The contribution of inner layers is crucial, and this has serious implications when it particularly comes to fabricating electronic devices such as transistors and molecular interconnects. The work reported in Nano Letters (DOI: 10.1021/nl070072p) addresses essential issues related to the electronic properties of carbon nanotubes, as an understanding of their behaviour at the atomic level is required to fully exploit the tremendous opportunities that these systems could offer in the development of practical nanoscale devices.
Single wall carbon nanotubes can be regarded as individual sheets (one atom thick) of graphite which are wrapped up to form tubes. It is the diameter of the tube and the degree of helicity in this wrapping which determine the electronic properties. Different configurations can result in the tube behaving either as a metallic conductor or as a semiconductor, and this theoretically-predicted relationship between the structure and electronic properties has been confirmed using scanning tunnelling microscopy.
It is also possible to form multi-wall nanotubes comprising several tubes, one inside another (like layers of an onion, or a set of Russion dolls). Whereas single-walled carbon nanotubes have been researched and well characterised for many years now, less is known about the multi-wall tubes. How strong is the electrical coupling between layers? How does the helicity of the inner layers affect electrical conduction of the multi-wall tube?
The experiments carried out at the University of Surrey used scanning tunnelling microscopy of double-walled carbon nanotubes to demonstrate an explicit correlation between the helicity of the constituent tubes, their electronic coupling and the overall electronic structure. Cristina Giusca, the lead author of the paper said: “The work is of fundamental importance to the carbon community as it shows the first evidence for a direct correlation between the electronic properties of multiwall carbon nanotubes and the diameter and chiral indices (helicity) of the inner shells”.
Professor Ravi Silva, who leads the Advanced Technology Institute at the University of Surrey, indicated that “This is a fine example of the cutting edge research undertaken at the Institute which combines the very best in fundamental research with sound theoretical backing. The work is of crucial importance to all of us conducting research in carbon nanotubes and other forms of quantum transport studies in 1D structures which clearly highlights the importance of the electronic interaction between adjacent layers, which were previously considered to be less important. This work will add new vigour to those examining the use of carbon nanotubes for interconnects in the IC industry. Having only metallic carbon nanotubes may now not be necessary in the design of interconnect wires between semiconductors if multi-walled nanotubes are to be used for this application.”
Stuart Miller | alfa
Protecting the power grid: Advanced plasma switch for more efficient transmission
17.08.2018 | DOE/Princeton Plasma Physics Laboratory
Unraveling the nature of 'whistlers' from space in the lab
15.08.2018 | American Institute of Physics
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
17.08.2018 | Life Sciences
17.08.2018 | Event News
17.08.2018 | Materials Sciences