报告题目： Understanding and tailoring properties of graphene for potential applications in nanoelectronics

报 告 人： Prof. Ze Xiang Shen

School of Physical and Mathematical Sciences Nanyang Technological University

主 持 人：卢革宇 教授

报告时间：2015年7月14日9:30

报告地点：唐敖庆楼D311报告厅

主办单位：电子科学与工程学院

集成光电子学国家重点联合实验室

Dr. Ze Xiang Shen is a Professor in the School of Physical and Mathematical Sciences, and the School of Materials Science and Engineering, Nanyang Technological University. He is the Program Chair of the Interdisciplinary Graduate School. He concurrently holds the position of Co-Director, Centre for Disruptive Photonics Technologies.

His main research areas include 2D materials, especially graphene and TMD materials. His work involves spectroscopic and theoretical study of few-lay graphene and folded graphene, inter-layer coupling and the effect of stacking dependence on the electronic structure of TMD materials. He also works graphene intercalation study, graphene based composites for energy harvesting (Li Ion batteries and supercapacitors) and nano electronics; 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 study of plasmonics structures where some very fundamental questions remain to be answered. He was awarded the NTU Nanyang Award for Research and Innovation 2009 as well as the Gold Medal for Research Excellence by Institute of Physics Singapore in 2011. Shen authored over 400 peer reviewed journal papers, 4 book chapters, edited 3 books and over 300 conference papers. He has a citation of >12,000 and H-index of 60.

Graphene has many outstanding and unique electrical, mechanical, thermal, optical, and chemical properties. It is also the thinnest possible materials as it is only 1-atom thick. Such properties make graphene ideally suited for a wide range of applications. However the lack of an energy band gap and its low charge concentration in graphene severely limit its potential applications in nano electronics.

In this talk, I will present our results of graphene study: 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, edge closure and ABC/ABA tri-layer transformation, hydrogenation, and studies of graphene with mis-oriented layers and applications in energy storage.