Spectral signature of positive and negative charged states in doped and photoexcited low band-gap polydithienothiophenes

Spectroelectrochemical studies of polydithienothiophenes (pDTTs), low band-gap conjugated polymers with polythiophene-like chain, using in situ FTIR-ATR and ESR spectroscopy, are shown. Spectral results obtained during p- and n-doping, as well as photoinduced spectral effects, are compared. The formation of paramagnetic positive and negative charge carriers with unusually high g-values is described.