Conjugated Oligomers and Polymers Containing Dithienosilole Units

Dithienosilole (DTS) with a silole ring fused to a bithiophene unit are of interest. The condensed tricyclic system shows extended conjugation compared with that of silicon-free bithiophene. This is because the planar structure of the bithiophene unit is retained by the silicon bridge and also because the interaction between the silicon sigma* and bithiophene pi* orbitals lowers the LUMO energy level. This review describes the synthesis and properties of conjugated oligomers and polymers containing DTS units in their backbones. The applications of DTS-containing oligomers and polymers to organic light-emitting diodes, organic photovoltaic cells, and organic thin-film transistors are also introduced.