shed fresh lights on the structure–property relationship of the TMDs/TMO heterostructures but also manifest the importance of the ideal interface structure for a hybridized system.
研究领域:
材料科学
·
半导体物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 3
·769
·
IF 5.076
Shijie Li,Shidai Tian,Yuan Yao,Meng He,Li Chen,Yan Zhang,Junyi Zhai
Rare earth (RE) element-doped two-dimensional (2D) transition metal dichalcogenides (TMDCs) with applications in luminescence and magnetics have received considerable attention in recent years. To date, the effect of RE element doping on the electronic properties of monolayer 2D-TMDCs remains unanswered due to challenges including the difficulty of achieving valid monolayer doping and introducing RE elements with distinct valence and atomic configurations. Herein, we report a unique strategy to grow the Sm-doped monolayer MoS2film by using an atmospheric pressure chemical vapor deposition method with the substrate face down on top of the growth source. A stable monolayer triangular Sm-doped MoS2was achieved. The threshold voltage of an Sm-doped MoS2-based field effect transistor (FET) moved from −12 to 0 V due to the p-type character impurity state introduced by Sm ions in monolayer MoS2. Additionally, the electrical performance of the monolayer MoS2-based FET was improved by RE element Sm doping, including a 500% increase of the on/off current ratio and a 40% increase of the FET’s mobility. The electronic property enhancement resulted from Sm doping MoS2, which led internal lattice strain and changes in Fermi energy levels. These findings provide a general approach to synthesize RE element-doped monolayer 2D-TMDCs and to enrich their applications in electrical devices.Keywords:monolayer MoS2;CVD growth;Sm doping;electrical performance;FET
研究领域:
材料科学
·
纳米技术
·
电子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Bobin Xu,Yingying Su,Li Li,Rui Liu,Yi Lv
Novel fluorescent thioglycollic acid (TGA) surface-functionalized single-layered thickness structured MoS 2 nanosheets were purposely synthesized by a facile one-step hydrothermal treatment of using molybdenyl acetylacetonate, TGA and sodium sulfide as precursors. During the process of synthesis, we subtly solved the problem of the poor water solubility of the precursor molybdenyl acetylacetonate, and obtained thiolated single-layer MoS 2 nanosheet (TGA-MoS 2 ) with excellent water solubility and stable fluorescence property. The fluorescence of TGA-modified MoS 2 nanosheets was significantly suppressed in the presence of dopamine (DA), and a simple sensing system for highly selective, fast, direct detection of dopamine was established. Meanwhile, the present methodology has a wide detection range of 0.05 μΜ to 20 μΜ, a comparable detection limit of 27 nM and an extremely short response time of 3 min. To understand the fast response behavior, we tried effort to explain the interaction mechanisms between TGA-MoS 2 nanosheets and the quencher DA. Further research suggests that the possible mechanism might be the charge transfer (CT) by the stacking of MoS 2 layers through C O⋯H O hydrogen boding interaction, providing a fast fluorescence sensing platform for DA determination in urine and serum sample.
研究领域:
材料科学
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分析化学
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生物医学工程
✓ 已验证
DOI
高影响因子
SURFACE AND INTERFACE ANALYSIS
·
2023
·Vol. 56
·期 1
·22-31
·
IF 1.7
Binbin Ding,Changjun Zhu,Tianming Wang,Lianbi Li,Zebin Li,Lin Cheng,Song Feng,Guoqing Zhang,Yuan Zang,Jichao Hu,Lei Li,Caijuan Xia
The epitaxial growth of high-quality and large-area monolayer (ML) MoS 2 has attracted widespread attention in recent years. Here, MoS 2 on Al 2 O 3 substrate was prepared by using atmospheric-pressure chemical vapor deposition. The process parameters such as temperature difference and distance between MoO 3 and Al 2 O 3 , nucleation temperature, and heating rate were optimized. The high MoO 3 evaporation temperature facilitates Mo vapor transport to grow ML-MoS 2 . The introduction of nucleation temperature facilitates the deposition of MoS 2 , and the morphology of the nucleation point is related to the amount of MoO 3-x deposited on Al 2 O 3 . This process optimization method is also applicable to growth MoS 2 on SiO 2 . The ML-MoS 2 with a size greater than 1 cm 2 was successfully fabricated on Al 2 O 3 and SiO 2 , which laid a foundation for the practical application of ML-MoS 2 .
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
Nanophotonics
·
2021
·Vol. 10
·期 6
·1733-1740
·
IF 8.449
Zhenming Wang,Jianxun Liu,Xiaoguo Fang,Jiawei Wang,Zhen Yin,Huilin He,Shouzhen Jiang,Meng Zhao,Zongyou Yin,Dan Luo,Ping Shum,Yan Jun Liu
We demonstrate a simple, cost-effective method to enhance the photoluminescence intensity of monolayer MoS 2 . A hexagonal symmetric Au metasurface, made by polystyrene nanosphere lithography and metal coating, is developed to enhance the photoluminescence intensity of monolayer MoS 2 . By using nanospheres of different sizes, the localized surface plasmon resonances of the Au metasurfaces can be effectively tuned. By transferring monolayer MoS 2 onto the Au metasurface, the photoluminescence signal of the monolayer MoS 2 can be significantly enhanced up to 12-fold over a square-centimeter area. The simple, large-area, cost-effective fabrication technique could pave a new way for plasmon-enhanced light-mater interactions of atomically thin two-dimensional materials.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）