报告人：Prof. Zexiang Shen
单位： Nanyang Technological University, Singapore
日期：5月11日 (星期三) 上午 9：30
地点：南楼203

摘要：Graphene exhibits many exciting properties, such as anomalously quantized Hall effects, massless Dirac-Fermions like charge carrier, existence of a minimum conductivity, which make it promising material for the future nano-electronic devices. All these properties are originated from its unique band structure whose conical valence and conduction bands meet at the Dirac point in Brillouin zone.

In this talk, I will present our results of graphene study: new understanding on graphene intercalation, and properties of folded and mis-oriented graphenes.  With the availability of few-layer graphene, we shed new light on the mechanism of intercalation of graphite which is not possible before. Folded graphene sheets exhibit two-dimensional Dirac-like (single layer graphene-like) character of electronic states and with reduction of Fermi velocity. For applications in nano-electronic devices and energy harvesting, opening of the band gap is needed. On the other hand, many of the unique properties of graphene are accorded to that of single layer graphene (SLG). But it is very difficult to fabricate large single crystalline SLG samples for practical applications. It would be most desirable to modify few-layer graphene (FLG) samples so that they have similar properties as that of SLG. I will also present our results in modifying graphene for various applications, including modifying edge chirality, hydrogenation, and studies of graphene with mis-oriented layers. 

Short Bio of speaker

Dr. Ze Xiang Shen is a Professor of Physics at the School of Physical and Mathematical Sciences, Nanyang Technological University (NTU). He is also the School’s Associate Chair in charge of academic and graduate studies.

His main research areas include carbon related materials, especially graphene.  His work involves growth of large area graphene for energy harvesting (batteries, H storage, electrodes) and nano electronics applications; fundamental study of graphene such as electronic structures, doping, energy band gaps.  He also works on developing near-field Raman spectroscopy/imaging techniques and the characterization of strain in nanometer scale as well as nanophotonic structures using near field techniques.  He was awarded the NTU Nanyang Award for Research and Innovation 2009. Shen authored over 250 peer reviewed journal papers, 3 book chapters, edited one book and over 200 conference papers.