Conversion of metallic single-walled carbon nanotube networks to semiconducting through electrochemical ornamentation.

Field-effect transistors (FETs) that incorporate single-walled carbon nanotube (SWNT) networks experience decreased on-off current ratios (I(on)/I(off)) due to the presence of metallic nanotubes. Herein, we describe a method to increase I(on)/I(off) without the need for either specialized SWNT growth methods or post growth processing steps to remove metallic nanotubes. SWNTs that were grown using conventional arc discharge methods were deposited from aqueous suspension.

Bulk purification and deposition methods for selective enrichment in high aspect ratio single-walled carbon nanotubes.

Aqueous batch processing methods for the concurrent purification of single-walled carbon nanotube (SWNT) soot and enrichment in high aspect ratio nanotubes are essential to their use in a wide variety of electronic, structural, and mechanical applications. This manuscript presents a new route to the bulk purification and enrichment of unbundled SWNTs having average lengths in excess of 2 μm. Iterative centrifugation cycles at low centripetal force not only removed amorphous C and catalyst nanoparticles but also allowed the enhanced buoyancy of surfactant encapsulated, unbundled, high aspect ratio SWNTs to be used to isolate them in the supernatant.

Growth of Ge nanofilms using electrochemical atomic layer deposition, with a "bait and switch" surface-limited reaction.

Ge nanofilms were deposited from aqueous solutions using the electrochemical analog of atomic layer deposition (ALD). Direct electrodeposition of Ge from an aqueous solution is self-limited to a few monolayers, depending on the pH. This report describes an E-ALD process for the growth of Ge films from aqueous solutions.

Macroscopic electrical properties of ordered single-walled carbon nanotube networks.

Creation of large-scale arrays of single-walled carbon nanotubes (SWNTs) with defined orientation and density is of central importance for obtaining functional electronic device structures that incorporate these nanoscaled systems. This manuscript describes how the macroscopic electrical properties of 2D SWNT networks vary controllably with the microscopic alignment individual SWNTs in the network. These studies indicate that "orthogonal" SWNT structures provide enhanced reproducibility and conductivity, when compared to deposits of highly aligned SWNTs.

Incorporation of single-walled carbon nanotubes into functional sensor applications.

Due to their extreme sensitivity to surface adsorption events, there has been great interest in incorporating single walled carbon nanotubes (SWNTs) into sensing devices. However, a practical sensor needs to have selective response in addition to sensitivity. Therefore, recent efforts have focused on efforts to increase selectivity in SWNT sensors.

Preparation and modification of carbon nanotubes: review of recent advances and applications in catalysis and sensing.

Single-walled carbon nanotubes (SWNTs) have become one of the most intensely studied nanostructures because of their unique properties. The inherent physical properties of carbon nanotubes make them ideal supports for metal nanoparticles. The use of electrodeposition to modify SWNTs in order to facilitate applications in areas related to catalysis and sensing is presented in this manuscript.

Recent progress in chemical detection with single-walled carbon nanotube networks.

Single-walled carbon nanotubes (SWNTs) have had significant impact on the development of gas sensors in the last decade. However, useful applications of SWNTs are limited by the lack of manufacturable routes to device formation. This Highlight article chronicles recent progress in this area and demonstrates the great promise of a new room temperature deposition method for SWNT networks in gas sensing applications.

High-Resolution Electrochemical Scanning Tunneling Microscopy (EC-STM) Flow-Cell Studies.

Atomic-level studies involving an electrochemical scanning tunneling microscope (EC-STM) flow-cell are presented. Multiple electrochemical atomic layer epitaxy (EC-ALE) cycles of CdTe formation were observed. For a binary compound (i.

Electrodeposition of Au-Cd alloy nanostructures on Au(111).

This report concerns an in-situ scanning tunneling microscopy study of the initial stages in the formation of a Au-Cd alloy on the Au(111) herringbone reconstruction. Although Au-Cd nanoclusters of alloy have been observed in sulfate electrolyte by this group, alloy "nanowires" were observed to form preferentially in the hcp regions between the sets of "soliton" walls of the reconstruction only in the presence of chloride. The nanowires were formed at -0.