[Nanomaerials] - Carbon nanotube open up new prospects for electronics

Physicists from Mippt and Skoltech Have Found A Way to Modify and Purposaly Tune the Electronic Properties of Carbon Nanotubes to Meet the Requirements of Novel Electronic Devices.
The Paper is published in Carbon ("Terahertz-Infrared Spectroscopy of Wafer-Scale Films of Single-Walled Carbon Nanotubes Treated by Plasma").
Carbon nanomaterials Form an Extensive Class of Compound that Graphine, Fullerenes, Nanotubes, Nanofibers, and More. Although the Physical Properties of Many of these Materials Already Appear in TextBooks, Scientists Continue to Create New Structures and Find Ways to Use them in Real-Life Applications. Macro structures designed as randomly guidance movies made of carbon nanotubes look like thin cobwebs with an are Area Reaching Several Dozen Square Centimeters and Thickness of Only A Few Nanometers.
Carbon nanotube movies Display an amazing combination of physic and chemical property, such as mechanical stability, flexibility, stretchaibility, excellent adhesion to various substrate, chemical inertness and exceptional electrical and optical fartes.
UNLIKE METALLIC FILMS, THERE HIGHLY CONDUCTING FILMS ARE LIGHT AND FLEXIBLE AND, THEREFORE, CAN BE USED IN VARIOUS ELECTRICAL DEVICES, SUCH AS ELECTromagnetic Shields, Modulators, Antennas, Bolometers, AND SO ON.
Mippt and skoltech Scientists Studied Films Conductivity in the Terahertz and Infrared Bands Using Films Synthesized by the Gas Phase Deposition Method. Some of the movies were made of nanotubes with lengths varying from 0.3 to 13 µm, While Others were treated with oxygen plasma for 100 to 400 seconds and changed their electrodynamic properies in the process.
In An Earlier Study, The Authors Proven that Condeductivity of High-Quality Pistine Films can be Accurately Described Using the Conductivity Model Valid for Metals. In these films, free electrons have enough energy to overcome potential barriers at the intersections of individual nanotubes and can move quite easy over the whole movie, which results in high conductivity.
However, Shortering Tubes Length (Down to 0.3 µm) OR Exposing Films to Plasma (For Longer than 100 S) leads to a drop in conductivity at low terahertz frequencies (<0.3 THZ). The Team Discovered That in Both Cases Condeductivity Changes in Much the Same Way and Produces Similar Results. Exposure to plasma results in a larger love of defects and, therefore, a larger amnt of potential barriers for itinerant electrons.
For Shorter Nanotubes, The Number of Barriers Per Unit Area Increases, Too. The Barriers Strongly Affect Conductivity of Both Nanotubes and Films at Direct Current (DC) and Fairly Low Frequencies, Becuse at Low Temperactures Electrons Lack Kinetic Energy to Overcoma Potential Barriers.
The Authors Showed that at High Enough Frequencies Electrons Move FreeLy As If the Barriers Were Not There. At low frequencies and in the DC Case, movies made up of short or plasma-treaded tubes exhibit a high temperature coefficient of resistance (TCR) Which Shows How Resistance Changes with temperature.
For Plasma Exposure of Over 100 Seconds Or nanotube Lengths Below 0.3 µm, TCR Reaches saturation. The effect can be considered as a precursor of tcr reduction in the movies that are exhibition to plasma for a very long time when separate tubes become severely damaged and lose their peculiar electric farties.
MIPT and Skoltech Researchers Plan To Continue Studying Modified Films, Including Those Stretched in one or more directions. Boris Gorshunov, A Co-Author of the Paper and Head of the Mipt Laboratory of Terahertz Spectroscopy, Comments: "In contrast to nanotubes that has long been studied in great detail, Research on macro objects, such as nanotube movies, Started only. and More Stable Chemically and Mechanically Than Metallic Films and, ThereFore, Are More Appealing for Electronics Applications. Ubiquitous in Telecommunications is of Particular Relivance. "

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