Nanowerk February 10, 2022
An international team of researchers (Russia, Finland) studied carbon nanotube films conductivity in the terahertz and infrared bands. Some of the films 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 properties in the process. They discovered that shortening 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). Exposure to plasma results in a larger number of defects and, therefore, a larger number 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 low frequencies, because at low temperatures electrons lack kinetic energy to overcome potential barriers. They plan to continue studying modified films, including those stretched in one or more directions. According to the researchers, carbon nanotube films are more appealing for electronics applications as they are lighter, and more stable chemically and mechanically than metallic films. They can be tuned for specific applications…read more. TECHNICAL ARTICLE
Graphical abstract. Credit: Carbon, Volume 189, 15 April 2022, Pages 413-421Â