Carbon nanotube 'ink' may lead to thinner, lighter transistors and solar cells

January 8, 2009 By Anne Ju
An atomic force microscope image of semiconducting nanotubes, after the cycloaddition process of removing the metallic tubes.

(PhysOrg.com) -- Using a simple chemical process, scientists at Cornell and DuPont have invented a method of preparing carbon nanotubes for suspension in a semiconducting "ink," which can then be printed into such thin, flexible electronics as transistors and photovoltaic materials.

The method, which involves treating carbon nanotubes with fluorine-based molecules, is reported in the Jan. 9 issue of the journal Science (Vol. 323 No. 234). The research was jointly led by Graciela B. Blanchet, a research fellow at DuPont, and George Malliaras, Cornell associate professor of materials science and engineering and the Lester B. Knight Director of the Cornell NanoScale Science and Technology Facility. Helen Lu, a research chemist at Dupont, and Mandakini Kanungo, a former Cornell postdoctoral fellow now at Xerox, also worked on the project.

Carbon nanotubes are good candidates for transistors in low-cost, printable electronics, but only after large quantities of them have been converted into semiconductors. When carbon nanotubes are grown in the lab, some are semiconducting but others are metallic, and they are difficult to separate from each other.

An atomic force microscope image of both metallic and semiconducting carbon nanotubes, before the cycloaddition process of removing the metallic tubes.

This mix is a major drawback in creating transistors from nanotubes, Malliaras said. The Cornell/DuPont team concentrated on a new, inexpensive way to eliminate the metallic tubes, preparing them for such applications as suspension in semiconducting ink for printing.

To do so, the researchers brought fluorine-based molecules into contact with the nanotubes. Through a process called cycloaddition, the fluorine molecules efficiently attacked or converted the metallic nanotubes, 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," Blanchet said.

The work should lead to exploration of a wide range of devices, such as novel organic photovoltaic structures, Malliaras added.

For the past several years, scientists from Cornell and DuPont have worked together on a variety of projects involving flexible electronics. The research is funded by a grant from the U.S. Air Force for developing transistors from carbon nanotubes.

Provided by Cornell University

Explore further: Researchers make scalable arrays of 'building blocks' for ultrathin electronics

Related Stories

Could black phosphorus be the next silicon?

July 7, 2015

As scientists continue to hunt for a material that will make it possible to pack more transistors on a chip, new research from McGill University and Université de Montréal adds to evidence that black phosphorus could emerge ...

2-D nitrogenated crystals new potential rival for graphene

March 10, 2015

Researchers in South Korea have, for the first time, developed a simple technique to produce a two-dimensional nitrogen-containing crystal that has the capacity to be a potential rival to graphene and silicon as semi-conductor ...

Recommended for you

An engineered surface unsticks sticky water droplets

August 31, 2015

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets ...

Electrical circuit made of gel can repair itself

August 25, 2015

(Phys.org)—Scientists have fabricated a flexible electrical circuit that, when cut into two pieces, can repair itself and fully restore its original conductivity. The circuit is made of a new gel that possesses a combination ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.