Large Area Self-Ordered Parallel C₆₀ Molecular Nanowire Arrays on Si(110) Surfaces
Ie-Hong Hong1*, Chia-Jung Gao2
1Department of Electrophysics, National Chiayi University, Chiayi, Taiwan
2Institute of Optoelectronics and Solid State Electronics, National Chiayi University, Chiayi, Taiwan
* presenting author:Ie-Hong Hong, email:ihhong@mail.ncyu.edu.tw
We report that the large-scale self-organization of well-ordered parallel C₆₀ molecular nanowire arrays with tunable structures on Si(110) surfaces can be achieved through a site-selective anchoring method. Our scanning tunneling microscopy investigations show that the preferential trapping of C₆₀ molecules atop Si pentagons on upper terraces of the C₆₀-induced Si(110) reconstructed surface leads to the formation of long-range ordered C₆₀ molecular nanowires with a C₆₀ triplet as a repeat unit along each Si upper terrace (i.e., a Si nanowire). Scanning tunneling spectroscopy measurements show a large energy gap of ~3.0 eV between the highest occupied molecular orbital and the lowest unoccupied molecular orbital of the C₆₀ molecules within a C₆₀ triplet, indicating a relatively weak C₆₀-Si(110)interaction that is the main driving force for the site-selective anchoring atop Si pentagons via the geometric matching. The formation of ordered parallel C₆₀-tetramer nanowire arrays upon further C₆₀ adsorption confirms this self-ordering mechanism. Such mesoscopically ordered hybrid C₆₀/Si nanojunction arrays with the unmodified C₆₀ on periodic Si nanowires were not yet observed before. The ability to grow the large-area parallel fullerene nanowire arrays with tunable structures on Si(110) represents an important step toward the engineering of advanced Si-based molecular nanoelectronics and quantum computation.


Keywords: fullerene, nanowire, self-organization , Si(110), scanning tunneling microscopy