Replacing traditional rigid silicon wafers with semiconductors made from flexible polymers would herald an age of advanced, ‘wearable’ electronics. Switching to these semiconductors, known as organic field-effect transistors (OFETs), would also reduce manufacturing costs significantly. However, most plastic materials have trouble moving electrons and their polar opposites—positively charged empty ‘holes’ inside semiconductor lattices—with sufficient speed for electronic amplification.
Prashant Sonar and co-workers from the A*STAR Institute of Materials Research and Engineering in Singapore have now developed a polymer for solution-based OFET processing that has inherently high carrier mobility and extraordinary air stability. Unlike silicon, polymers are difficult to pack into crystalline structures containing regular pathways for charge carriers. The team’s polymer, however, has specifically designed hydrogen bond interactions that create ordered networks for transporting electrons and holes.
Most polymers used in OFETs have a ‘donor–acceptor’ arrangement of conjugated molecules to enhance the mobility of charge carriers. Using special catalysts, chemists can link together small units of electron-rich and electron-poor aromatic molecules to form an alternating chain of ‘block’ co-polymers. Sonar and co-workers investigated whether fluorenone—an inexpensive and chemically stable molecule with three fused aromatic rings and a central carbonyl unit—could act as a new type of acceptor block for OFET polymers.
Read more at: Phys.org