Photoinduced electron transfer in donor-acceptor double-cable polymers: Polythiophene bearing tetracyanoanthraquinodimethane moieties

To circumvent the problems of morphology and donor-acceptor phase segregati on in organic bulk heterojunction solar cells, double-cable materials, cons isting of a hole conducting conjugated polymer chain carrying pendant elect ron accepting moieties, are proposed. We report the electrochemical synthes is of a double-cable material consisting of a polythiophene backbone with c ovalently bound tetracyanoanthraquino-dimethane (TCAQ) moieties. Cyclic vol tammetry and UV-vis absorption measurements reveal that in this functional material both the polythiophene chain and the TCAQ moieties maintain their individual electrochemical and electronic ground state properties. Photoind uced absorption (PIA) and light-induced electron spin resonance (LESR) stud ies clearly indicate photoinduced electron transfer from the polythiophene backbone to the TCAQ moieties upon photoexcitation. The results of the PIA are comparatively studied with UV/vis and near-infrared absorption spectra upon electrochemical doping.