2 Similar models were independently put forward by Michael Rice at Xerox Corp 3 and by Sergey A. Brazovski and Natasha Kirova in Moscow. 4 Experiments in the 1980s showed that solitons can be excited by photons and current injection as well as by doping. The details of how polymers carry current are still not fully understood. As Arthur Epstein of Ohio State University explained it, most models were initially based on long, isolated chains. Despite the uncertainty about the details of some models, researchers have nevertheless been able to make many materials nearly by design.
Many challenges remain.
A major one is to raise the carrier mobility and the conductivity, which are currently limited by the defects in the polymers. When cast from solution as thin films, the polymers remain largely a tangle of spaghetti-like strands. With improved ordering of the polymer chains, however, the conductivity could exceed those of even the best metals. Conducting polymers, which all have beautiful intense colors in solution, were known to luminesce when exposed to light, but the effect was always fleeting. Simple model of a pi-conjugated polymer.