Conjugated Polymers for Solar Cells Incorporating the Dithienosilole Unit

Polymer Solar Cells (PSC) are widely studied as low cost, light weight and flexible alternative to silicon-based solar cells. The polymers suitable for this purpose should possess good solubility and filming properties and extended π-conjugated systems with high absorption coefficients, UV–Vis-NIR spectra ideally matching the solar spectrum, high hole mobility, and HOMO–LUMO energy levels suitable to be coupled with the acceptor species, such as fullerene derivatives. One of the newest monomeric units that can be used to build conjugated polymers for PSC is functionalized dithienosilole. This contribution will deal with the synthesis and properties of two different low band gap copolymers containing dithienosilole alternated to thienothiophene or to substituted bithiophene