Fullerene monolayer formation by spray coating

Motion of Fullerenes around Topological Defects on Metals: Implications for the Progress of Molecular Scale Devices

Research on motion of molecules in the presence of thermal noise is central for progress in two-terminal molecular scale electronic devices. However, it is still unclear what influence imperfections in bottom metal electrode surface can have on molecular motion. Here, we report a two-layer crowding study, detailing the early stages of surface motion of fullerene molecules on Au(111) with nanoscale pores in a n-tetradecane chemical environment. The motion of the fullerenes is directed by crowding of the underlying n-tetradecane molecules around the pore fringes at the liquid-solid interface. We observe in real-space the growth of molecular populations around different pore geometries. Supported by atomic-scale modeling, our findings extend the established picture of molecular crowding by revealing that trapped solvent molecules serve as prime nucleation sites at nanopore fringes.

Charge transfer and current fluctuations in single layer graphene transistors modified by self-assembled C60 adlayers

Flicker noise in a "fullerene + graphene" hybrid transistor is investigated to reveal the electrical coupling between the graphene channel and C60 adsorbates. The charge trapping and detrapping events at the C60 /graphene interface induce current fluctuations in the devices. The evolution of noise characteristics at varying temperatures indicates the different contributions related to Coulomb scattering and charge exchange kinetics.

Formation of rectangular packing and one-dimensional lines of C60 on 11-phenoxyundecanethiol self-assembled monolayers on Au(111)

The behavior of C(60) molecules deposited onto 11-phenoxyundecanethiol (phenoxy) self-assembled monolayers (SAMs) is studied using ultrahigh vacuum scanning tunneling microscopy (UHV-STM) and spectroscopy. We observe that after thermally annealing between 350 and 400 K in vacuum a combination of hexagonally close-packed islands, rectangularly packed islands, and isolated single lines of C(60) is observed when the C(60) is initially deposited on an unannealed phenoxy SAM. However, only rectangularly packed islands are found when they are deposited on a preannealed phenoxy SAM. We determine the rectangular packing to have a (2√3 × 4) rectangular unit cell with respect to the underlying Au(111) substrate. This type of C(60) structure has not been observed previously for multicomponent self-assemblies on a surface. We discuss the possible causes for the formation of this structure as well as the differences between starting on an unannealed SAM and an annealed one. This study demonstrates the capability of functionalized alkanethiol SAMs to control the growth and structure of C(60) islands during annealing depending on the structural changes of the SAM itself; by preannealing the SAM, the motion of the C(60) can be confined and unique structures resulting from interactions between the SAM molecules and C(60) can be produced.