At the heart of the Plextronics technology is the design and synthesis of high-performance conductive and semiconductive polymers, specifically regioregular polythiophenes. Key characteristics driving polymer design and synthesis include molecular weight, energy absorption bandgap, and end-group functionality. Plastics normally do not conduct electricity, but conducting polymers are synthesized by delocalizing electrons along conjugated polymer backbones. This is possible only with certain types of plastics, such as polythiophenes. Alan Heeger, Alan MacDiarmid, and Hideki Shirakawa received the 2000 Nobel Prize in Chemistry for discovering and developing conductive polymers.
The polymers have particular commercial potential in printed electronics, because they can be produced in roll-to-roll manufacturing systems on flexible substrates. One target application is the charging of batteries in remote locations, such as combat zones.
Plextronics built a Development Line in 2009 in Harmarville, Pa., to demonstrate larger-scale applications and to accelerate the development of inks that could be used in manufacturing processes. Development work has focused mainly on OPV device and ink engineering over the last couple of years, but the company plans to begin transitioning this year to running more OLED lighting panels.
Printed electronics and organic photovoltaics are two of the business development pillars in the Solvay Innovation Center, which was formed last year. The other two are nanotechnologies and renewable feedstocks. Solvay also has taken a minority stake in Polyera Corp., an Illinois company that develops materials for the printed electronics market.
Rollman told Design News that the OLED technology is closer to commercialization than the OPV technology. Plextronics last published an efficiency rating for its OPV cells about 18 months ago. At that time, the efficiency was better than 6 percent, but "we have become more sensitive about reporting that data, because of conflicting methods companies are using to report efficiency data."
Plextronics has 67 employees and expects to add up to eight more in the coming year.