Co-reporter:Lifei Sun;Chuanhui Chen;Dr. Qinghua Zhang;Christian Sohrt;Tianqi Zhao;Dr. Guanchen Xu;Jinghui Wang; Dong Wang; Kai Rossnagel; Lin Gu; Chenggang Tao; Liying Jiao
Angewandte Chemie 2017 Volume 129(Issue 31) pp:9109-9113
Publication Date(Web):2017/07/24
DOI:10.1002/ange.201612605
AbstractTwo-dimensional (2D) metallic transition-metal dichalcogenides (TMDCs), such as 1T-TiSe2, have recently emerged as unique platforms for exploring their exciting properties of superconductivity and the charge density wave (CDW). 2D 1T-TiSe2 undergoes rapid oxidation under ambient conditions, significantly affecting its CDW phase-transition behavior. We comprehensively investigate the oxidation process of 2D TiSe2 by tracking the evolution of the chemical composition and atomic structure with various microscopic and spectroscopic techniques and reveal its unique selenium-assisting oxidation mechanism. Our findings facilitate a better understanding of the chemistry of ultrathin TMDCs crystals, introduce an effective method to passivate their surfaces with capping layers, and thus open a way to further explore the functionality of these materials toward devices.
Co-reporter:Lifei Sun;Chuanhui Chen;Dr. Qinghua Zhang;Christian Sohrt;Tianqi Zhao;Dr. Guanchen Xu;Jinghui Wang; Dong Wang; Kai Rossnagel; Lin Gu; Chenggang Tao; Liying Jiao
Angewandte Chemie International Edition 2017 Volume 56(Issue 31) pp:8981-8985
Publication Date(Web):2017/07/24
DOI:10.1002/anie.201612605
AbstractTwo-dimensional (2D) metallic transition-metal dichalcogenides (TMDCs), such as 1T-TiSe2, have recently emerged as unique platforms for exploring their exciting properties of superconductivity and the charge density wave (CDW). 2D 1T-TiSe2 undergoes rapid oxidation under ambient conditions, significantly affecting its CDW phase-transition behavior. We comprehensively investigate the oxidation process of 2D TiSe2 by tracking the evolution of the chemical composition and atomic structure with various microscopic and spectroscopic techniques and reveal its unique selenium-assisting oxidation mechanism. Our findings facilitate a better understanding of the chemistry of ultrathin TMDCs crystals, introduce an effective method to passivate their surfaces with capping layers, and thus open a way to further explore the functionality of these materials toward devices.
Co-reporter:Lina Liu, Hailong Qiu, Jingyi Wang, Guanchen Xu and Liying Jiao
Nanoscale 2016 vol. 8(Issue 8) pp:4486-4490
Publication Date(Web):28 Jan 2016
DOI:10.1039/C5NR09089J
The controllable synthesis of MoS2 monolayers is the key challenge for their practical applications. Here we report the chemical vapor deposition (CVD) growth of single layered MoS2 by utilizing a bifunctional precursor. This precursor is a metal–organic complex which supplies both Mo sources and organic seeding promoters for the efficient CVD growth of MoS2 monolayers. The successful growth of high quality MoS2 flakes indicates that the rational design of bifunctional precursors will open up a new way for the controllable CVD growth of two-dimensional (2D) transition metal dichalcogenides (TMDCs).
Co-reporter:Jingyi Wang, Husong Zheng, Guanchen Xu, Lifei Sun, Dake Hu, Zhixing Lu, Lina Liu, Jingying Zheng, Chenggang Tao, and Liying Jiao
Journal of the American Chemical Society 2016 Volume 138(Issue 50) pp:
Publication Date(Web):November 29, 2016
DOI:10.1021/jacs.6b10414
Co-reporter:Zhixing Lu, Lifei Sun, Guanchen Xu, Jingying Zheng, Qi Zhang, Jingyi Wang, and Liying Jiao
ACS Nano 2016 Volume 10(Issue 5) pp:5237
Publication Date(Web):May 9, 2016
DOI:10.1021/acsnano.6b00961
Chemical vapor deposition (CVD) has shown great potential in synthesizing various high-quality two-dimensional (2D) transition metal dichalcogenides (TMDCs). However, the nondestruction transfer of these CVD-grown 2D TMDCs at a high yield remains a key challenge for applying these emerging materials in various aspects. To address this challenge, we designed a water-soluble transfer mediator consisting of two polymers, polyvinylpyrrolidone (PVP) and poly(vinyl alcohol) (PVA), which can form strong interactions with CVD-grown 2D TMDCs for the nondestruction transfer of these materials. With this mediator, we realized the physical transfer of CVD-grown MoS2 flakes and several other 2D TMDCs, including 2D alloys and heterostructures to a wide range of substrates at a high yield of >90% with well-retained properties as evidenced by various microscopic, spectroscopic, and electrical measurements. Field-effect transistors (FETs) made on thus-transferred CVD-grown MoS2 monolayers exhibited obviously higher mobility than those transferred by chemical method. We also constructed several artificial 2D crystals showing very strong interlayer coupling by the multiple transfer of CVD-grown 2D TMDCs monolayers with this approach. This transfer approach will make versatile CVD-grown 2D materials and their artificial stacks with pristine qualities easily accessible for both fundamental studies and practical applications.Keywords: molybdenum disulfide; transfer; transition metal dichalcogenides; two-dimensional; water-soluble polymer
Co-reporter:Dake Hu;Xin He;Lifei Sun;Guanchen Xu;Liang Zhao
Science Bulletin 2016 Volume 61( Issue 12) pp:917-920
Publication Date(Web):2016 June
DOI:10.1007/s11434-016-1091-1
Chirality-specific growth of single-walled carbon nanotubes (SWNTs) remains a challenge for their practical applications in electronics. Here, we explored the surface growth of SWNTs by utilizing the atomic-precise silver cluster complex [Ag15{1,3,5–(C≡C)3–C6H3}2(Py[8])3–(CF3SO3)3] (CF3SO3)6 (Py[8] is abbreviation for octamethylazacalix[8] pyridine) as a catalyst precursor. The diameters of most acquired SWNTs distributed in the range of 1.2–1.4 nm, which is suitable for making high performance field-effect transistors. The high quality of the obtained SWNTs was evidenced by Raman spectroscopy and electrical measurements. Successful growth of high quality SWNTs in this study foresees that rational design of metal-organic complexes as growth catalysts can open up a new avenue for the controllable synthesis of SWNTs.
Co-reporter:Guanchen Xu, Xinsheng Wang, Xiao Chen and Liying Jiao
RSC Advances 2015 vol. 5(Issue 23) pp:17782-17785
Publication Date(Web):05 Feb 2015
DOI:10.1039/C4RA13707H
The controlled synthesis of high quality one-dimensional V2O3 materials is critical for addressing the fundamental aspects of metal–insulator transition (MIT) in these materials. Here we developed a controllable approach for synthesizing pristine V2O3 nanobelts by reducing hydrothermally synthesized V2O5 nanobelts in the gas phase. The obtained V2O3 nanobelts showed high crystallinity and purity with length up to tens of micrometers. We investigated the changes in electrical conductance, magnetic susceptibility and Raman spectra that accompanied the phase transition of nanobelts with variable-temperature measurements. The MIT behaviour of V2O3 nanobelts was very similar to that of the bulk materials while the magnetic phase transition of V2O3 was suppressed in the nanobelts due to the finite size effect. This simple and reliable synthesis approach makes the V2O3 nanobelts easily accessible for exploring their fundamental properties and potential applications in novel electronic devices.
Co-reporter:Qi Zhang;Xu Xiao;Dr. Ruiqi Zhao;Danhui Lv;Guanchen Xu;Zhixing Lu;Lifei Sun;Shizhe Lin;Xiang Gao; Jun Zhou; Chuanhong Jin; Feng Ding; Liying Jiao
Angewandte Chemie International Edition 2015 Volume 54( Issue 31) pp:8957-8960
Publication Date(Web):
DOI:10.1002/anie.201502461
Abstract
Controlled stacking of different two-dimensional (2D) atomic layers will greatly expand the family of 2D materials and broaden their applications. A novel approach for synthesizing MoS2/WS2 heterostructures by chemical vapor deposition has been developed. The successful synthesis of pristine MoS2/WS2 heterostructures is attributed to using core–shell WO3−x/MoO3−x nanowires as a precursor, which naturally ensures the sequential growth of MoS2 and WS2. The obtained heterostructures exhibited high crystallinity, strong interlayer interaction, and high mobility, suggesting their promising applications in nanoelectronics. The stacking orientations of the two layers were also explored from both experimental and theoretical aspects. It is elucidated that the rational design of precursors can accurately control the growth of high-quality 2D heterostructures. Moreover, this simple approach opens up a new way for creating various novel 2D heterostructures by using a large variety of heteronanomaterials as precursors.
Co-reporter:Qi Zhang;Xu Xiao;Dr. Ruiqi Zhao;Danhui Lv;Guanchen Xu;Zhixing Lu;Lifei Sun;Shizhe Lin;Xiang Gao; Jun Zhou; Chuanhong Jin; Feng Ding; Liying Jiao
Angewandte Chemie 2015 Volume 127( Issue 31) pp:9085-9088
Publication Date(Web):
DOI:10.1002/ange.201502461
Abstract
Controlled stacking of different two-dimensional (2D) atomic layers will greatly expand the family of 2D materials and broaden their applications. A novel approach for synthesizing MoS2/WS2 heterostructures by chemical vapor deposition has been developed. The successful synthesis of pristine MoS2/WS2 heterostructures is attributed to using core–shell WO3−x/MoO3−x nanowires as a precursor, which naturally ensures the sequential growth of MoS2 and WS2. The obtained heterostructures exhibited high crystallinity, strong interlayer interaction, and high mobility, suggesting their promising applications in nanoelectronics. The stacking orientations of the two layers were also explored from both experimental and theoretical aspects. It is elucidated that the rational design of precursors can accurately control the growth of high-quality 2D heterostructures. Moreover, this simple approach opens up a new way for creating various novel 2D heterostructures by using a large variety of heteronanomaterials as precursors.
Co-reporter:Guanchen Xu;Xinsheng Wang;Yupeng Sun;Xiao Chen;Jingying Zheng
Nano Research 2015 Volume 8( Issue 9) pp:2946-2953
Publication Date(Web):2015 September
DOI:10.1007/s12274-015-0799-6
Edge effects are predicted to significantly impact the properties of low dimensional materials with layered structures. The synthesis of low dimensional materials with copious edges is desired for exploring the effects of edges on the band structure and properties of these materials. Here we developed an approach for synthesizing MoS2 nanobelts terminated with vertically aligned edges by sulfurizing hydrothermally synthesized MoO3 nanobelts in the gas phase through a kinetically driven process; we then investigated the electrical and magnetic properties of these metastable materials. These edge-terminated MoS2 nanobelts were found to be metallic and ferromagnetic, and thus dramatically different from the semiconducting and nonmagnetic two-dimensional (2D) and three-dimensional (3D) 2H-MoS2 materials. The transitions in electrical and magnetic properties elucidate the fact that edges can tune the properties of low dimensional materials. The unique structure and properties of this one-dimensional (1D) MoS2 material will enable its applications in electronics, spintronics, and catalysis.
Co-reporter:Xinsheng Wang ; Hongbin Feng ; Yongmin Wu
Journal of the American Chemical Society 2013 Volume 135(Issue 14) pp:5304-5307
Publication Date(Web):March 14, 2013
DOI:10.1021/ja4013485
The controlled synthesis of highly crystalline MoS2 atomic layers remains a challenge for the practical applications of this emerging material. Here, we developed an approach for synthesizing MoS2 flakes in rhomboid shape with controlled number of layers by the layer-by-layer sulfurization of MoO2 microcrystals. The obtained MoS2 flakes showed high crystallinity with crystal domain size of ∼10 μm, significantly larger than the grain size of MoS2 grown by other methods. As a result of the high crystallinity, the performance of back-gated field effect transistors (FETs) made on these MoS2 flakes was comparable to that of FETs based on mechanically exfoliated flakes. This simple approach opens up a new avenue for controlled synthesis of MoS2 atomic layers and will make this highly crystalline material easily accessible for fundamental aspects and various applications.
Co-reporter:Dake Hu, Xin He, Lifei Sun, Guanchen Xu, ... Liang Zhao
Science Bulletin (June 2016) Volume 61(Issue 12) pp:917-920
Publication Date(Web):1 June 2016
DOI:10.1007/s11434-016-1091-1
Chirality-specific growth of single-walled carbon nanotubes (SWNTs) remains a challenge for their practical applications in electronics. Here, we explored the surface growth of SWNTs by utilizing the atomic-precise silver cluster complex [Ag15{1,3,5–(C≡C)3–C6H3}2(Py[8])3–(CF3SO3)3] (CF3SO3)6 (Py[8] is abbreviation for octamethylazacalix[8] pyridine) as a catalyst precursor. The diameters of most acquired SWNTs distributed in the range of 1.2–1.4 nm, which is suitable for making high performance field-effect transistors. The high quality of the obtained SWNTs was evidenced by Raman spectroscopy and electrical measurements. Successful growth of high quality SWNTs in this study foresees that rational design of metal-organic complexes as growth catalysts can open up a new avenue for the controllable synthesis of SWNTs.
