Carbon nanotube 'ink' may pave way for thinner, lighter transistors, solar cells

Washington, Jan 11 (ANI): Scientists at Cornell and DuPont have used a simple chemical process to develop a new method of preparing carbon nanotubes for suspension in a semiconducting "ink," paving the way for thinner, lighter transistors and solar cells.

The new method, invented by Graciela B. Blanchet, a research fellow at DuPont, and George Malliaras, Cornell associate professor of materials science and engineering, involves treating carbon nanotubes with fluorine-based molecules.Carbon nanotubes hold potential to be used for transistors in low-cost, printable electronics, but only after large quantities of them have been converted into semiconductors. When grown in the lab, some carbon nanotubes are semiconducting while others are metallic, and they are difficult to separate from each other.

And Malliaras said that the mix usually turns out to be a major drawback in creating transistors from nanotubes.

Thus, the researchers focussed on a new, inexpensive way to eliminate the metallic tubes, preparing them for such applications as suspension in semiconducting ink for printing.

For this, they brought fluorine-based molecules into contact with the nanotubes. The fluorine molecules efficiently attacked or converted the metallic nanotubes via a process called cycloaddition, leaving the semiconducting tubes alone, and creating a perfect batch of solely semiconducting nanotubes.

"Our work suggests that careful control of the chemical reaction enables the complete conversion of metallic tubes without the degradation of semiconducting tubes," said Blanchet.

Malliaras added that the study should lead to exploration of a wide range of devices, such as novel organic photovoltaic structures.

The findings of the study are published in the latest issue of the journal Science. (ANI)