Title: Two-Dimensional Layer Materials and Topological Insulators

Speaker: Professor Yi Cui, Stanford University

Location: Room 111, Physics Building

Time: 10:00-11:00am, Oct. 17th, 2013

Abstract:

Two-dimensional (2D) layer-structured chalcogenides host many interesting physical and chemical phenomena such as topological insulator and intercalation. Their nanostructures represent novel candidates to host those phenomena. Here we present our study in the past seven years on chemistry and physics of 2D chalcogenide nanoribbons and nanoplates. First, we developed the synthesis of a variety of 2D nanostructures including nanoribbons and nanoplates. Second, we have developed a new method of zero-valent intercalation which allows unprecedented high levels of various metal intercalants inserted into the van der Waals gaps. The resulted optical properties and electrical conductance change drastically. Third, we have fabricated single nanostructure electrical transport devices. Using topological insulator nanostructures, we observed interesting physical phenomena including Aharonov–Bohm oscillations from topological surface electrons, ambipolar transport with effective control of the Fermi level into the bulk bandgap and across the Dirac Point, and localization effects emerging from the surface electrons in confined dimensions.

Biography:

Yi Cui received a Bachelor’s degree in Chemistry in 1998 at the University of Science and Technology of China, Ph.D in Chemistry in 2002 at Harvard University. He was Miller Postdoctoral Fellow at the University of California, Berkeley. In 2005 he became an Assistant Professor in Department of Materials Science and Engineering at Stanford University. In 2010 he was promoted to an Associate Professor with tenure and named as David Filo and Jerry Yang Faculty Scholar. His current research is on nanomaterials design for energy, environment and biology, and the exploration of 2D nanomaterials and 3D scaffolds.

Yi Cui is an Associate Editor of Nano Letters. He is a co-director of the Bay Area Photovoltaics Consortium, which is funded with $25M by the US Department of Energy. He has founded Amprius Inc., a company to commercialize the high-energy battery technology. He has received the IUPAC Distinguished Award for Novel Materials and Synthesis (2013), Scientist in Residence of University of Duisburg-Essen (2013), Next Power Visiting Chair Professorship (National Tsinghua University, 2013), the Wilson Prize (2011), the David Filo and Jerry Yang Faculty Scholar (2010), the Sloan Research Fellowship (2010), the Global Climate and Energy Project Distinguished Lecturer (2009), KAUST Investigator Award (2008), ONR Young Investigator Award (2008), MDV Innovators Award (2007), Terman Fellowship (2005), the Technology Review World Top Young Innovator Award (2004), Miller Research Fellowship (2003), Distinguished Graduate Student Award in Nanotechnology (Foresight Institute, 2002), Gold Medal of Graduate Student Award (Material Research Society, 2001).