Low-dimensional materials functioning at the nanoscale are a critical component for a variety of current and future technologies. From the optimization of light harvesting solar technologies to large-scale catalytic processes, key physical phenomena are occurring at the nanometer and atomic length-scales and predominately at interfaces. For instance, graphene is a nearly ideal two-dimensional conductor that is comprised of a single sheet of hexagonally packed carbon atoms. In order fully realize the potential of graphene for novel electronic applications, large-scale synthesis of high quality graphene and the ability to control the electronic properties of this material on a nanometer length scale are key challenges. In addition to graphene, we are interested in exploring the synthesis of low-dimensional materials that do not occur in nature. This talk will highlight how scanning probe microscopy presents a series of powerful experimental tools that can overcome several challenges and allow for the direct characterization of several advanced materials. This talk will also cover our most recent discovery and synthesis of new two-dimensional (2D) boron allotropes (borophenes). This discovery of metallic 2D sheets of boron presents almost ideal example of the synergy between predictive modeling resulting in the experimental realization of a designer materials.
Dr. Nathan Guisinger received his PhD in materials science and engineering from Northwestern University where he studied charge transport through individual organic molecules at the atomic scale (Advisor: Professor Mark Hersam). Prior to joining Argonne, Nathan worked at NIST where he participated in the first atomic scale investigations of the electronic properties of graphene utilizing ultrahigh vacuum scanning tunneling microscopy (STM) (Advisor: Dr. Joseph Stroscio). Nathan joined the Quantum and Energy Materials group in November 2007 as an Assistant Scientist, and was promoted to Associate Scientist in 2012. At the CNM, Nathan developed experimental techniques enabling the first cross-sectional STM studies of complex oxides and heterostructures. He is also very interested in chiral selectivity observed in the molecular self-assembly of amino acids. More recently at the CNM, he has succeeded in the first growth of graphene on Ag(111) surface and the investigation of graphene nanoribbons on a Ge semiconductor surfaces. Moreover, his exploration of Si growth on Ag(111) expanded our understanding that “silicene” (two-dimensional silicon) reported in the literature was in fact surface alloys and the precipitation of Si(111). Finally, guided by predictive material design, his group is leading the experimentally discover borophenes, a new class of boron allotropes based on 2D materials, opening the door to a new field of materials research.