Electrical transport properties of small diameter single-walled carbon nanotubes aligned on ST-cut quartz substrates

A method is introduced to isolate and measure the electrical transport properties of individual single-walled carbon nanotubes (SWNTs) aligned on an ST-cut quartz, from room temperature down to 2 K. The diameter and chirality of the measured SWNTs are accurately defined from Raman spectroscopy and atomic force microscopy (AFM). A significant up-shift in the G-band of the resonance Raman spectra of the SWNTs is observed, which increases with increasing SWNTs diameter, and indicates a strong interaction with the quartz substrate. A semiconducting SWNT, with diameter 0.84 nm, shows Tomonaga-Luttinger liquid and Coulomb blockade behaviors at low temperatures. Another semiconducting SWNT, with a thinner diameter of 0.68 nm, exhibits a transition from the semiconducting state to an insulating state at low temperatures. These results elucidate some of the electrical properties of SWNTs in this unique configuration and help pave the way towards prospective device applications

Embedding a Carbon Nanotube across the Diameter of a Solid State Nanopore

A fabrication method for positioning and embedding a single-walled carbon nanotube (SWNT) across the diameter of a solid state nanopore is presented. Chemical vapor deposition (CVD) is used to grow SWNTs over arrays of focused ion beam (FIB) milled pores in a thin silicon nitride membrane. This typically yields at least one pore whose diameter is centrally crossed by a SWNT. The final diameter of the FIB pore is adjusted to create a nanopore of any desired diameter by atomic layer deposition, simultaneously embedding and insulating the SWNT everywhere but in the region that crosses the diameter of the final nanopore, where it remains pristine and bare. This nanotube-articulated nanopore is an important step towards the realization of a new type of detector for biomolecule sensing and electronic characterization, including DNA sequencing.Engineering and Applied SciencesMolecular and Cellular BiologyPhysic

Direct Patterning of Boron-doped Amorphous Carbon Using Focused Ion Beam-assisted Chemical Vapor Deposition

The deposition of boron-doped amorphous carbon thin films on SiO2 substrate was achieved via a focused ion beam-assisted chemical vapor deposition of triphenyl borane (C18H15B) and triphenyl borate (C18H15BO3). The existence of boron in the deposited film from triphenyl borane, with a precursor temperature of 90 {\deg}C, was confirmed by a core level X-ray photoelectron spectroscopy analysis. The film exhibited a semiconducting behavior with a band gap of 285 meV. Although the band gap was decreased to 197 meV after an annealing process, the film was still semiconductor. Additionally, a drastic reduction of the resistance on the deposited film by applying pressures was observed from an in-situ electrical transport measurements using a diamond anvil cell