| AVS 57th International Symposium & Exhibition | |
| Graphene Focus Topic | Tuesday Sessions |
| Session GR+TF-TuA |
| Session: | Graphene and 2D Nanostructures |
| Presenter: | M.C. Hersam, Northwestern University |
| Correspondent: | Click to Email |
Chemically functionalized semiconductor surfaces have been widely explored due to their potential for enabling molecular electronic and sensing devices that are compatible with conventional microelectronic technology [1]. Thus far, the vast majority of work in this field has focused on established semiconductors including silicon, germanium, and gallium arsenide. Meanwhile, the condensed matter physics community has diverted substantial experimental and theoretical effort to graphene, an emerging electronic material with superlative carrier mobility and exotic charge transport phenomena such as the quantum Hall effect.
In an attempt to unify these two fields, we have been exploring strategies for forming and interrogating organic self-assembled monolayers on graphene surfaces. In particular, we have recently demonstrated that self-assembled monolayers of perylene-3,4,9,10-tetracarboxylic-dianhydride (PTCDA) can be formed on graphene surfaces via gas-phase deposition in ultra-high vacuum (UHV) environments at room temperature [2]. Molecular-scale resolution scanning tunneling microscopy (STM) images reveal long-range order in the PTCDA monolayers, while scanning tunneling spectroscopy (STS) measurements yield distinct electronic features associated with the PTCDA that are not observed on pristine graphene.
In addition to UHV STM characterization, this talk will summarize our most recent efforts to nanopattern self-assembled monolayers on graphene at the sub-10 nm scale. Nanopatterning chemically functionalized graphene presents opportunities for tailoring the electronic and chemical properties of graphene nanoribbons in addition to providing a molecular-scale resolution template for subsequent materials growth on graphene surfaces.
[1] M. A. Walsh and M. C. Hersam, “Atomic-scale templates patterned by ultrahigh vacuum scanning tunneling microscopy on silicon,” Annual Review of Physical Chemistry, 60, 193 (2009).
[2] Q. H. Wang and M. C. Hersam, “Room-temperature molecular-resolution characterization of self-assembled organic monolayers on epitaxial graphene,” Nature Chemistry, 1, 206 (2009).