Semiconducting polymers, large, chain-like molecules made from repeating subunits, are increasingly drawing the attention of researchers because of their potential applications in organic electronic devices. Like most semiconducting materials, semiconducting polymers can be classified as p-type or n-type according to their conducting properties. Although p-type semiconducting polymers have seen dramatic improvements thanks to recent advances, the same cannot be said about their n-type counterparts, whose electron conduction (or ‘electron mobility’) is still poor.
Unfortunately, high-performance n-type semiconducting polymers are necessary for many green applications, such as in types of solar cells. The main challenges holding back the development of n-type semiconducting polymers are the limited molecular design strategies and synthesis procedures available. Among the existing synthesis methods, DArP (which stands for ‘direct arylation polycondensation’) has shown promising results for producing n-type semiconducting polymers in an environmentally friendly and efficient way. However, until now, the building blocks (monomers) used in the DArP method were required to have an orienting group in order to produce polymers reliably, and this severely limited the applicability of DArP to make high-performance semiconducting polymers.