Tony Heinz - Atomically Thin Two-Dimensional Materials - Graphene and Beyond

Atomically Thin Two-Dimensional Materials - Graphene and Beyond

Prof. Tony F. Heinz

Bio: Tony Heinz is a Professor of Applied Physics and Photon Science at Stanford University and the Director of the Chemical Sciences Division at the SLAC National Accelerator Laboratory. Heinz received a BS degree in Physics from Stanford University and a PhD degree, also in Physics, from UC Berkeley in 1982.  He was subsequently at the IBM Research Division in Yorktown Heights, NY until he joined Columbia University in 1995 as a Professor of Electrical Engineering and Physics. At Columbia, he served as a Scientific Director of the Columbia Nanoscale Science and Engineering Center (NSEC) and of the Energy Frontier Research Center (EFRC). He was the President of the Optical Society of America in 2012.  Heinz joined Stanford in 2015.

Heinz's research has centered on the elucidation of the properties and dynamics of nanoscale materials primarily through the application of optical and laser techniques.  His research on surfaces, interfaces, and nanoscale materials, including carbon nanotubes, graphene and other 2D materials, has been recognized by Optics Prize of the International Commission for Optics, a Research Award of the von Humboldt Foundation, the Julius Springer Prize for Applied Physics, and the Isakson Prize of the American Physical Society.

Abstract: Graphene, a single atomic layer of carbon atoms, has attracted great attention worldwide because of its potential for novel science and technology.  Recently, this interest has expanded to the much wider class of 2D materials that occur as layers of van-der-Waals crystals. While preserving graphene’s flexibility and tunability by external perturbations, atomically thin layers of this broader set of materials provides access to more varied electronic and optical properties, including semiconducting and insulating behavior.

We will describe some of the distinctive properties of the expanding class of atomically thin 2D materials, with an emphasis on the novel optical properties of these systems.  Graphene has now been investigated across a spectral range from the THz to the UV.  The optical properties reveal much interesting physics and also show strong tunability in response by means of external gating. Recently, atomically thin layers of semiconductors in the family of transition metal dichalcogenides (MX₂ where M = Mo, W and X = S, Se, Te) have also been prepared and investigated.  Although weak light emitters in the bulk, at monolayer thickness these materials emit light efficiently. We will describe these and some of the other surprising characteristics of these systems at monolayer thickness, as well as the new properties that  emerge when we combine such ultrathin layers with one another in tailor-made vertical heterostructures.