Luminescence from oligothiophenes and thiophene-based oligomers

We have studied luminescence properties of oligothiophenes and thiophene-based oligomers. The thiophene-based oligomers have the well-barrier-well structures in quasi-one-dimensional backbone chains, where the well parts are the oligothiophenes with different conjugation lengths and the barrier parts are the non-visibly luminescent materials with lager energy gaps. Luminescence properties of thiophene-based oligomers such as luminescence yield, luminescence lifetime, and luminescence wavelength can be controlled by changing the conjugation length of the well part and the barrier structure. The size dependence of the optical properties of oligothiophenes shows that excitons are localized within two thiophene rings.