Fullerene Nanostructure-Coated Channels Activated by Electron Beam Lithography for Resistance Switching

Fullerenes, which are spherical molecules composed entirely of carbon, have attractive homogeneous shapes at subnanometer sizes and inherent physical and chemical properties that make them promising for use in nanoelectronics. In addition, fullerenes can be chemically functionalized with substitutional elements, which have been incorporated into devices to substantially improve their transport properties. The chemically functionalized fullerenes are known as fullerene derivatives. Using the chemically functionalized fullerene pyrrolidine tris-acid (CPTA), we developed a new device fabrication scheme for a fullerene resistance-switching element generated by the polymerization and depolymerization of C60 polymer strings. To take advantage of the CPTA property, whereby it forms strong interactions with the surface of a substrate by strengthening the chemical bonds, a uniform thin CPTA film was spin-coated, and conductive fullerene polymerization was subsequently stimulated by a designed scan with an electron beam lithography (EBL) preset. The polymerized channel showed negative differential resistance in its current-voltage characteristics and performed twostate resistance switching, indicating that the polymerization and depolymerization of the C60 polymer strings were alternatively controlled according to the external voltage input. EBL fabrication with solution-based nanomaterial coating has the potential of a bottom-up scheme for nanoelectronics, allowing for the design of intrinsic material properties.