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| Two-dimensional (2D) Atomic Layers: Synthesis, Characterizations and Applications |
Presented by Zheng Liu, Nanyang Assistant Professor, National Foundation Research (NRF) Fellow Time: 10:00 a.m., June 13, 2014 Location: A718, SINANO Abstract: Recent times have seen a surge of activity in the exploration of two dimensional atomic layered structures with a range of properties. Here we will discuss our recent efforts in exploring various two-dimensional materials including graphene, hexagonal boron nitride (h-BN), various dichalcogenide systems and hybrid atomic layers consisting of multiple compositions. Scalable synthesis through vapour deposition of several of these structures will be discussed. Understanding of defects such as grain boundaries, edges and point defects in these structures is important for manipulating physical properties in these materials. Our efforts in manipulating these layers into creating vertically stacked hybrids as well as laterally engineered layers will be described. Overall, the talk will summarize our recent progress in synthesizing and characterizing atomically engineered layers of materials with a wide range of properties and their applications on active nano-systems and high performance energy components, e.g. resonators, photodetectors, high-density capacitors, ultrafast lithium storage etc. Reference: [1]. Y. Gong, G. Shi, Z. Zhang, W. Zhou, J. Jung, W. Gao, L. Ma, Y. Yang, S. Yang, G. You, R. Vajtai, Q. Xu, A. MacDonald, B. I. Yakobson, J. Lou, Z. Liu*, and P.M. Ajayan Direct Chemical Conversion of Graphene to Boron, Nitrogen and Carbon Containing Atomic Layers. Nature Communications, 2014, 5, 319 (Corresponding author) [2]. Y.J. Gong,* Z. Liu,* A.R. Lupini,* G. Shi, J.H. Lin, S. Najmaei, Z. Lin, A.L. Elías, A. Berkdemir, G. You, H. Terrones, M. Terrones, R. Vajtai, S.T. Pantelides, S.J. Pennycook, J. Lou, W. Zhou, P.M. Ajayan. Band Gap Engineering and Layer-by-Layer Mapping of Selenium-Doped Molybdenum Disulfide. Nano Letters 2014, 14, 442. [3]. Z. Liu, Y.J. Gong et al., “Ultrathin high-temperature oxidation-resistant coatings of hexagonal boron nitride”, Nature Communications, 2013, 4, Article number: 2541. [4]. S. Najmaei,* Z. Liu,* W. Zhou, X. Zou, G. Shi, S. Lei, B. I. Yakobson, J.-C. Idrobo, P. M. Ajayan, J. Lou. Vapour phase growth and grain boundary structure of molybdenum disulphide atomic layers. Nature Materials 2013, 12, 754-759. (*Equally first author) [5]. Z. Liu, L. Ma, G. Shi, W. Zhou, Y. Gong, S. Lei, X. Yang, J. Zhang, J. Yu, K. P. Hackenberg, A. Babakhani, J.-C. Idrobo, R. Vajtai, J. Lou, P. M. Ajayan. In-plane heterostructures of graphene and hexagonal boron nitride with controlled domain sizes. Nature Nanotechnology 2013, 8, 119-24.Z. [6]. Z. Liu, Y. Zhan, G. Shi, S. Moldovan, M. Gharbi, L. Song, L. Ma, W. Gao, J. Huang, R. Vajtai, F. Banhart, P. Sharma, J. Lou, P. M. Ajayan. Anomalous high capacitance in a coaxial single nanowire capacitor. Nature communications 2012, 3, 879-879. [7]. Z. Liu, L. Song, S. Zhao, J. Huang, L. Ma, J. Zhang, J. Lou, P. M. Ajayan. Direct growth of graphene/hexagonal boron nitride stacked layers. Nano Letters 2011, 11, 2032. Biography: Dr. Zheng Liu received his B.S. degrees (2005) at Nankai University (China), and completed his Ph.D at National Center for Nanoscience and Technology (NCNST, China), working on the synthesis and energy harvest of carbon nanotubes. He then worked in Prof. Pulickel M. Ajayan and Prof. Jun Lou’s groups as a joint postdoc research fellow (2010~2012) andresearch scientist (2012~2013) at Rice University (USA), focusing on the synthesis and applications of two-dimensional (2D) crystals, including graphene, hexagonal boron nitride, oxides and transition metal dichalcogenides (TMD: MoS2, MoSe2 etc). As a young pioneer in 2D materials research, he has made great contributions not only the synthesis of 2D heterostructures such as vertical and lateral graphene/h-BN, but also the 2D materials based nanoelectronics, active nano-systems and high performance energy components, e.g. resonators, graphene photodetectors, high-density capacitors, ultrafast lithium storage. He has published more than 50 peer-reviewed papers in top journals including 6 papers in Nature serial journal (Nature Materials, Nature Nanotechnology and Nature Communications); 14 in Nano Letters; 5 in Advanced Maters; 5 in ACS Nano since 2011, with total citations more than 1500. There are 10 paper gets a citation more than 50 citations and 4 papers more than 100. These works have also been reported by Science daily, IEEE spectrum, etc., and highlighted by the top journals such as Nature Physics, Nature Nanotechnology, Chem Int Ed, etc. He was also a recipient of the World Technology Award in Energy category in 2012. This award has been presented as a way to honor those in doing “the innovative work of the greatest likely long-term significance.” He was awarded the prestigious Singapore NRF Fellowship and Nanyang Assistant Professorship in 2013. Current Research Interests: Synthesis of large-scale and high-quality two-dimensional (2D) materials, e.g. graphene, hexagonal boron nitrides (h-BN), transition metal dichalcogenides (TMDs); Synthesis of ternary 2D materials such as h-BNC and doped TMDs; Hybridized architectures of 2D materials; Applications of 2D materials on high-performance optical and electronic devices. Zheng Liu School of Materials Science and Engineering School of Electrical and Electronic Engineering Nanyang Technological University N4.1-01-10, 50 Nanyang Ave., Singapore 639798 Tel: +65-6513 7352 Email: z.liu@ntu.edu.sg http://www3.ntu.edu.sg/home/z.liu/ |
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