Despite their almost incomprehensibly small size a diameter about one ten-thousandth the thickness of a human hair single-walled carbon nanotubes come in a plethora of different "species," each with its own structure and unique combination of electronic and optical properties. Characterizing the structure and properties of an individual carbon nanotube has involved a lot of guesswork until now.
Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have developed a technique that can be used to identify the structure of an individual carbon nanotube and characterize its electronic and optical properties in a functional device.
"Using a novel high-contrast polarization-based optical microscopy set-up, we've demonstrated video-rate imaging and in-situ spectroscopy of individual carbon nanotubes on various substrates and in functional devices," says Feng Wang, a condensed matter physicist with Berkeley Lab's Materials Sciences Division. "For the first time, we can take images and spectra of individual nanotubes in a general environment, including on substrates or in functional devices, which should be a great tool for advancing nanotube technology."
Wang, who is also a professor with UC Berkeley's Physics Department, is the corresponding author of a paper describing this research in the journal Nature Nanotechnology. The paper is titled "High-throughput optical imaging and spectroscopy of individual carbon nanotubes in devices." Co-authors are Kaihui Liu, Xiaoping Hong, Qin Zhou, Chenhao Jin, Jinghua Li, Weiwei Zhou, Jie Liu, Enge Wang and Alex Zettl.
A single-walled carbon nanotube can be metallic or semiconducting depending on its exact structure. Semiconducting nanotubes can have very different electronic bandgaps, resulting in wildly different electronic or optical properties.
"To fully understand field-eff
|Contact: Lynn Yarris|
DOE/Lawrence Berkeley National Laboratory