Polymers have display potential

A new type of semiconducting polythiophene with high charge-carrier mobility could potentially be used in flexible, lightweight, and ultimately large-area displays, according to Iain McCulloch and Martin Heeney at Merck Chemicals, Southampton, England, and coworkers. They designed the polymers (example shown) to assemble into large crystalline domains from a liquid-crystal phase (Nat. Mater., published online March 19, dx.doi.org/10.1038/nmat1612). "This exceptional crystallinity gives rise to a dramatic improvement in performance relative to other semiconducting polymers," McCulloch says. When fabricated as thin films, the polymers exhibit extremely well oriented and closely packed polymer backbones. Their extended planar ?-electron systems allow close intermolecular ? -? distances, which facilitate charge-carrier mobilities equivalent to those of amorphous silicon, the current material of choice in large-area electronics.