Plastic Transistors in Future Flexible Displays

A new organic semiconductors transistor production process was recently reported by scientists from Carnegie Mellon University. This development makes the production of plastic transistors with enhanced electrical and mechanical properties possible.

Nanowire assembly of a block copolymer (rr-PH3T and 57 percent PMA) on an OTS-8-treated silicon dioxide surface 
Nanowire assembly of a block copolymer
(rr-PH3T and 57 percent PMA) on an OTS-8-
treated silicon dioxide
surface (Credit: Carnegie Mellon)

A plastic transistor is made of an inherently conducting polymer (ICP) that provides the electronic switching ability inherent in a transistor. However, ICP’s are breakable and inelastic. To counter this problem scientists chemically link ICP’s with a grease-like elastic polymer, producing block copolymers. Although elasticity is enhanced in this way, the elastic polymers degrade the electrical performance of the transistor.

When the Carnegie Mellon scientists pretreated the transistor’s silicon dioxide platform with OTS-8 (a chemical that creates a grease-like coating) they found that transistors incorporating any of the four block copolymers conducted an electric charge with remarkable ease, even when the insulating polymer constituted more than half of the applied block copolymer.  

The head of the research group, Prof. Richard McCullough, reported to the Carnegie Mellon Press: “We were surprised and amazed with our finding… this is the first report that copolymers are good organic semiconductors … these results mean that we could soon design devices that are both flexible and highly functional”.

Future devices that may rely on this discovery are e-books that could be rolled like a newspaper. Such flexible display technology was recently reported by TFOT.

More information about the new technology can be found in the report of the Carnegie Mellon Press.