Semiconducting Molecule Created

Scientists were finally able to modify a molecule to the extent that it could soon be possible to use it as a semiconductor. This is the first time this was achieved, and the team behind the investigation, based at the University of New Hampshire, is ecstatic about the results. Manufacturing flexible organic electronics, including such things as large displays, solar cells and radio frequency identification (RFID) tags, could therefore become possible in the near future, they add. Details of the investigation appear in the January 2010 issue of the respected Journal of the American Chemical Society.

The molecule that was modified in the new study belongs to a class of acenes, which are organic semiconductors, This particular compound features nine rings of benzene fused together in a linear manner, and is therefore called nonacene. It is also one of the most reliable members of the family, in terms of the electronic performance they are capable of achieving, However, their major problem is the fact that they oxidize very fast, which means that they are highly unstable.

“We have known that nonacene would have very desirable electronic properties, but it was just a tease, because you couldn't make it, you couldn't use it,” Professor of Organic Chemistry and Materials Science Glen Miller, who led the new research with two UNH undergraduate students, explains. The expert has been working on preparing stable, large acenes for the past three years. Using an approach that some might consider similar to the popular game LEGO, the researchers constructed a nonacene from several smaller components. Using small collections of chemicals that contained sulfur, known as arylthio functional groups, the team was able to produce stable compounds.

“The skeleton of the molecule is still there, but it's got additional functional groups attached to the skeleton,” Miller explains. “These compounds push all of these technologies further. Before our work, the thought of preparing flexible organic electronic devices using nonacene or a nonacene derivative was just a dream. With this major step forward, we are much closer to realizing the dream,” the expert adds. The journal paper detailing the finding is called “Design, Synthesis, and Characterization of a Persistent Nonacene Derivative.”