| AVS 55th International Symposium & Exhibition | |
| Biological, Organic, and Soft Materials Focus Topic | Thursday Sessions |
| Session BO+EM+BI+NC-ThM |
| Session: | Semiconducting Biointerfaces and Sensors |
| Presenter: | B. Diaconescu, University of New Hampshire |
| Authors: | B. Diaconescu, University of New Hampshire T. Yang, Michigan State University S. Berber, Michigan State University M. Jazdzyk, University of New Hampshire G. Miller, University of New Hampshire D. Tomanek, Michigan State University K. Pohl, University of New Hampshire |
| Correspondent: | Click to Email |
Self-assembled organic thin films have a great number of practical applications, ranging from sensors and biological interfaces in medical implants to organic electronics and photovoltaics. Generally speaking, self-assembled monolayers (SAMs) form as a result of a delicate balance between competing molecule–substrate and intermolecular interactions. Therefore, to control such self-assembly processes in a useful way, it is mandatory to understand how this balance reflects onto the SAM's final structure. Here, we present a combined STM and DFT study of the self-assembly of C60 molecules functionalized with long alkane chains, F-C60, on the (111) surface of silver. We find that F-C60 molecules lay down on the Ag surface and form a complex zigzag like pattern with an oblique unit cell of 4 nm by 2.5 nm and two molecules per basis. The C60s are placed at a larger than van der Waals distance. The symmetry of the functionalized C60 self-assembled monolayer is dictated by the alkane–surface interaction while the size of the unit cell is a consequence of the in-plane intermolecular interactions. These results show that C60s can be assembled in a two-dimensional and non-compact molecular array and suggest a way to control their surface density via appropriate chemical functionalization.
*This work was supported by the Nanoscale Science and Engineering Center for High-rate Nanomanufacturing (NSF NSEC-425826). Partial support has been provided by the NSF-NIRT grant ECS-0506309."