Controllable crystalline structure of fullerene nanorods and transport properties of an individual nanorod

Single-crystalline pristine C-60 nanorods with fcc crystal structure were synthesized by solvent-induced self-assembly followed by heat treatment. The length and length-to-width ratio of C-60 nanorods were tunable by controlling the concentration of C-60 molecules in the stock solution. Devices consisting of individual fcc nanorods were fabricated by a focused ion beam ( FIB) technique. For comparison, nanorods of hcp structure were synthesized and devices consisting of individual hcp nanorods were fabricated also. The transport properties of an individual C-60 nanorod suggested that the fcc nanorods exhibited higher conductivity than the hcp nanorods, i.e., the transport properties of C-60 nanorods exhibited a strong phase dependence. The temperature dependence of the devices indicated the thermally activated carrier injection of the fcc nanorods. The activation energies of the nanorods are much smaller than those of the bulk crystals of C-60, indicating easier carrier injection of the fcc nanorods and their potential applications for the fabrication of efficient nanodevices. The good operational stability of individual C-60 nanorod based devices under sustained high dc voltage suggested their application as stable units in micro electronics or chemical sensor systems.