Optically enhanced charge transfer between C₆₀ and single-wall carbon nanotubes in hybrid electronic devices

In this article we probe the nature of electronic interactions between the components of hybrid C₆₀-carbon nanotube structures. Utilizing an aromatic mediator we selectively attach C₆₀ molecules to carbon nanotube field-effect transistor devices. Structural characterization via atomic force and transmission electron microscopy confirm the selectivity of this attachment. Charge transfer from the carbon nanotube to the C₆₀ molecules is evidenced by a blue shift of the Raman G⁺ peak position and increased threshold voltage of the transistor transfer characteristics. We estimate this charge transfer to increase the device density of holes per unit length by up to 0.85 nm^-1 and demonstrate further optically enhanced charge transfer which increases the hole density by an additional 0.16 nm ^-1.